ZXCD1000中文资料(Zetex Semiconductors)中文数据手册「EasyDatasheet - 矽搜」

ZXCT1080High voltage high-side current monitorDescriptionOrdering informationThe ZXCT1080 is a high side current sense monitor with a gain of 10 and a voltage output. Using this device eliminates the need to disrupt the ground plane when sensing a load current.The wide input voltage range of 60V down to as low as 3V make it suitable for a range of applications; including systems operating from industrial 24-28V rails and -48V rails.The separate supply pin (V CC ) allows the device to continue functioning under short circuit conditions, giving an end stop voltage at the output.The ZXCT1080 has an extended ambient operating temperature range of -40°C to 125°C enabling it to be used in a wide range of applications including automotive.Features•3V to 60V continuous high side voltage •Accurate high-side current sensing •-40 to 125°C temperature range •Output voltage scaling x10• 4.5V to 12V V CC range •Low quiescent current:•70µA supply pin •50µA I SENSE+•SOT23-5 package Applications•Industrial applications current measurement •Battery management •Over current monitor •Power management•Automotive current measurementPin connectionsTypical application circuitDevicePackage Part mark Reel size (inches)Tape width (mm)Quantity perreelZXCT1080E5TASOT23-51080783000https://Absolute maximum ratingsContinuous voltage on S- and S+-0.6 and 65V Voltage on all other pins-0.6V and +14VDifferential sense voltage, V SENSE 800mV Operating temperature -40 to 125°C Storage temperature-55 to 150°C Maximum junction temperature 125°CPackage power dissipation300mW * at T A = 25°COperation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for extended periods, may reduce device reliability.V SENSE is defined as the differential voltage between S+ and S- pins.*Assumes ⍜JA = 420°C/WRecommended operating conditionsPin function tableParameterMin.Max.Units V IN Common-mode sense+ input range 360V V CCSupply voltage range4.512V V SENSE Differential sense input voltage range 00.15V V OUT Output voltage range 0 1.5V T AAmbient temperature range-40125°CPin Name Description1V CC This is the analogue supply and provides power to internal circuitry 2GND Ground pin3OUT Output voltage pin. NMOS source follower with 20µA bias to ground 4S+This is the positive input of the current monitor and has an input range from 60V down to 3V. The current through this pin varies with differential sense voltage5S-This is the negative input of the current monitor and has an input range from 60V down to 3Vhttps://Electrical characteristicsTest conditions T A = 25°C, V IN = 12V, V CC = 5 V, V SENSE (a) = 100mV unless otherwise stated.NOTES:(a)V SENSE = "V SENSE+" - "V SENSE-"(b)The ZXCT1080 operates from a positive power rail and the internal voltage-current converter current flow is unidirectional; these result in the output offset voltage for V SENSE = 0V always being positive.(c)For V SENSE > 10mV, the internal voltage-current converter is fully linear. This enables a true offset to be defined and used. V O(10) is expressed as the variance about an output voltage of 100mV>(d)Temperature dependent measurements are extracted from characterization and simulation results.(e)All Min and Max specifications over full temperature range are guaranteed by design and characterisationSymbol ParameterConditions T A Min (e).Typ.Max (e).Units I CC V CC supply current V CC = 12V, V SENSE (a) = 0V 25°C 4080120µAfull range 145I S+S+ input current V SENSE (a) = 0V25°C 152742µA full range 60I S-S- input current25°C 154080nA V O(0)Zero V SENSE (a) error (b)25°C 035mV V O(10)Output offset voltage (c)V SENSE (a) = 10mV 25°C -25+25mV full range -55+55Gain⌬V OUT /⌬V SENSE (a)V SENSE (a) = 10mV to150mV 25°C 9.91010.1V/V full range9.810.2V OUT TC (d)V OUT variation withtemperature 30ppm/°C Acc Total output error -33%I OH Output source current⌬V OUT = -30mV 1mA I OL Output sink current⌬V OUT = +30mV20µA PSRR V CC supply rejection ratioV CC = 4.5V to 12V 5460dB CMRR Common-mode sense rejection ratio V IN = 60V to 3V 6880dB BW-3dB small signal bandwidthV SENSE (a) (AC) = 10mV PP500kHz https://Typical characteristicsTest conditions unless otherwise stated: T A = 25°C, V CC = 5V, V SENSE+ =12V, V SENSE = 100mVTypical characteristicsTest conditions unless otherwise stated: T A = 25°C, V CC = 5V, V SENSE+ =12V, V SENSE = 100mVTypical characteristicsTest conditions unless otherwise stated: T A = 25°C, V CC = 5V, V SENSE+ =12V, V SENSE = 100mVhttps://Application informationThe ZXCT1080 has been designed to allow it to operate with 5V supply rails while sensing common mode signals up to 60V. This makes it well suited to a wide range of industrial and power supply monitoring applications that require the interface to 5V systems while sensing much higher voltages.To allow this its V CC pin can be used independently of S+.Figure 1 shows the basic configuration of the ZXCT1080.Figure 1Typical configuration of ZXCT1080Load current from the input is drawn through R SENSE developing a voltage V SENSE across the inputs of the ZXCT1080.The internal amplifier forces V SENSE across internal resistance R GT causing a current to flow through MOSFET M1. This current is then converted to a voltage by R G . A ratio of 10:1 between R G and R GT creates the fixed gain of 10. The output is then buffered by the unity gain buffer.The gain equation of the ZXCT1080 is:The maximum recommended differential input voltage, V SENSE , is 150mV; it will howeverwithstand voltages up to 800m ⍀. This can be increased further by the inclusion of a resistor, R LIM ,between S- pin and the load; typical value is of the order of 10k .V OUT I L R SENSE R GRGT---------1×I L R SENSE ×10×==https://Figure 2Protection/error sources for ZXCT1080Capacitor C D provides high frequency transient decoupling when used with R LIM ; typical values are of the order 10pFFor best performance R SENSE should be connected as close to the S+ (and SE NSE ) pins;minimizing any series resistance with R SENSE .When choosing appropriate values for R SENSE a compromise must be reached between in-line signal loss (including potential power dissipation effects) and small signal accuracy.Higher values for R SENSE gives better accuracy at low load currents by reducing the inaccuracies due to internal offsets. For best operation the ZXCT1080 has been designed to operate with V SENSE of the order of 50mV to 150mV.Current monitors' basic configuration is that of a unipolar voltage to current to voltage converter powered from a single supply rail. The internal amplifier at the heart of the current monitor may well have a bipolar offset voltage but the output cannot go negative; this results in current monitors saturating at very low sense voltages.As a result of this phenomenon the ZXCT1080 has been specified to operate in a linear manner over a V SENSE range of 10mV to 150mV range, however it will still be monotonic down to VSENSE of 0V.It is for this very reason that Zetex has specified an input offset voltage (V O(10)) at 10mV. The output voltage for any V SENSE voltage from 10mV to 150mV can be calculated as follows:Alternatively the load current can be expressed as:V OUT V SENSE ()xG V O 10()+=I L V OUT V O 10()–()GxR SENSE------------------------------------------=https://Package details - SOT23-5Note: Controlling dimensions are in millimeters. Approximate dimensions are provided in inchesDIM MillimetersInchesMin.Max.Min.Max.A - 1.00-0.0393A10.010.100.00030.0039A20.840.900.03300.0354b 0.300.450.01180.0177c 0.120.200.00470.0078D 2.90 BSC 0.114 BSCE 2.80 BSC 0.110 BSC E1 1.60 BSC 0.062 BSC e 0.95 BSC 0.0374 BSC e1 1.90 BSC0.0748 BSCL 0.300.500.01180.0196L20.25 BSC 0.010 BSC a°4°12°4°12°https://ZXCT1080DefinitionsProduct changeZetex Semiconductors reserves the right to alter, without notice, specifications, design, price or conditions of supply of any product or service. Customers are solely responsible for obtaining the latest relevant information before placing orders.Applications disclaimerThe circuits in this design/application note are offered as design ideas. It is the responsibility of the user to ensure that the circuit is fit for the user’s application and meets with the user’s requirements. No representation or warranty is given and no liability whatsoever is assumed by Zetex with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Zetex does not assume any legal responsibility or will not be held legally liable (whether in contract,tort (including negligence), breach of statutory duty, restriction or otherwise) for any damages, loss of profit, business, contract,opportunity or consequential loss in the use of these circuit applications, under any circumstances.Life supportZetex products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Zetex Semiconductors plc. As used herein:A. Life support devices or systems are devices or systems which:1.are intended to implant into the bodyor 2.support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in thelabelling can be reasonably expected to result in significant injury to the user.B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected tocause the failure of the life support device or to affect its safety or effectiveness.ReproductionThe product specifications contained in this publication are issued to provide outline information only which (unless agreed by the company in writing) may not be used, applied or reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned.Terms and ConditionsAll products are sold subjects to Zetex’ terms and conditions of sale, and this disclaimer (save in the event of a conflict between the two when the terms of the contract shall prevail) according to region, supplied at the time of order acknowledgement.For the latest information on technology, delivery terms and conditions and prices, please contact your nearest Zetex sales office.Quality of productZetex is an ISO 9001 and TS16949 certified semiconductor manufacturer.To ensure quality of service and products we strongly advise the purchase of parts directly from Zetex Semiconductors or one of our regionally authorized distributors. For a complete listing of authorized distributors please visit: /salesnetworkZetex Semiconductors does not warrant or accept any liability whatsoever in respect of any parts purchased through unauthorized sales channels.ESD (Electrostatic discharge)Semiconductor devices are susceptible to damage by ESD. Suitable precautions should be taken when handling and transporting devices.The possible damage to devices depends on the circumstances of the handling and transporting, and the nature of the device. The extent of damage can vary from immediate functional or parametric malfunction to degradation of function or performance in use over time.Devices suspected of being affected should be replaced.Green complianceZetex Semiconductors is committed to environmental excellence in all aspects of its operations which includes meeting or exceeding regulatory requirements with respect to the use of hazardous substances. Numerous successful programs have been implemented to reduce the use of hazardous substances and/or emissions.All Zetex components are compliant with the RoHS directive, and through this it is supporting its customers in their compliance with WEEE and ELV directives.Product status key:“Preview”Future device intended for production at some point. Samples may be available“Active”Product status recommended for new designs“Last time buy (LTB)”Device will be discontinued and last time buy period and delivery is in effect“Not recommended for new designs”Device is still in production to support existing designs and production“Obsolete”Production has been discontinuedDatasheet status key:“Draft version”This term denotes a very early datasheet version and contains highly provisional information, which may change in any manner without notice.“Provisional version”This term denotes a pre-release datasheet. It provides a clear indication of anticipated performance.However, changes to the test conditions and specifications may occur, at any time and without notice.“Issue”This term denotes an issued datasheet containing finalized specifications. However, changes tospecifications may occur, at any time and without notice.https://。

1S E M I C O N D U C T O R SDESCRIPTIONThe ZXLD1100is a PFM inductive boost converter designed for driving 2,3or 4series connected white LEDs from a Li-Ion cell and up to 8LEDs from a 5V supply.The device operates from an input supply of between 2.5V and 5.5V and provides an adjustable output current of up to 50mA.The ZXLD1100includes the output switch and peak current sense resistor,and can operate with a maximum output voltage of 28V.Quiescent current is typically 60␮A and a shutdown function is provided to reduce this current to less than 500nA in the 'off' state.ADVANCED FEATURES•Internal 30V NDMOS switch, current sense andopen circuit protection•True Analog Dimming via PWMFEATURES•Low profile SC70 6 pin package•Internal PWM filter for flicker free output •High efficiency (80% typ)•Wide input voltage range: 2.5V to 5.5V •Up to 50mA output current•Low quiescent current: (60␮A typ)•500nA maximum shutdown current •Up to 1MHz switching frequency •Low external component count •Inherently matched LED currentsOutput current can be adjusted by applying a PWM control signal to the 'Enable'pin.Depending upon the control frequency,this will provide either a continuous or a 'chopped'output current.The PWM filter components are contained within the chip.The ZXLD1100contains an internal avalanche diode to protect the output switch.This allows the device to operate indefinitely if the load is open circuit.Input supply current during this condition is less than 1mA.The device is assembled in a low profile SC70-6pin package with industry standard pinout.APPLICATIONS•Mobile phones •Digital cameras •PDAs •LCD modules•Portable internet appliances •Palmtop computersZXLD1100ISSUE 4 - JULY 2004ADJUSTABLE LED DRIVER WITH INTERNAL SWITCH AND OPENCIRCUIT PROTECTION IN SC70-6PIN CONNECTIONSTYPICAL APPLICATION CIRCUITZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 20042PARAMETER SYMBOL LIMIT UNIT Input voltage (V IN )7V LX output voltage (V LX )30V Switch output current (I LX )500mA Power dissipation (PD)300mW Operating temperature (T OP )-40 to 85°C Storage temperature (T ST )-55 to 150°C Junction temperature(T j MAX )125°CABSOLUTE MAXIMUM RATINGS (Voltages to GND unless otherwise stated)DEVICE DEVICE DESCRIPTION TEMPERATURE RANGEPART MARKTAPING OPTIONS ZXLD1100H6Boost convertor in SC70-6-40 to +85°C110TA, TCORDERING INFORMATIONZXLD1100H6TA = 7” reel of 3,000 devices ZXLD1100H6TC = 13” reel of 10,000 devicesZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 20043SYMBOL PARAMETER CONDITIONSMIN.TYP .MAX.UNIT V IN Input voltage 2.55.5VI INSupply currentQuiescent ShutdownV EN =V IN ,I LX =0,Output not switching V EN =0V60100500␮A nA V FB FB pin control voltage 90.5109.5mV I FB FB pin input current 100nA f LX Operating frequency L=10␮H,V OUT =10V,I OUT =20mA0.351MHz T OFF LX output 'OFF'time 350500ns T ON LX output 'ON'time (2)5µs I LXpk Switch peak current limit L=10␮H,V OUT =10V,I OUT =20mA320mA R LX Switch 'On'resistance 1.5⍀I LX(leak)Switch leakage current V LX =20V1µA V OUTController output voltageNormal operation VSENSE pin open-circuit or grounded28VV OUT(MAX)Controller output voltage with outputopen circuit (3)VSENSE connected to Vout2530V V ENH EN pin High level Input voltage Device active 1.5V IN V V ENL EN pin Low level Input voltage Device in shutdown 0.4V I ENL EN pin Low level input current V EN =0V-100nA I ENH EN pin High level input current V EN =V IN1␮A T EN(hold)EN pin turn off delay(4)V EN switched from high to low120µs ∆T/T PWM duty cycle range at ‘EN’input for filtered PWM control (5)10kHz <f <100kHz,V ENH =V IN20100%f LPF Internal PWM low pass filter cut-off frequency 4kHz A LPFFilter attenuationf=30kHz52.5dBELECTRICAL CHARACTERISTICS (at V IN = 3V , T amb = 25°C unless otherwise stated (1))NOTES:(1) Production testing of the device is performed at 25°C. Functional operation of the device over a -40°C to +85°C temperature range is guaranteed by design, characterization and process control.(2) Nominal 'on' time (T ONnom ) is defined by the input voltage (V IN ), coil inductance (L) and peak current (I LXpkdc ) according to the expression:T ONnom = {I LX(pkdc ) x L/V IN } +200ns.(3) When using the open circuit protection feature, the maximum output voltage under normal operation should be maintained below the minimum value specified, in order to prevent possible disturbance of the current control loop.(4) This is the time for which the device remains active after the EN pin has been asserted low. This delay is necessary to allow the output to be maintained during dc PWM mode operation.(5)The minimum PWM signal frequency during this mode of operation is to ensure that the device remains active during PWM control. This provides a continuous dc output current. For lower frequencies, the device will be gated 'on' and 'off' during PWM control.(6)The maximum PWM signal frequency during this mode of operation should be kept as low as possible to minimize errors due to the turn-off delay of the device (see Enable pin turn-off delay).ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 20044BLOCK DIAGRAMPIN DESCRIPTIONDEVICE DESCRIPTIONThe device is a PFM flyback dc-dc boost converter, working in discontinuous mode.With reference to the chip block diagram and typical application circuit,the operation of the device is as follows:Control loopWhen'EN'is high,the control circuits become active and the low side of the coil(L1)is switched to ground via NDMOS transistor(MN).The current in L1is allowed to build up to an internally defined level (nominally320mA)before MN is turned off.The energy stored in L1is then transferred to the output capacitor (C2)via schottky diode(D1).When the voltage on C2 has risen above the threshold voltage of the series connected LEDs,current will flow through external sense resistor R1.The voltage developed across R1is sensed at pin'FB'and compared to a100mV reference voltage(V REF).A comparator senses when the feedback voltage is above V REF and its output is used to control the'off'time of the output switch.The control loop is self-oscillating,producing pulses of up to5␮s maximum duration(switch'on'),at a frequency that varies in proportion to the LED current.The feedback loop maintains a voltage of V REF at the FB pin and therefore defines a maximum LED current equal to V REF divided by R1.The minimum'off'time of the output switch is fixed at0.5␮s nominal,to allow time for the coil's energy to be dissipated before the switch is turned on again.This maintains stable and efficient operation in discontinuous mode.Open circuit protectionThere is an internal avalanche diode between the V SENSE and FB pins of the device.This diode,together with the associated resistors provides open circuit protection when the V SENSE pin is connected to the output voltage.In the event of an open circuit condition,the output voltage will rise above the breakdown voltage of the internal diode,which will then conduct and override the control signal from the current sense resistor.This maintains the output voltage at a level below the breakdown voltage of the output switch.Supply current in this condition will fall to a low value as the control loop provides only the bias current for the diode.Filtered PWM operationThe input of an internal low pass filter is switched to V REF when the EN pin is high and switched to ground when the EN pin is low.The output of this filter drives the comparator within the control loop.A continuous high state on EN therefore provides a filtered voltage of value V REF to the comparator.However,by varying the duty cycle of the EN signal at a suitably high frequency (f>10kHz),the control loop will see a voltage,that has an average value equal to the duty cycle multiplied by V REF.This provides a means of adjusting the output current to a lower value.It also allows the device to be both turned on and adjusted with a single signal at the 'EN'pin.The output during this mode of operation will be a dc current equal to (V REF/R1) x duty cycleGated PWM operationThe internal circuitry of the ZXLD1100is turned off when no signal is present on the'EN'pin for more than 120␮s(nominal).A low frequency signal applied to the EN pin will therefore gate the device'on'and'off'at the gating frequency and the duty cycle of this signal can be varied to provide a'chopped'output current equal to(V REF/R1)x duty cycle.For best accuracy,the gating frequency should be made as low as possible(e.g. below1kHz),such that the turn off delay of the chip is only a small proportion of the gating periodFurther details of setting output current are given in the applications section under brightness control.ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 20045ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 2004 6TYPICAL CHARACTERISTICS(For typical application circuit at V IN=3V and TA=25 °C unless otherwise stated)ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 20047TYPICAL OPERATING CHARACTERISTICS(For typical applications circuit at V IN =3V, L=10␮H Coilcraft DO1608C Series, 3 series LEDs,I=15mA, T =25 °C unless otherwise stated)APPLICATIONSProgramming the maximum LED currentThe maximum LED current is programmed by adding a single resistor in series with the LED chain.The current is determined by the resistor value and feedback voltage and is given by:I LED= V FB/R1where V FB=100mVThe table below gives recommended resistor values for required LED currents:Dimming Control via a PWM signal on the EN pinA Pulse Width Modulated(PWM)signal can be applied to the EN pin in order to adjust the output current to a value below the maximum LED current.Two modes of adjustment are possible as described below.True Analog Dimming - Filtered ‘DC’ modeIf a PWM signal of10kHz or higher is applied to the EN pin,the device will remain active when the EN pin is low.However,the input to the internal low pass filter will be switched alternately from V REF to ground,with a duty cycle(D)corresponding to that of the PWM signal. This will present a filtered dc voltage equal to the duty cycle multiplied by V REF to the control loop and will produce a dc output current lower than the maximum set value. This current is given by:I OUTdc= 0.1D/R1This mode of adjustment minimizes flicker in the light output and system noise.Pulsed Dimming - Gated ModeIf a lower frequency of1kHz or less is applied to the EN pin,the device will be gated‘on’and‘off’at a duty cycle (D)corresponding to that of the input signal.The average output current is then given by:I OUTavg»0.1D/R1This mode may be preferred over dc current control if the purest white output is required.However,note the 120␮s nominal turn-off delay of the device,when using the device in this mode.Dimming Control using a DC voltageFor applications where the EN pin is not available a DC voltage can be used to control dimming.By adding resistors R2and R3and applying a DC voltage,the LED current can be adjusted from100%to0%.As the DC voltage increases,the voltage drop across R2increases and the voltage drop across R1decreases,thus reducing the current through the LEDs.Selection of R2 and R3should ensure that the current from the DC voltage is much less than the LED current and much larger than the feedback current.The component values in the diagram below represent0%to100% dimming control from a 0 to 2V DC voltage.Dimming Control using a logic signalFor applications where the LED current needs to be adjusted in discrete steps a logic signal can be applied as shown in the diagram below.When Q1os‘off’,R1 sets the minimum LED current.When Q1is‘on’,R2sets the LED current that will be added to the minimum LED current.The formula for selecting values for R1and R2 are given below:MOSFET ‘off’IVRLED MINFBLED()MOSFET‘on’IVRILED MAXLEDLED MINFB()()where V FB= 100mVZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 20048Open circuit protectionThe voltage sense pin(V SENSE)can be connected to the output to provide open circuit protection for the device and external circuits when driving series connected LEDs,thus eliminating the need for an external Zener diode.Protection is provided by the internal avalanche diode(ZD),which limits the maximum output voltage to a value below the breakdown voltage of the output switch when the connection to the diodes is broken.Capacitor selectionA ceramic capacitor grounded close to the GND pin of the package is recommended at the output of the device.Surface mount types offer the best performance due to their lower inductance.A minimum value of0.22␮F is advised,although higher values will lower switching frequency and improve efficiency especially at lower load currents.A higher value will also minimize ripple when using the device to provide an adjustable dc output current.A good quality,low ESR capacitor should also be used for input decoupling,as the ESR of this capacitor is effectively in series with the source impedance and lowers overall efficiency.This capacitor has to supply the relatively high peak current to the coil and smooth the current ripple on the input supply.A minimum value of1␮F is acceptable if the input source is close to the device,but higher values will improve performance at lower input voltages,when the source impedance is high.The input capacitor should be mounted as close as possible to the IC For maximum stability over temperature,capacitors with X7R dielectric are recommended,as these have a much smaller temperature coefficient than other types.A table of recommended manufacturers is provided below:ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 20049Inductor selectionThe choice of inductor will depend on available board space as well as required performance.Small value inductors have the advantage of smaller physical size and may offer lower series resistance and higher saturation current compared to larger values.A disadvantage of lower inductor values is that they result in higher frequency switching,which in turn causes reduced efficiency due to switch losses.Higher inductor values can provide better performance at lower supply voltages.However,if the inductance is too high,the output power will be limited by the internal oscillator,which will prevent the coil current from reaching its peak value.This condition will arise whenever the ramp time (I LX(peak)x L/V IN )exceeds the nominal 5␮s maximum ‘on’time limit for the LX output.The graphs opposite show the ZXLD1100performance for given inductor values and different manufacturers.Recommended inductor values for the ZXLD1100are in the range 6.8␮H to 22␮H.The inductor should be mounted as close to the device as possible with low resistance connections to the LX and VIN pins.Suitable coils for use with the ZXLD1100are shown in the table below:Diode selectionThe rectifier diode (D1)should be a fast low capacitance schottky diode with low reverse leakage at the working voltage.It should also have a peak current rating above the peak coil current and a continuous current rating higher than the maximum output load current.The table below gives some typical characteristics for diodes that can be used with the ZXLD1100:(mA)I R at 30V (A)Package 15SOD32315SOT23Layout considerationsPCB tracks should be kept as short as possible to minimize ground bounce,and the ground pin of the device should be soldered directly to the ground plane.It is particularly important to mount the coil and the input/output capacitors close to the device to minimize parasitic resistance and inductance,which will degrade efficiency.The FB pin is a high impedance input so PCB track lengths to this should also be kept as short as possible to reduce noise pickup.Excess capacitancefrom the FB pin to ground should be avoided.ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 200410REFERENCE DESIGNS3LED Driver for Handset LCD BacklightZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 200411Circuit DiagramPerformance GraphsBill of materialsNote:R2 is optional. If EN is floating add R2 to shutdown the ZXLD1100 and LEDs. If EN pin can be driven low, R2 is not necessary.Note: LED current is set to 15mA4LED Driver for Handset LCD Backlight ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 200412Circuit DiagramPerformance GraphsBill of materialsNote:R2 is optional. If EN is floating add R2 to shutdown the ZXLD1100 and LEDs. If EN pin can be driven low, R2 is not necessary.Note: LED current is set to 15mA5LED Driver for Handset Main and Sub Display LCD Backlight ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 200413Circuit DiagramPerformance GraphsBill of materialsNote:R2 is optional. If EN is floating add R2 to shutdown the ZXLD1100 and LEDs. If EN pin can be driven low, R2 is not necessary.Note: LED current is set to 15mA6LED Driver for LCD Backlight ZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 200414Circuit DiagramPerformance GraphsBill of materialsNote:R2 is optional. If EN is floating add R2 to shutdown the ZXLD1100 and LEDs. If EN pin can be driven low, R2 is not necessary.Note: LED current is set to 15mAZXLD1100S E M I C O N D U C T O R SISSUE 4 - JULY 200415ZXLD1100S E M I C O N D U C T O R S16ISSUE 4 - JULY 2004EuropeZetex plcFields New Road ChaddertonOldham, OL9 8NP United KingdomTelephone (44) 161 622 4444Fax: (44) 161 622 4446hq@Zetex GmbHStreitfeldstraße 19D-81673 München GermanyTelefon: (49) 89 45 49 49 0Fax: (49) 89 45 49 49 49europe.sales@AmericasZetex Inc700 Veterans Memorial Hwy Hauppauge, NY 11788USATelephone: (1) 631 360 2222Fax: (1) 631 360 8222usa.sales@Asia PacificZetex (Asia) Ltd3701-04Metroplaza Tower 1Hing Fong Road Kwai Fong Hong KongTelephone: (852) 26100 611Fax: (852) 24250 494asia.sales@These offices are supported by agents and distributors in major countries world-wide.This publication is issued to provide outline information only which (unless agreed by the Company in writing)may not be used,applied or reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned.The Company reserves the right to alter without notice the specification,design,price or conditions of supply of any product or service.For the latest product information,log on to©Zetex plc 2003SCZXLD1100DS2DIM Millimeters Inches DIM Millimeters Inches Min Max Min Max MinMaxMinMaxA 0.80 1.100.03150.0433E 2.10BSC 0.0826 BSC A1-0.10-0.0039E1 1.251.350.04920.0531A20.80 1.000.03150.0394e 0.65 BSC 0.0255 BSC b 0.150.300.0060.0118e1 1.30 BSC 0.0511 BSC C 0.080.250.00310.0098L 0.260.460.01020.0181D2.00 BSC 0.0787 BSCa°0°8°0°8°PACKAGE DIMENSIONSControlling dimensions are in millimeters. Approximate conversions are given in inches。