LM4128BMF-3.3中文资料

ADVANCE INFORMATIONOctober 2007 LM3410525kHz/1.6MHz, Constant Current Boost and SEPIC LED Driver with Internal CompensationGeneral DescriptionThe LM3410 constant current LED driver is a monolithic, high frequency, PWM step-up DC/DC converter in 5-pin SOT23, 6-pin LLP, & 8-pin eMSOP packages. With a minimum of ex-ternal components the LM3410 is easy to use. It can drive 2.5A typical peak currents with an internal 160mΩ NMOS switch. Switching frequency is internally set to either 525kHz or 1.60MHz, allowing the use of extremely small surface mount inductors and chip capacitors. Even though the oper-ating frequency is high, efficiencies up to 88% are easy to achieve. External shutdown is included, featuring an ultra-low stand-by current of 80nA. The LM3410 utilizes current-mode control and internal compensation to provide high-perfor-mance over a wide range of operating conditions. Additional features include dimming, pulse-by-pulse current limit, and thermal shutdown.Features■Space Saving SOT23-5 & 6-LLP Package■Wide Input voltage range of 2.7V to 5.5V■Wide Output voltage range of 3V to 24V■ 2.1A switch current over full temperature range ■Two High Switching Frequencies Available:—525 kHz (LM3410-Y)—1.6 MHz (LM3410-X)■160 mΩ NMOS Switch■190 mV Internal Voltage Reference■Internal Soft-Start■Current-Mode, PWM Operation Applications■Portable Illumination■LED Backlight Current Source■LiIon Backlight OLED Driver■Handheld DevicesTypical Boost Application Circuit30038501© 2007 National Semiconductor LM3410 525kHz/1.6MHz, Constant Current Boost and SEPIC LED DriverConnection DiagramsTop View300385035-Pin SOT23Top View300385046-Pin LLPTop View300385058-Pin eMSOPOrdering InformationFrequencyOrder Number Package Type Package DrawingSupplied As 525 kHzLM3410YMF SOT23-5MF05A 1000 units tape & reel LM3410YMFX3000 units tape & reel LM3410YSD LLP-6SDE06A 1000 units tape & reel LM3410YSDX 4500 units tape & reel LM3410YMY eMSOP-8MUY08A 1000 units tape & reel LM3410YMYX 3500 units tape & reel 1.6 MHzLM3410XMF SOT23-5MF05A 1000 units tape & reel LM3410XMFX3000 units tape & reel LM3410XSD LLP-6SDE06A 1000 units tape & reel LM3410XSDX 4500 units tape & reel LM3410XMY eMSOP-8MUY08A1000 units tape & reel LM3410XMYX3500 units tape & reel 2L M 3410Pin Description - 5-Pin SOT23Pin Name Function1SW Output switch. Connect to the inductor, output diode.2GND Signal and power ground pin. Place the bottom resistor of the feedback network as close as possible to this pin.3FB Feedback pin. Connect FB to external resistor divider to set output voltage.4DIM Dimming & shutdown control input. Logic high enables operation. Duty Cycle from 0 to 100%. Do not allow this pin to float or be greater than VIN + 0.3V.5VIN Supply voltage for power stage, and input supply voltage.Pin Description - 6 Pin LLPPin Name Function1PGND Power ground pin. Place PGND and output capacitor GND close together.2VIN Supply voltage for power stage, and input supply voltage.3DIM Dimming & shutdown control input. Logic high enables operation. Duty Cycle from 0 to 100%. Do not allow this pin to float or be greater than VIN + 0.3V.4FB Feedback pin. Connect FB to external resistor divider to set output voltage.5AGND Signal ground pin. Place the bottom resistor of the feedback network as close as possible to this pin & pin 4.6SW Output switch. Connect to the inductor, output diode.DAP GND Signal & Power ground. Connect to pin 1 & pin 5 on top layer. Place 4-6 vias from DAP to bottom layer GND plane.Pin Description - 8 Pin eMSOPPin Name Function1-No Connect2PGND Power ground pin. Place PGND and output capacitor GND close together.3VIN Supply voltage for power stage, and input supply voltage.4DIM Dimming & shutdown control input. Logic high enables operation. Duty Cycle from 0 to 100%. Do not allow this pin to float or be greater than VIN + 0.3V.5FB Feedback pin. Connect FB to external resistor divider to set output voltage.6AGND Signal ground pin. Place the bottom resistor of the feedback network as close as possible to this pin & pin 5 7SW Output switch. Connect to the inductor, output diode.8-No ConnectDAP GND Signal & Power ground. Connect to pin 2 & pin 6 on top layer. Place 4-6 vias from DAP to bottom layer GND plane.LM3410Physical Dimensions inches (millimeters) unless otherwise noted6-Lead LLP PackageNS Package Number SDE06A5-Lead SOT23-5 Package NS Package Number MF05A 4L M 3410LM3410 8-Lead eMSOP PackageNS Package Number MUY08ANotesL M 3410 525k H z /1.6M H z , C o n s t a n t C u r r e n t B o o s t a n d S E P I C L E D D r i v e rTHE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. NATIONAL MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS PUBLICATION AND RESERVES THE RIGHT TO MAK E CHANGES TO SPECIFICATIONS AND PRODUCT DESCRIPTIONS AT ANY TIME WITHOUT NOTICE. NO LICENSE, WHETHER EXPRESS,IMPLIED, ARISING BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT.TESTING AND OTHER QUALITY CONTROLS ARE USED TO THE EXTENT NATIONAL DEEMS NECESSARY TO SUPPORT NATIONAL’S PRODUCT WARRANTY. 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All other brand or product names may be trademarks or registered trademarks of their respective holders.Copyright© 2007 National Semiconductor CorporationFor the most current product information visit us at National Semiconductor Americas Customer Support Center Email:new.feedback@ Tel: 1-800-272-9959National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530-85-86Email: europe.support@ Deutsch Tel: +49 (0) 69 9508 6208English Tel: +49 (0) 870 24 0 2171Français Tel: +33 (0) 1 41 91 8790National Semiconductor Asia Pacific Customer Support Center Email: ap.support@National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507Email: jpn.feedback@ Tel: 81-3-5639-7560。

TL F 8649DP8428 NS32828 DP8429 NS328291Megabit High Speed Dynamic RAM Controller DriversSeptember 1991DP8428 NS32828 DP8429 NS328291Megabit High Speed Dynamic RAM Controller DriversGeneral DescriptionThe DP8428and DP84291M DRAM Controller Drivers are designed to provide ‘‘No-Waitstate’’CPU interface to Dy-namic RAM arrays of up to 8Mbytes and larger The DP8428and DP8429are tailored for 32-bit and 16-bit sys-tem requirements respectively Both devices are fabricated using National’s new oxide isolated Advanced Low power Schottky (ALS)process and use design techniques which enable them to significantly out-perform all other LSI or dis-crete alternatives in speed level of integration and power consumptionEach device integrates the following critical 1M DRAM con-troller functions on a single monolithic device ultra precise delay line 9bit refresh counter fall-through row column and bank select input latches Row Column address mux-ing logic on-board high capacitive-load RAS CAS Write Enable and Address output drivers and precise control sig-nal timing for all the aboveIn order to specify each device for ‘‘true’’worst case operat-ing conditions all timing parameters are guaranteed while the chip is driving the capacitive load of 88DRAMs includ-ing trace capacitance The chip’s delay timing logic makes use of a patented new delay line technique which keeps AC skew to g 3ns over the full V CC range of g 10%and tem-perature range of b 55 C to a 125 C The DP8428and DP8429guarantee a maximum RASIN to CASOUT delay of 80ns or 70ns even while driving an 8Mbyte memory array with error correction check bits included Two speed select-ed options of these devices are shown in the switching characteristics section of this document (Continued)FeaturesYMakes DRAM interface and refresh tasks appear virtu-ally transparent to the CPU making DRAMs as easy touse as static RAMsYSpecifically designed to eliminate CPU wait states up to 10MHz or beyondYEliminates 20discrete components for significant board real estate reduction system power savings and the elimination of chip-to-chip AC skewing Y On-board ultra precise delay lineYOn-board high capacitive RAS CAS WE and Address drivers (specified driving 88DRAMs directly)Y AC specified for directly addressing up to 8Mbytes Y Low power high speed bipolar oxide isolated process YDownward pin and function compatible with 256k DRAM Controller Drivers DP8409A DP8417 DP8418 and DP8419ContentsY System and Device Block DiagramsY Recommended Companion ComponentsY Device Connection Diagrams and Pin Definitions Y Device Differences DP8428vs DP8429YMode of Operation(Descriptions and Timing Diagrams)Y Application Description and DiagramsYDC AC Electrical Specifications Timing Diagrams and Test ConditionsSystem DiagramTL F 8649–1TRI-STATE is a registered trademark of National Semiconductor CorpPAL is a registered trademark of and used under license with Monolithic Memories Inc C 1995National Semiconductor CorporationRRD-B30M105 Printed in U S AGeneral Description(Continued)With its four independent RAS outputs and ten multiplexedaddress outputs the DP8429can support up to four banksof64k 256k or1M DRAMs Two bank select pins B1andB0 are decoded to activate one of the RAS signals duringan access leaving the three non-selected banks in thestandby mode(less than one tenth of the operating power)with data outputs in TRI-STATE The DP8428’s one Bank Select pin B1 enables2banks automatically during an ac-cess in order to provide an optimum interface for32-bit mi-croprocessorsThe DP8428and DP8429each have two mode-select pinsallowing for two refresh modes and two access modes Re-fresh and access timing may be controlled either externally or automatically The automatic modes require a minimum of input control signalsA refresh counter is on-chip and is multiplexed with the row and column inputs Its contents appear at the address out-puts of the DP8428or DP8429during any refresh and are incremented at the completion of the refresh Row Column and bank address latches are also on-chip However if the address inputs to the DP8428or DP8429are valid through-out the duration of the access these latches may be operat-ed in the fall-through modeEach device is available in either the52pin Ceramic DIP or the low cost JEDEC standard68pin Plastic Chip Carrier (PCC)packageFunctional Block DiagramsDP8429TL F 8649–22Functional Block Diagrams(Continued)DP8428TL F 8649–3System Companion ComponentsDevice FunctionDP84300Programmable Refresh Timer for DP84xx DRAM ControllerDP84412NS32008 16 32to DP8409A 17 18 19 28 29InterfaceDP84512NS32332to DP8417 18 19 28 29InterfaceDP8432268000 08 10to DP8409A 17 18 19 28 29Interface(up to8MHz)DP8442268000 08 10to DP8409A 17 18 19 28 29Interface(up to12 5MHz)DP8452268020to DP8417 18 19 28 29InterfaceDP844328086 88 186 188to DP8409A 17 18 19 28 29InterfaceDP8453280286to DP8409A 17 18 19 28 29InterfaceDP8400-216-Bit Expandable Error Checker Corrector(E2C2)DP8402A32-Bit Error Detector And Corrector(EDAC)3Connection DiagramsDual-In-Line PackageTL F 8649–4Dual-In-Line PackageTL F 8649–5Order Number DP8428D-70 DP8428D-80orDP8429D-70 DP8429D-80See NS Package Number D52APlastic Chip Carrier PackageTL F 8649–6Plastic Chip Carrier PackageTL F 8649–7Order Number DP8428V-70 DP8428V-80orDP8429V-70 DP8429V-80See NS Package Number V68A4DP8428vs DP8429The DP8428DYNAMIC RAM CONTROLLER DRIVER is identical to the DP8429with the exception of two functional differences incorporated to improve performance with32-bit microprocessors1)Pin28(B1)is used to enable disable a pair of RAS out-puts and pin29(B0on the DP8429)is a no connect When B1is low RAS0and RAS1are enabled such that they both go low during an access When B1is high RAS2and RAS3are enabled This feature is useful when driving words of32bits or more since each RAS would be driving only one half of the word By distributing the load on each RAS line in this way the DP8428will meet the same AC specifications driving2banks of32DRAMs each as the DP8429does driving4banks of16bits each 2)The hidden refresh function available on the DP8429hasbeen disabled on the DP8428in order to reduce the amount of setup time necessary from CS going low to RASIN going low during an access of DRAM This param-eter called t CSRL1 is5ns for the DP8428whereas it is 34ns for the DP8429 The hidden refresh function al-lowed only a very small increase in system performance at microprocessor frequencies of10MHz and above Pin DefinitionsV CC GND GND b V CC e5V g10% The three supply pins have been assigned to the center of the package to reduce voltage drops both DC and AC There are two ground pins to reduce the low level noise The second ground pin is located two pins from V CC so that decoupling capacitors can be inserted directly next to these pins It is important to adequately decouple this device due to the high switching currents that will occur when all10address bits change in the same direction simultaneously A recom-mended solution would be a1m F multilayer ceramic capaci-tor in parallel with a low-voltage tantalum capacitor both connected as close as possible to GND and V CC to reduce lead inductance See Figure belowTL F 8649–8 Capacitor values should be chosen depending on the particular applicationR0–R9 Row Address InputsC0–C9 Column Address InputsQ0–Q9 Multiplexed Address Outputs–This address is selected from the Row Address Input Latch the Column Address Input Latch or the Refresh CounterRASIN Row Address Strobe Input–RASIN directly con-trols the selected RAS output when in an access mode and all RAS outputs during hidden or external refreshR C(RFCK)–In the auto-modes this pin is the external refresh clock input one refresh cycle should be performed each clock period In the external access mode it is Row Column Select Input which enables either the row or column address input latch onto the output busCASIN(RGCK)–In the auto-modes this pin is the RAS Generator Clock input In external access mode it is the Column Address Strobe input which controls CAS directly once columns are enabled on the address outputsADS Address(Latch)Strobe Input–Row Address Col-umn Address and Bank Select Latches are fall-through with ADS high latching occurs on high-to-low transition of ADS CS Chip Select Input–When high CS disables all ac-cesses Refreshing however in both modes0and1is not affected by this pinM0 M2(RFSH) Mode Control Inputs–These pins select one of the four available operational modes of the DP8429 (see Table III)RFI 0 Refresh Input Output–In the auto-modes this pin is the Refresh Request Output It goes low following RFCK indicating that no hidden refresh was performed while RFCK was high When this pin is set low by an external gate the on-chip refresh counter is reset to all zeroesWIN Write Enable InputWE Write Enable Output–WE follows WIN unconditionally RAHS Row Address Hold Time Select–Selects the t RAH to be guaranteed by the DP8428or DP8429delay line to allow for the use of fast or slow DRAMsCAS Column Address Strobe Output–In mode5and in mode4with CASIN low before R C goes low CAS goes low automatically after the column address is valid on the address outputs In mode4CAS follows CASIN directly af-ter R C goes low allowing for nibble accessing CAS is al-ways high during refreshRAS0–3 Row Address Strobe Outputs–The enabled RAS output(see Table II)follows RASIN directly during an access During refresh all RAS outputs are enabled5Pin Definitions(Continued)B0 B1 Bank Select Inputs–These pins are decoded to enable one or two of the four RAS outputs during an access (see Table I and Table II)TABLE I DP8429Memory Bank DecodeBank Select(Strobed by ADS)Enabled RAS nB1B000RAS001RAS110RAS211RAS3TABLE II DP8428Memory Bank DecodeBank Select(Strobed by ADS)Enabled RAS nB1NC0X RAS0 RAS11X RAS2 RAS3Conditions for All ModesINPUT ADDRESSINGThe address block consists of a row-address latch a col-umn-address latch and a resettable refresh counter The address latches are fall-through when ADS is high and latch when ADS goes low If the address bus contains valid ad-dresses until after CAS goes low at the end of the memory cycle ADS can be permanently high Otherwise ADS must go low while the addresses are still validDRIVE CAPABILITYThe DP8429has timing parameters that are specified driv-ing the typical capacitance(including traces)of88 5V-only DRAMs Since there are4RAS outputs each is specified driving one-fourth of the total memory CAS WE and the address outputs are specified driving all88DRAMsThe graph in Figure10may be used to determine the slight variations in timing parameters due to loading conditions other than88DRAMsBecause of distributed trace capacitance and inductance and DRAM input capacitance current spikes can be creat-ed causing overshoots and undershoots at the DRAM in-puts that can change the contents of the DRAMs or even destroy them To reduce these spikes a damping resistor (low inductance carbon)should be inserted between the DP8429outputs and the DRAMs as close as possible tothe DP8429 The damping resistor values may differ de-pending on how heavily an output is loaded These resistors should be determined by the first prototypes(not wire-wrapped due to the larger distributed capacitance and in-ductance) Resistors should be chosen such that the tran-sition on the control outputs is critically damped Typical values will be from15X to100X with the lower values be-ing used with the larger memory arrays Note that AC pa-rameters are specified with15X damping resistors For more information see AN-305‘‘Precautions to Take When Driving Memories’’DP8429DRIVING ANY256k or1M DRAMSThe DP8429can drive any256k or1M DRAMs 256k DRAMs require18of the DP8429’s address inputs to select one memory location within the DRAM RAS-only refreshing with the nine-bit refresh-counter on the DP8429makes CAS before RAS refreshing available on256k DRAMs unneces-sary(see Figure1a)1Mbit DRAMs require the use of all10of the DP8429Ad-dress Outputs(see Figure1b)READ WRITE AND READ-MODIFY-WRITE CYCLESThe output signal WE determines what type of memory access cycle the memory will perform If WE is kept high while CAS goes low a read cycle occurs If WE goes low before CAS goes low a write cycle occurs and data at DI (DRAM input data)is written into the DRAM as CAS goes low If WE goes low later than t CWD after CAS goes low firsta read occurs and DO(DRAM output data)becomes validthen data DI is written into the same address in the DRAM as WE goes low In this read-modify-write case DI and DO cannot be linked together WE always follows WIN directly to determine the type of access to be performedPOWER-UP INITIALIZEWhen V CC is first applied to the DP8429 an initialize pulse clears the refresh counter and the internal control flip-flops Mode Features SummaryY4modes of operation 2access and2refreshY Automatic or external selected by the userY Auto access mode provides RAS row to column change and then CAS automaticallyY Choice between two different values of t RAH in auto-ac-cess modeY CAS controlled independently in external control mode allowing for nibble mode accessingY Automatic refreshing can make refreshes transparent to the systemY CAS is inhibited during refresh cycles6DP8428 DP8429Mode DescriptionsMODE 0–EXTERNALLY CONTROLLED REFRESHFigure 2shows the Externally Controlled Refresh timing In this mode the refresh counter contents are multiplexed to the address outputs All RAS outputs are enabled to follow RASIN so that the row address indicated by the refresh counter is refreshed in all DRAM banks when RASIN goes low The refresh counter increments when RASIN goes high RFSH should be held low at least until RASIN goes high (they may go high simultaneously)so that the refresh address remains valid and all RAS outputs remain enabled throughout the refreshA burst refresh may be performed by holding RFSH low and toggling RASIN until all rows are refreshed It may be useful in this case to reset the refresh counter just prior to begin-ning the refresh The refresh counter resets to all zeroes when RFI O is pulled low by an external gate The refresh counter always counts to 511before rolling over to zero If there are 128or 256rows being refreshed then Q7or Q8 respectively going high may be used as an end-of-burst indicatorIn order that the refresh address is valid on the address outputs prior to the RAS lines going low RFSH must go low before RASIN The setup time required is given by t RFLRL in the Switching Characteristics This parameter may be ad-justed using Figure 10for loading conditions other than those specifiedTABLE III DP8428 DP8429Mode Select Options Mode (RFSH)M0Mode of Operation M2000Externally Controlled Refresh101Auto Refresh–Forced 410Externally Controlled Access511Auto Access (Hidden Refresh)DP8428 DP8429Interface Between System and DRAM BanksTL F 8649–12All 9Bits of Refresh Counter UsedFIGURE 1a DP8428 DP8429with 256k DRAMsTL F 8649–25All 9Bits of Refresh Counter UsedFIGURE 1b DP8428 DP8429with 1M DRAMs7DP8428 DP8429Mode Descriptions(Continued)Indicates Dynamic RAM Parameters TL F 8649–13FIGURE2a External Control Refresh Cycle(Mode0)TL F 8649–14FIGURE2b Burst Refresh Mode08DP8428 DP8429Mode Descriptions(Continued)MODE1–AUTOMATIC FORCED REFRESHIn Mode1the R C(RFCK)pin becomes RFCK(refresh cycle clock)and the CASIN(RGCK)pin becomes RGCK (RAS generator clock) If RFCK is high and Mode1is en-tered then the chip operates as if in MODE0(externally controlled refresh) with all RAS outputs following RASIN This feature of Mode1may be useful for those who want to use Mode5(automatic access)with externally controlled refresh By holding RFCK permanently high one need only toggle M2(RFSH)to switch from Mode5to external re-fresh As with Mode0 RFI O may be pulled low by an ex-ternal gate to reset the refresh counterWhen using Mode1as automatic refresh RFCK must be an input clock signal One refresh should occur each period of RFCK If no refresh is performed while RFCK is high then when RFCK goes low RFI O immediately goes low to indi-cate that a refresh is requested (RFI O may still be used to reset the refresh counter even though it is also used as a refresh request pin however an open-collector gate should be used to reset the counter in this case since RFI O is forced low internally for a request) After receiving the refresh request the system must allow a forced refresh to take place while RFCK is low External logic can monitor RFRQ(RFI O)so that when RFRQ goes low this logic will wait for the access currently in progress to be completed before pulling M2(RFSH)low to put the DP8429in mode1 If no access is taking place when RFRQ occurs then M2may immediately go low Once M2is low the refresh counter contents appear at the address outputs and RAS is generated to perform the refreshAn external clock on RGCK is required to derive the refresh RAS signals On the second falling edge of RGCK after M2 is low all RAS lines go low They remain low until two more falling edges of RGCK Thus RAS remains high for one to two periods of RGCK after M2goes low and stays low for two periods In order to obtain the minimum delay from M2 going low to RAS going low M2should go low t RFSRG be-fore the falling edge of RGCKThe Refresh Request on RFI O is terminated as RAS goes low This signal may be used to end the refresh earlier than it normally would as described above If M2is pulled highTL F 8649–15j RFCK goes lowk RFRQ goes low if no hidden refresh occurred while RFCK was highl Next RASIN starts next accessm m P acknowledges refresh request n Forced refresh RAS starts after l T (l t RP)o Forced refresh RAS ends RFRQp m P removes refresh acknowledgeFIGURE3 DP8428 DP8429Performing a Forced Refresh(Mode5x1x5)with Various Microprocessors9DP8428 DP8429Mode Descriptions(Continued)while the RAS lines are low then the RASs go high t RFRH later The designer must be careful however not to violate the minimum RAS low time of the DRAMs He must also guarantee that the minimum RAS precharge time is not vio-lated during a transition from mode1to mode5when an access is desired immediately following a refreshIf the processor tries to access memory while the DP8429is in mode1 WAIT states should be inserted into the proces-sor cycles until the DP8429is back in mode5and the de-sired access has been accomplished(see Figure9) Instead of using WAIT states to delay accesses when re-freshing HOLD states could be used as follows RFRQ could be connected to a HOLD or Bus Request input to the system When convenient the system acknowledges the HOLD or Bus Request by pulling M2low Using this scheme HOLD will end as the RAS lines go low(RFI O goes high) Thus there must be sufficient delay from the time HOLD goes high to the DP8429returning to mode5 so that the RAS low time of the DRAMs isn’t violated as de-scribed earlier(see Figure3for mode1refresh with Hold states)To perform a forced refresh the system will be inactive for about four periods of RGCK For a frequency of10MHz this is400ns To refresh128rows every2ms an average of about one refresh per16m s is required With a RFCK period of16m s and RGCK period of100ns DRAM accesses are delayed due to refresh only2 5%of the time If using the Hidden Refresh available in mode5(refreshing with RFCK high)this percentage will be even lowerMODE4-EXTERNALLY CONTROLLED ACCESSIn this mode all control signal outputs can be controlled directly by the corresponding control input The enabled RAS output follows RASIN CAS follows CASIN(with R C low) WE follows WIN and R C determines whether the row or the column inputs are enabled to the address outputs (see Figure4)With R C high the row address latch contents are enabled onto the address bus RAS going low strobes the row ad-dress into the DRAMs After waiting to allow for sufficient row-address hold time(t RAH)after RAS goes low R C can go low to enable the column address latch contents onto the address bus When the column address is valid CAS going low will strobe it into the DRAMs WIN determines whether the cycle is a read write or read-modify-write ac-cess Refer to Figures5a and5b for typical Read and Write timing using mode4Page or Nibble mode may be performed by toggling CASIN once the initial access has been completed In the case of page mode the column address must be changed beforeResistors required depends on DRAM loadDRAMs Maybe16k 64k 256k 1MFor4Banks can drive16data bitsa6Check Bits for ECCFor2Banks can drive32data bitsa7Check Bits for ECCFor1Bank can drive64data bitsa8Check Bits for ECCTL F 8649–16 FIGURE4 Typical Application of DP8429Using External Control Access and Refresh in Modes0and410DP8428 DP8429Mode Descriptions(Continued)TL F 8649–17FIGURE5a Read Cycle Timing(Mode4)TL F 8649–18FIGURE5b Write Cycle Timing(Mode4)11DP8428 DP8429Mode Descriptions(Continued)CASIN goes low to access a new memory location(see Figure5c) Parameter t CPdif has been specified in order that users may easily determine minimum CAS pulse widths when CASIN is togglingAUTOMATIC CAS GENERATIONCAS is held high when R C is high even if CASIN is low If CASIN is low when R C goes low CAS goes low automati-cally t ASC after the column address is valid This feature eliminates the need for an externally derived CASIN signal to control CAS when performing a simple access(Figure5a demonstrates Auto-CAS generation in mode4) Page or nib-ble accessing may be performed as shown in Figure5c even if CAS is generated automatically for the initial access FASTEST MEMORY ACCESSThe fastest Mode4access is achieved by using the auto-matic CAS feature and external delay line to generate the required delay between RASIN and R C The amount of delay required depends on the minimum t RAH of the DRAMs being used The DP8429parameter t DIF1has been speci-fied in order that the delay between RASIN and R C may be minimizedt DIF1e MAXIMUM(t RPDL-t RHA)where t RPDL e RASIN to RAS delayand t RHA e row address held from R C going low The delay between RASIN and R C that guarantees the specified DRAM t RAH is given byMINIMUM RASIN to R C e t DIF1a t RAH ExampleIn an application using DRAMs that require a minimum t RAH of15ns the following demonstrates how the maximum RASIN to CAS time is determined With t DIF1(from Switching Characteristics)e7ns RASIN to R C delay e7ns a15ns e22nsA delay line of25ns will be sufficientWith Auto-CAS generation the maximum delay from R C to CAS(loaded with600pF)is46ns Thus the maximum RASIN to CAS time is71ns under the given conditions With a maximum RASIN to RAS time(t RPDL)of20ns the maximum RAS to CAS time is about51ns Most DRAMs with a15ns minimum t RAH have a maximum t RCD of about 60ns Thus memory accesses are likely to be RAS limited instead of CAS limited In other words memory access time is limited by DRAM performance not controller perform-anceREFRESHING IN CONJUNCTION WITH MODE4If using mode4to access memory mode0(externally con-trolled refresh)must be used for all refreshingMODE5–AUTOMATIC ACCESS WITH HIDDEN RE-FRESHING CAPABILITYAutomatic-Access has two advantages over the externally controlled access(mode4) First RAS CAS and the row to column change are all derived internally from one input sig-nal RASIN Thus the need for an external delay line(see mode4)is eliminatedSecondly since R C and CASIN are not needed to gener-ate the row to column change and CAS these pins can be used for the automatic refreshing functionAUTOMATIC ACCESS CONTROLMode5of the DP8429makes accessing Dynamic RAM nearly as easy as accessing static RAM Once row and col-umn addresses are valid(latched on the DP8429if neces-sary) RASIN going low is all that is required to perform the memory accessTL F 8649–19FIGURE5c Page or Nibble Access in Mode412DP8428 DP8429Mode Descriptions (Continued)Indicates Dynamic RAM Parameters TL F 8649–20FIGURE 6 Mode 5Timing(Refer to Figure 6)In mode 5the selected RAS follows RASIN immediately as in mode 4 to strobe the row address into the DRAMs The row address remains valid on the DP8429address outputs long enough to meet the t RAH re-quirement of the DRAMs (pin 4 RAHS of the DP8429al-lows the user two choices of t RAH ) Next the column ad-dress replaces the row address on the address outputs and CAS goes low to strobe the columns into the DRAMs WIN determines whether a read write or read-modify-write is doneThe diagram below illustrates mode 5automatic control sig-nal generationTL F 8649–21REFRESHING IN CONJUNCTION WITH MODE 5When using mode 5to perform memory accesses refresh-ing may be accomplished(a)externally (in mode 0or mode 1)(b)by a combination of mode 5(hidden refresh)and mode 1(auto-refresh)or(c)by a combination of mode 5and mode 0(a)Externally Controlled Refreshing in Mode 0or Mode 1All refreshing may be accomplished using external refresh-es in either mode 0or mode 1with R C (RFCK)tied high (see mode 0and mode 1descriptions) If this is desired the system determines when a refresh will be performed puts the DP8429in the appropriate mode and controls the RAS signals directly with RASIN The on-chip refresh counter is enabled to the address outputs of the DP8429when the refresh mode is entered and increments when RASIN goes high at the completion of the refresh(b)Mode 5Refreshing (hidden)with Mode 1refreshing(auto)(Refer to Figure 7a )If RFCK is tied to a clock (see mode 1description) RFI O becomes a refresh request output and goes low following RFCK going low if no refresh occurred while RFCK was high Refreshes may be performed in mode 5when the DP8429is not selected for access (CS is high)and RFCK is high If these conditions exist the refresh counter contents appear on the DP8429address outputs and all RAS lines follow RASIN so that if RASIN goes low (an access other than through the DP8429occurs) all RAS lines go low to perform the refresh The DP8429allows only one refresh of this type for each period of RFCK since RFCK should be fast enough such that one refresh per peri-od is sufficient to meet the DRAM refresh requirement13DP8428 DP8429Mode Descriptions(Continued)Once it is started a hidden refresh will continue even if RFCK goes low However CS must be high throughout the refresh(until RASIN goes high)These hidden refreshes are valuable in that they do not delay accesses When determining the duty cycle of RFCK the high time should be maximized in order to maximize the probability of hidden refreshes If a hidden refresh doesn’t happen then a refresh request will occur on RFI O when RFCK goes low After receiving the request the system must perform a refresh while RFCK is low This may be done by going to mode1and allowing an automatic refresh (see mode1description) This refresh must be completed while RFCK is low thus the RFCK low time is determined by the worst-case time required by the system to respond to a refresh request(c)Mode5Refresh(Hidden Refresh)with mode0Refresh(External Refresh)This refresh scheme is identical to that in(b)except that after receiving a refresh request mode0is entered to do the refresh(see mode0description) The refresh request is terminated(RFI O goes high)as soon as mode0is en-tered This method requires more control than using mode1 (auto-refresh) however it may be desirable if the mode1 refresh time is considered to be excessiveExampleFigure7b demonstrates how a system designer would use the DP8429in mode5based on certain characteristics of his system System Characteristics1)DRAM used has min t RAH requirement of15ns andmin t ASR of0ns2)DRAM address is valid from time T V to the end of thememory cycle3)four banks of twenty-two256k memory chips each arebeing drivenUsing the DP8429(see Figure7b)1)Tie pin4(RAHS)high to guarantee a15ns minimumt RAH which is sufficient for the DRAMs being used2)Generate RASIN no earlier than time T V a t ASRL(seeswitching characteristics) so that the row address is valid on the DRAM address inputs before RAS occurs3)Tie ADS high since latching the DRAM address on theDP8429is not necessary4)Connect the first20system address bits to R0-R9andC0-C9 and bits21and22to B0and B15)Connect each RAS output of the DP8429to the RASinputs of the DRAMs of one bank of the memory array connect Q0-Q9of the DP8429to A0-A9of all DRAMs connect CAS of the DP8429to CAS of all the DRAMs Figure7c illustrates a similar example using the DP8428to drive two32-bit banksTL F 8649–22FIGURE7a Hidden Refreshing(Mode5)and Forced Refreshing(Mode1)Timing14。

高线性度
偏置Offset, 敏感度匹配 敏感度匹配Gain Mismatch, 前端内部线性补偿 (偏置 偏置 相位差补偿Orthogonality) 相位差补偿 后端多点调校线性度补偿
磁路
简单，可靠的磁路设计 简单， 既可安装于轴末端， 既可安装于轴末端，可以安装于轴上 磁铁价格低廉 各种材料 各种大小 环状， 。。。) 各种形状 (环状，条形，方形。。。 环状 条形，方形。。。
© Copyright Melexis Microelectronic Integrated Systems. All Rights Reserved
Tria⊗is™角度位置传感器 ⊗ ™ 位置传感器 MLX90316特性 特性
平面贴片 (SOIC-8 – TSSOP-16) 体积小 内部 DSP 冗余设计 (在TSSOP-16封装中有两枚芯片) 自我诊断能力 可替代其他传感器（互感，AMR, GMR…）
Throttle Position Sensor (TPS)
EMS ECU (Engine Management System Electronic Control Unit)
Actuator
踏板位置传感器（ ） 踏板位置传感器（PPS）
© Copyright Melexis Microelectronic Integrated Systems. All Rights Reserved
Motor
© Copyright Melexis Microelectronic Integrated Systems. All Rights Reserved
MCU
SPI
Position Sensor
e.g. MLX90316
Tria⊗is 摇杆位置传感器 ⊗ MLX90333

MP3解码芯片详解之Sigmatel –STMP3410，由于很多开发公司都从事这块芯片开发，因此目前能做的功能越来越多，包括电子图片，歌词同步，TXT阅读，闹钟等。

但由于它的部分程序放在flash上，因此容易出现丢程序现象。

sigmatel这个系列芯片的方案，目前应该是国内机器使用最多的。

最早为我们熟悉的MSC H128、爱国者月光宝盒，一直到现在，还有非常多的国产机器使用。

另一方面，韩国机器里使用该方案的代表产品有（列举的是国内品牌，实际原厂是韩国产品）：JNCSSF70、SSF800（3420芯片）、三星55（3420芯片）。

它的特点是目前开发程度较高——在开始时，该系列方案产品返修率高，现在的稳定性已经改善很多了。

而且国产产品里，用该芯片方案的比例应该是最大的。

先解释下芯片编号的意义：首先你要明确是哪个系列的：34XX系列的都是USB1.1，35XX才是USB2.0。

如果有JS说他的3410芯片支持USB2.0，别说偶没告诉你哦~！嘎嘎~~~其中34XX系列还有TA3、TA4之分，TA4较TA3的死机、漏码、丢失等现象改进不少。

（大家可以参考德劲DE-803的MP3，就是用2种芯片分2批生产的）35XX系列都是TA4的，大家可以放心购买。

再说下34XX和35XX的区别：省电、7彩背光、USB速度……而后面2位数字，应该是音质等效果，比如3501的音质就没3420的好。

偶个人觉得Sigmatel的录音确实是需要大大地改进了。

采用的是WAV波形格式，熟悉电脑的朋友肯定知道，这个是“无损录音”相当消耗内存空间，而闪存容量又小，128M的只能有大概8~12小时。

听音质，偶现在可以很肯定地听出来Sigmatel的风格了！Sigmatel给人的感觉……，呵呵，说不清楚，你自己听过就知道了~~！因为是单芯片设计，所以兼容性好，但是效能却没双芯片互补的好~但是经济嘛！偶手头的资料，大概就这么多了，以后有了还会继续增加！网友山海梦龙：SIGMATEL的芯片，开始时我觉得确实是便宜没好货：返修高、音质差、电流声、声音小……，但随着各厂商开发程度的深入，返修率逐渐低了下来，在音质表现上，也出现了象IAUDIO4（JNCSSF-800）这样化腐朽为神奇的代表产品。