SGM3141B
700mA Buck/Boost
Charge Pump LED Driver
GENERAL DESCRIPTION
The SGM3141B is a current-regulated charge pump
ideal for powering high brightness LEDs for camera
flash applications. The charge pump can be set to
regulate two current levels for Flash and Torch modes.
The
SGM3141B
automatically
switches
modes
FEATURES
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Output Current Up to 700mA
Up to 90% Efficiency in Torch Mode
Adjustable Flash Mode Current
1× and 2× Automatic Modes for High Efficiency
Input Voltage Range: 2.7V to 5.5V
Minimum External Components: No Inductors
High Frequency Operation: 2.2MHz
Low 47mV Reference for Low Loss Sensing
I
Q
< 1μA in Shutdown
Built-In Soft-Start Limits Inrush Current
Low Input and Output Ripple and Low EMI
Output Over-Voltage Protection
Over-Current and Over-Temperature Protection
Available in Green TDFN-3×3-10L Package
between step-up and step-down ensuring that LED
current does not depend on the forward voltage. It
switches at 2.2MHz, allowing the use of tiny
components. The supply voltage ranges from 2.7V to
5.5V and is ideally suited for all applications powered
by a single Li-ion battery cell or three to four NiCd,
NiMH, or Alkaline battery cells.
The SGM3141B also features a very low shutdown
current, an automatic soft-start mode to limit inrush
current, as well as over-current, over-voltage and
over-temperature thermal shutdown control.
A low current-sense reference voltage (47mV) allows
the use of small 0603 current sensing resistors.
The SGM3141B is available in Green TDFN-3×3-10L
package and is specified over an ambient temperature
range of -40℃ to +85℃.
TYPICAL APPLICATION
V
IN
2.7V to 5.5V
C
IN
4.7μF
C
F
1μF
1
VIN
C1
VOUT
10
9
C
OUT
1μF
WLED
8
7
6
R
SET
86.6kΩ
R
SENSE
0.22Ω
2
PGND
3
4
SGM3141B
C2
FLASH
EN
SGND
FB
RSET
TORCH/FLASH
ENABLE
5
APPLICATIONS
White LED Torch, Flash for Cell
Phones, DSCs and Camcorders
White LED Backlighting
Generic Lighting, Flash and Strobe Applications
General Purpose High Current Boost
SG Micro Corp
www.sg-micro.com
REV. A
SGM3141B
PACKAGE/ORDERING INFORMATION
MODEL
ORDER NUMBER
PACKAGE
DESCRIPTION
TDFN-3×3-10L
SPECIFIED
TEMPERATURE
RANGE
-40℃ to +85℃
700mA Buck/Boost
Charge Pump LED Driver
MARKING
INFORMATION
SGM
3141BD
XXXXX
PACKAGE
OPTION
Tape and Reel, 3000
SGM3141B
SGM3141BYD10G/TR
NOTE:
XXXXX
= Date Code and Vendor Code.
ABSOLUTE MAXIMUM RATINGS
V
IN
, V
OUT
, C2….……………………………..….…….-0.3V to 6V
EN, C1, FLASH, FB, RSET Pins
….………………………..………………..…...-0.3V to V
IN
+0.3V
Output Current Pulse (Flash)...............................................1A
Output Current Continuous (Torch)...................................0.4A
Package Thermal Resistance
TDFN-3×3-10L,
θ
JA
………………….………..…….……57℃/W
Storage Temperature Range……………........-40℃ to +150℃
Junction Temperature...………….………..….…………...150℃
Operating Temperature Range….…...…………-40℃ to +85℃
Lead Temperature (Soldering 10 sec)
…………………………..………..…………..……….……..260℃
ESD Susceptibility
HBM (EN Pin)……………………….……………..………1000V
HBM (All Other Pins) ………………….…………………..2000V
MM…………………………………………..………..………200V
CAUTION
This integrated circuit can be damaged by ESD if you don’t
pay attention to ESD protection. SGMICRO recommends that
all integrated circuits be handled with appropriate precautions.
Failure to observe proper handling and installation
procedures can cause damage. ESD damage can range from
subtle performance degradation to complete device failure.
Precision integrated circuits may be more susceptible to
damage because very small parametric changes could cause
the device not to meet its published specifications.
SGMICRO reserves the right to make any change in circuit
design, specification or other related things if necessary
without notice at any time. Please contact SGMICRO sales
office to get the latest datasheet.
NOTE:
Stresses beyond those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device. These
are stress ratings only, and functional operation of the device
at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for
extended periods may affect device reliability.
SG Micro Corp
www.sg-micro.com
2
SGM3141B
PIN CONFIGURATION
(TOP VIEW)
VIN
C1
C2
FLASH
EN
1
2
3
4
5
TDFN-3×3-10L
700mA Buck/Boost
Charge Pump LED Driver
10 VOUT
9
PGND
SGND
FB
RSET
GND
8
7
6
PIN DESCRIPTION
PIN
1
2
3
NAME
VIN
C1
C2
FUNCTION
Input Voltage for the Charge Pump. Decouple with 4.7μF or 10μF ceramic capacitor close to
the pins of the IC.
Positive Input for the External Flying Capacitor. Connect a ceramic 1μF capacitor close to
the pins of the IC.
Negative Input for the External Flying Capacitor. Connect a ceramic 1μF capacitor close to
the pins of the IC.
Logic Input to Toggle Operation between Flash and Torch Mode. In Torch mode FB is
regulated to the internal 47mV reference. In Flash mode FB reference voltage can be
adjusted by changing the resistor from RSET pin to ground. Choose the external current
sense resistor (R
SENSE
) based on desired current in Torch mode and Flash mode.
Shutdown Control Input. Connect to VIN for normal operation. Connect to ground for
shutdown. For normal operation, suggest to connect to VIN only after the VIN has settled if
the VIN ramping up is slow.
RSET Pin. Connect a resistor from this pin to ground. When in Flash mode (FLASH = High)
this resistor sets the current regulation point according to the following:
V
FB
= (1.26V/R
SET
) × 10.2kΩ.
Feedback Input for the Current Control Loop. Connect directly to the current sense resistor.
Internal Ground Pin. Control circuitry returns current to this pin.
Power Ground Pin. Flying capacitor current returns through this pin.
Charge Pump Output Voltage. Decouple with an external capacitor. At least 1μF is
recommended. If higher value capacitor is used, output ripple is smaller.
Exposed pad should be soldered to PCB board and connected to GND.
4
FLASH
5
EN
6
7
8
9
10
Exposed
Pad
RSET
FB
SGND
PGND
VOUT
GND
SG Micro Corp
www.sg-micro.com
3
SGM3141B
700mA Buck/Boost
Charge Pump LED Driver
ELECTRICAL CHARACTERISTICS
(Full = -40℃ to +85℃, V
IN
= 3.6V, C
IN
= 4.7μF, C
OUT
= C
F
= 1μF, V
SHDN
= V
IN
, typical values at +25℃, unless otherwise noted.)
PARAMETER
Input Supply Voltage
Quiescent Current
Shutdown Current
Oscillator Frequency
Charge Pump Equivalent
Resistance (2× mode)
Charge Pump Equivalent
Resistance (1× mode)
FB Reference Voltage
FB Pin Current
EN, FLASH Logic Low
EN, FLASH Logic High
EN, FLASH Pin Current
V
OUT
Turn-On Time
Thermal Shutdown Temperature
V
IN
= 3.6V, FB within 90% of regulation
V
FB
FLASH = V
IN
, R
SET
= 86.6kΩ
FLASH = GND
V
FB
= 0.3V
Full
Full
Full
250
145
1.3
1
Full
Full
131
38
SYMBOL
V
IN
I
Q
I
SHDN
V
IN
= 2.7V to 5.5V, FLASH = 0V,
I
LOAD
= 100μA
FLASH = V
IN
, 2× Mode
V
EN
= 0V, V
IN
= 5.5V
2.2
5
0.6
150
47
0.8
165
54
1
0.4
CONDITIONS
TEMP
Full
Full
MIN
2.7
0.3
2
1
μA
MHz
Ω
Ω
mV
μA
V
V
μA
μs
℃
TYP
MAX
5.5
3
UNITS
V
mA
SG Micro Corp
www.sg-micro.com
4
SGM3141B
C
IN
= 10μF, C
OUT
= 4.7μF, C
F
= 1μF, unless otherwise noted.
700mA Buck/Boost
Charge Pump LED Driver
TYPICAL PERFORMANCE CHARACTERISTICS
SG Micro Corp
www.sg-micro.com
5
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