LM2731
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GND
R3 51K
C1 2.2PF
L1/6.8PH
D1 MBR0520
VIN U1 SW
LM2731 ³<´
FB SHDN
GND
R1/117K
12V OUT 230mA (TYP)
R2
CF
13.3K 270pF
C2 10PF
EFFICIENCY (%)
Efficiency vs Load Current
The LM2731 switching regulators are current-mode boost converters operating at fixed frequencies of 1.6 MHz (“X” option) and 600 kHz (“Y” option).
The use of SOT-23 package, made possible by the minimal power loss of the internal 1.8A switch, and use of small inductors and capacitors result in the industry's highest power density. The 22V internal switch makes these solutions perfect for boosting to voltages up to 20V.
These parts have a logic-level shutdown pin that can be used to reduce quiescent current and extend battery life.
Protection is provided through cycle-by-cycle current limiting and thermal shutdown. Internal compensation simplifies design and reduces component count.
Human Body Model
−65°C to +150°C −40°C to +125°C
300°C Internally Limited
−0.4V to +6V −0.4V to +22V −0.4V to +14.5V −0.4V to VIN + 0.3V
265°C/W 2 kV
(1) Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the device outside of the limits set forth under the operating ratings which specify the intended range of operating conditions.
Connection Diagram
Figure 1. White LED Flash Application Top View
Figure 2. 5-Lead SOT-23 Package See Package Number DBV0005A
2
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R2 13.3K
D1
9V OUT
MBR0520 240mA (typ)
R1/84K D2
D3
CF
C2
330pF 4.7PF
R4
D4 D5 R5
B1 LI-ION 3.3 - 4.2V
L1 / 1.5 PH
0
FLASH
ENABLE
+-
R3 51K
C1 4.7PF
VIN
SW
LM2731"Y"
SHDN
FB
APPLICATIONS
• White LED Current Source • PDA’s and Palm-Top Computers • Digital Cameras • Portable Phones and Games • Local Boost Regulator
DESCRIPTION
Table 1. Switch Frequency
X 1.6 MHz
Y 0.6 MHz
Typical Application Circuit
5 VIN SHDN
GND
R3 51K
C1 2.2PF
L1/10PH
VIN U1 SW
LM2731 ³;´
SHDN
FB
GND
R2 13.3K
D1 MBR0520
GND
R2 120
EFFICIENCY (%)
Efficiency vs Load Current
100
90 80
70 60
50 40
30 20
10 0 0
3.3 -9V ^y_ s Υ]}v
50 100 150 200 250 300 LOAD (mA)
D1 MBR0520
WHITE
LED's C2 4.7PF
3.3 -5V Boost ^z_ s Υ]}v 90
80
70 0 200 400 600 800 LOAD CURRENT (mA)
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners.
Copyright © 2004–2012, Texas Instruments Incorporated
LM2731
TI Confidential - NDA Restrictions
SNVS217F – MAY 2004 – REVISED NOVEMBER 2012
3.3 VIN SHDN
100 90 80 70 60 50 40 30 20 10 0 0
3.3 -12V Boost ^z_ s Υ]}v
50 100 150 200 250
LOAD (mA)
3.3 VIN SHDN
GND
R3 51K
C1 2.2PF
L1/10PH
VIN U1 SW
LM2731 ³;´
SHDN
FB
GND
TI Confidential - NDA Restrictions
LM2731
SNVS217F – MAY 2004 – REVISED NOVEMBER 2012
LM2731 0.6/1.6 MHz Boost Converters With 22V Internal FET Switch in SOT-23
2
PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.
R1/117K
CF 220pF
12V OUT 500mA (TYP)
C2 4.7PF
EFFICIENCY (%)
Efficiency vs Load Current 100
5 - 12V Boost ^y_ s Υ]}v 90
80
70 0 100 200 300 400 500 LOAD CURRENT (mA)
3.3 VIN SHDN
GND
R3 51K
C1 2.2PF
L1/6.8PH
VIN U1 SW
LM2731 ³<´
SHDN
FB
GND
R2 13.3K
D1 MBR0520
R1/40.5K
CF 470pF
5V OUT 700mA (TYP)
C2 22PF
EFFICIENCY (%)
Efficiency vs Load Current 100
Product Folder Links: LM2731
Copyright © 2004–2012, Texas Instruments Incorporated
TI Confidential - NDA Restrictions
LM2731
Pin 1 2 3 4 5
Name SW GND FB
Absolute Maximum Ratings(1)
Storage Temperature Range Operating Junction Temperature Range Lead Temp. (Soldering, 5 sec.) Power Dissipation(2) FB Pin Voltage SW Pin Voltage Input Supply Voltage SHDN Pin Voltage θJA (SOT23-5) ESD Rating(3)
R3 51K
C1 2.2PF
L1/6.8PH
D1 MBR0520
VIN U1 SW
LM2731 ³<´
FB SHDN
GND
R1/117K
12V OUT 230mA (TYP)
R2
CF
13.3K 270pF
C2 10PF
EFFICIENCY (%)
Efficiency vs Load Current
The LM2731 switching regulators are current-mode boost converters operating at fixed frequencies of 1.6 MHz (“X” option) and 600 kHz (“Y” option).
The use of SOT-23 package, made possible by the minimal power loss of the internal 1.8A switch, and use of small inductors and capacitors result in the industry's highest power density. The 22V internal switch makes these solutions perfect for boosting to voltages up to 20V.
These parts have a logic-level shutdown pin that can be used to reduce quiescent current and extend battery life.
Protection is provided through cycle-by-cycle current limiting and thermal shutdown. Internal compensation simplifies design and reduces component count.
Human Body Model
−65°C to +150°C −40°C to +125°C
300°C Internally Limited
−0.4V to +6V −0.4V to +22V −0.4V to +14.5V −0.4V to VIN + 0.3V
265°C/W 2 kV
(1) Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the device outside of the limits set forth under the operating ratings which specify the intended range of operating conditions.
Connection Diagram
Figure 1. White LED Flash Application Top View
Figure 2. 5-Lead SOT-23 Package See Package Number DBV0005A
2
Submit Documentation Feedback
R2 13.3K
D1
9V OUT
MBR0520 240mA (typ)
R1/84K D2
D3
CF
C2
330pF 4.7PF
R4
D4 D5 R5
B1 LI-ION 3.3 - 4.2V
L1 / 1.5 PH
0
FLASH
ENABLE
+-
R3 51K
C1 4.7PF
VIN
SW
LM2731"Y"
SHDN
FB
APPLICATIONS
• White LED Current Source • PDA’s and Palm-Top Computers • Digital Cameras • Portable Phones and Games • Local Boost Regulator
DESCRIPTION
Table 1. Switch Frequency
X 1.6 MHz
Y 0.6 MHz
Typical Application Circuit
5 VIN SHDN
GND
R3 51K
C1 2.2PF
L1/10PH
VIN U1 SW
LM2731 ³;´
SHDN
FB
GND
R2 13.3K
D1 MBR0520
GND
R2 120
EFFICIENCY (%)
Efficiency vs Load Current
100
90 80
70 60
50 40
30 20
10 0 0
3.3 -9V ^y_ s Υ]}v
50 100 150 200 250 300 LOAD (mA)
D1 MBR0520
WHITE
LED's C2 4.7PF
3.3 -5V Boost ^z_ s Υ]}v 90
80
70 0 200 400 600 800 LOAD CURRENT (mA)
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners.
Copyright © 2004–2012, Texas Instruments Incorporated
LM2731
TI Confidential - NDA Restrictions
SNVS217F – MAY 2004 – REVISED NOVEMBER 2012
3.3 VIN SHDN
100 90 80 70 60 50 40 30 20 10 0 0
3.3 -12V Boost ^z_ s Υ]}v
50 100 150 200 250
LOAD (mA)
3.3 VIN SHDN
GND
R3 51K
C1 2.2PF
L1/10PH
VIN U1 SW
LM2731 ³;´
SHDN
FB
GND
TI Confidential - NDA Restrictions
LM2731
SNVS217F – MAY 2004 – REVISED NOVEMBER 2012
LM2731 0.6/1.6 MHz Boost Converters With 22V Internal FET Switch in SOT-23
2
PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.
R1/117K
CF 220pF
12V OUT 500mA (TYP)
C2 4.7PF
EFFICIENCY (%)
Efficiency vs Load Current 100
5 - 12V Boost ^y_ s Υ]}v 90
80
70 0 100 200 300 400 500 LOAD CURRENT (mA)
3.3 VIN SHDN
GND
R3 51K
C1 2.2PF
L1/6.8PH
VIN U1 SW
LM2731 ³<´
SHDN
FB
GND
R2 13.3K
D1 MBR0520
R1/40.5K
CF 470pF
5V OUT 700mA (TYP)
C2 22PF
EFFICIENCY (%)
Efficiency vs Load Current 100
Product Folder Links: LM2731
Copyright © 2004–2012, Texas Instruments Incorporated
TI Confidential - NDA Restrictions
LM2731
Pin 1 2 3 4 5
Name SW GND FB
Absolute Maximum Ratings(1)
Storage Temperature Range Operating Junction Temperature Range Lead Temp. (Soldering, 5 sec.) Power Dissipation(2) FB Pin Voltage SW Pin Voltage Input Supply Voltage SHDN Pin Voltage θJA (SOT23-5) ESD Rating(3)
