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LTC3212 RGB LED Driver and Charge Pump FeaTures

DescripTion
The LTC(R)3212 is a low noise charge pump RGB LED driver capable of driving three LEDs up to 25mA each from a 2.7V to 5.5V input. Low external part count (one flying capacitor, two bypass capacitors and one to three programming resistors) makes the LTC3212 ideally suited for small, battery-powered applications. Built-in soft-start circuitry prevents excessive inrush current during start-up and mode switching. High switching frequency enables the use of small external capacitors. The charge pump shuts down to a high impedance mode to prevent LED leakage while the LTC3212 is off. Each LED may be individually turned on or off via a single pin interface. The current through the LEDs may be individually programmed with resistors or may share a single programming resistor. White mode adjusts the red, green and blue LED current ratios for a white light when all three LEDs are programmed to be on. LED currents are regulated using internal low dropout current sources. Automatic mode switching optimizes efficiency by monitoring the LED current drivers and switches mode only when dropout is detected. The part is available in a 3mm x 2mm 12-lead DFN package.

Power and Current Control for Driving RGB LEDs Individually Programmable Current Sources 1x or 2x Mode, Low Noise, Constant Frequency Charge Pump Single Wire Enable Control for All LEDs White Mode Adjusts R, G, B Currents for White Light 25mA Maximum LED Current VIN Range: 2.7V to 5.5V Automatic Soft-Start, Mode Switching and Output Disconnect in Shutdown Mode Available in 12-Lead (3mm x 2mm) DFN Package
applicaTions

Cellular Phones Media Players RGB Back Lights
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6411531.
Typical applicaTion
RGB Power Supply and Current Control
1F
VIN 2.7V TO 5.5V
CM VIN 1F LEDEN ISETB ISETR ISETG 11.8k
CP CPO R G B 1F
LTC3212 LEDR LEDG LEDB
INDIVIDUAL WHITE SETTINGS MODE LEDR LEDG LEDB 15mA 15mA 15mA 13.5mA 15mA 11.2mA
3212 TA01a
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LTC3212 absoluTe MaxiMuM raTinGs
(Note 1)
pin conFiGuraTion
TOP VIEW CP 1 CPO 2 LEDEN 3 ISETB 4 ISETR 5 ISETG 6 13 12 VIN 11 CM 10 GND 9 LEDB 8 LEDR 7 LEDG
VIN to GND ................................................... -0.3V to 6V CPO to GND ................................................. -0.3V to 6V LEDEN ............................................. -0.3V to VIN + 0.3V ICPO (Note 2) ..........................................................75mA ILED(R,G,B) (Note 2) .................................................30mA CPO Short-Circuit Duration .............................. Indefinite Operating Temperature Range (Notes 3, 4).......................................... -40C to 85C Storage Temperature Range................... -65C to 125C
DDB PACKAGE 12-LEAD (3mm x 2mm) PLASTIC DFN TJMAX = 125C, JA = 76C/W EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH LTC3212EDDB#PBF TAPE AND REEL LTC3212EDDB#TR PART MARKING LCWM PACKAGE DESCRIPTION 12-Lead (3mm x 2mm) Plastic DFN TEMPERATURE RANGE -40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
elecTrical characTerisTics
PARAMETER VIN Operating Voltage IVIN Operating Current VIN Shutdown Current LED Current Current Ratio (ILEDG/ISETG) Current Ratio (ILEDB/ISETB) Current Ratio (ILEDB/ISETG) Current Ratio (ILEDR/ISETR) Current Ratio (ILEDR/ISETG) ILED Dropout Voltage (VILED) tEN Mode Switching Delay Charge Pump (CPO) Charge Pump Output Voltage Clamp 1x Mode Output Impedance (Notes 6, 7)
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VIN = 3.6V.
CONDITIONS
MIN 2.7
TYP 0.4 2.0 3
MAX 5.5
UNITS V mA mA
ICPO = 0mA, 1x Mode ICPO = 0mA, 2x Mode LEDEN = Low ISETG = 78A ISETB = 78A White Mode, ISETG = 78A ISETR = 78A White Mode, ISETG = 78A Mode Switching Theshold, ILED = 15mA Current Source Enable Time (LEDEN = High) (Note 5)
8 210 210 160 210 186 400
A A/A A/A A/A A/A A/A mV s s V
173 173 128 173 154
192 192 144 192 171 150
50
120 5.1 5
250
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LTC3212 elecTrical characTerisTics
PARAMETER 2x Mode Output Impedance CLK Frequency LEDEN High Level Input Voltage (VIH) Low Level Input Voltage (VIL) Input Current (IIH) Input Current (IIL) tPWH tPWL tSD ISET(R,G,B) VISET IISET Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: Based on long-term current density limitations. Note 3: The LTC3212E is guaranteed to meet performance specifications from 0C to 85C. Specifications over the -40C to 85C ambient operating temperature range are assured by design, characterization and correlation with statistical process controls 864 925 985 140 mV A High Pulse Width Low Pulse Width Low Time to Shutdown (LEDEN = Low)

The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VIN = 3.6V.
CONDITIONS (Notes 6, 7) 650 1.4 0.4 3 -1 0.08 0.08 350 20 10 1 MIN TYP 25 900 1275 MAX UNITS kHz V V A A s s s
LEDEN = 3.6V
Note 4: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. Note 5: If the LTC3212 has been shut down, then the initial enable time is longer due to the bandgap settling time and the CPO output capacitor soft-start time. Note 6: 1x mode output impedance is defined as (VIN - VCPO)/IOUT. 2x mode output impedance is defined as (2VIN - VCPO)/IOUT. Note 7: Guaranteed by design.
Typical perForMance characTerisTics
Dropout Time
CPO 1V/DIV 3.6V 1V LED 500mV/DIV 1x MODE DROPOUT DELAY DROPOUT 50s/DIV 0V
3212 G01
2x Mode CPO Ripple
250 2x MODE 5.1V LED DROPOUT VOLTAGE (mV) 200
LED Pin Dropout Voltage vs LED Pin Current
VCPO 20mV/DIV AC COUPLED
150 100
VIN = 3.6V ICPO = 75mA CCPO = 1F
500ns/DIV
3212 G02
50
0
0
5
10 LED CURRENT (mA)
15
20
3212 G03
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LTC3212 Typical perForMance characTerisTics
1x Mode Charge Pump Resistance vs Temperature
6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 -40 VIN = 4.2V VIN = 3V VIN = 3.6V OPEN-LOOP OUTPUT RESISTANCE () ICPO = 50mA 35 33 31 29 27 25 23 21 19 17 C1, C2, C3 = 1F VCPO = 4.8V 15 2.7 3.0 85C CPO VOLTAGE (V) 4.8 3.4V 4.6 3.1V 4.4 4.2 4.0 C1, C2, C3 = 1F 0 10 20 25 30 35 40 45 50 55 60 65 70 CPO CURRENT (mA)
3212 G06
2x Mode CPO Open-Loop Output Resistance
5.2 5.0
2x Mode CPO Voltage vs CPO Current
3.6V
RESISTANCE ()
3.5V 3.3V 3.2V
25C -40C
VIN = 3.0V
-20
40 20 0 TEMPERATURE (C)
60
80
3212 G04
3.3 VIN (V)
3.6
4.0
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Oscillator Frequency vs VIN Voltage
892 890 FREQUENCY (kHz) 888 IVIN (A) 886 884 882 880 2.7 6 5
VIN Shutdown Current vs VIN Voltage
1x Mode No-Load VIN Current vs VIN Voltage
350 340 VIN CURRENT (A) 330 320 310 300 290
4 3 2 1 0
3.1
3.5
3.9 4.3 VIN (V)
4.7
5.1
5.5
2.7
3.1
3.5
3.9 4.3 VIN (V)
4.7
5.1
5.5
2.7
3.1
3.5
3.9 4.3 VIN (V)
4.7
5.1
5.5
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3212 G08
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4.0 3.5 3.0 VIN CURRENT (mA) 2.5 2.0 1.5 1.0 0.5
2x Mode VIN Current vs VIN Voltage
Start-Up and Mode Switch
SOFT-START CPO 1V/DIV 0V LEDEN 2V/DIV 0V VIN = 3.6V 200s/DIV 5V 2x 3.6V MODE DROPOUT 1x DELAY MODE 3.6V
3212 G11
0 2.7
3.1
3.5
3.9 4.3 VIN (V)
4.7
5.1
5.5
3212 G10
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LTC3212 pin FuncTions
CP, CM (Pins 1, 11): Charge Pump Flying Capacitor Pins. A 1F X5R or X7R ceramic capacitor should be connected from CP to CM. CPO (Pin 2): CPO is the output of the charge pump. A 1F X5R or X7R ceramic capacitor is required from CPO to GND. While operating, this pin will supply current to the LEDs and while in shutdown mode this pin will be high impedance. LEDEN (Pin 3): The LEDEN pin is used to program, enable and shut down the part. A 3A internal current source pulls this pin to ground. ISETB, ISETR, ISETG (Pins 4, 5, 6): LED current programming resistor pins. A resistor connected between a pin and GND is used to set the LED current. A resistor from ISETG to GND is required. Resistors on ISETR and ISETB are optional. If ISETR and/or ISETB is not connected to a resistor ISETR's and/or ISETB's respective output(s) will be automatically programmed by the resistor connected to ISETG. If ISETR or ISETB is unused the pin should be connected to VIN. LEDG, LEDR, LEDB (Pins 7, 8, 9): These pins are the LED current output pins. The LEDs are connected from either the charge pump or VIN (anode) to LED (R, G, B) (cathode). GND (Pin 10): This pin should be connected directly to a low impedance ground plane. VIN (Pin 12): Supply voltage for the LTC3212. VIN should be bypassed with a low impedance ceramic capacitor to GND of at least 1F of capacitance. Exposed Pad (Pin 13): GND. The Exposed Pad must be soldered to a low impedance ground plane for optimum performance.
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LTC3212 block DiaGraM
1 CP 900kHz OSCILLATOR 12 VIN CPO 10k 2 11 CM
3
LEDEN 3A
CONTROL LOGIC TSD ENR ENG ENB
4
ISETB
5
ISETR
6
ISETG
OPEN DETECTION/ AUTOSET 10 GND
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operaTion
The LTC3212 uses a switched capacitor charge pump to power three LEDs with a programmable regulated current. The part powers up into 1x mode. In this mode VIN is directly connected to CPO. When powering up into 1x mode, the LTC3212 charges the CPO capacitor to near VIN before directly connecting VIN to CPO. This prevents a large in-rush current. 1x mode provides maximum efficiency and minimum noise. The LTC3212 will remain in this mode until one of the LED current source drivers begins to drop out of regulation. When this drop out occurs the LTC3212 will switch to 2x mode after a soft-start period. The part will return to 1x mode when the part is shut down and reprogrammed. The current delivered through the LED load is controlled by an internal programmable low dropout current source. The current is programmed by resistors connected between the ISET(R,G,B) pins and GND.
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- +
VREF
SHUT DOWN
DROPOUT DETECTION
LEDB ENB LED CURRENT SOURCE
+ - + - + -
9
LEDR ENR LED CURRENT SOURCE
8
LEDG ENG LED CURRENT SOURCE
7
LTC3212 operaTion
An overcurrent shutdown mode on the ISET pins will prevent damage to the part and the LED by shutting down the LED drivers. Choosing an RSET value of 5.9k or greater will ensure that the part stays out of this mode. When in normal operating mode current, regulation is achieved by controlling an active current source. In shutdown mode all internal circuitry is turned off and the LTC3212 draws very little current from the VIN supply. The LTC3212 enters shutdown mode after the LEDEN pin is brought low for 350s. Short-Circuit Protection When LEDEN is brought high, the part will connect VIN to CPO through a weak pull-up until CPO has charged to near VIN. After the LTC3212 detects that the CPO voltage is near the VIN voltage, it then enables 1x mode. If the CPO is shorted or falls below approximately 1V, then the LTC3212 is disabled. After falling below 1V the LTC3212 will use the weak pull-up to charge CPO to near VIN before re-enabling the chip. Soft-Start To prevent excessive inrush during start-up and mode switching, the LTC3212 employs built-in soft-start circuitry. Soft-start is achieved by increasing the current available to the CPO capacitor over a period of approximately 100s. Charge Pump Strength When the LTC3212 operates in 2x mode, the charge pump can be modeled as a Thevenin equivalent circuit to determine the amount of current available from the effective input voltage and the effective open-loop output resistance, ROL.
ROL
ROL is dependent on a number of factors including the oscillator frequency, flying capacitor values and switch resistances. From Figure 1 we can see that the maximum output current in 2x mode is proportional to: 2VIN - CPO ROL LED Current Programming The LTC3212 includes three accurate, programmable current sources that are capable of driving LED currents up to 25mA continuously. The current is programmed using an external resistor for each channel. The equation for each external resistance is: RSETG = RSETB = RSETR = 177.6 ILEDG 177.6 ILEDB 177.6 ILEDR
Alternatively, if either the ISETR or ISETB pins are connected to VIN, the respective LEDR and/or LEDB current will automatically use the RSETG resistor and be set to: ILEDR = ILEDB = 177.6 RSETG 177.6 RSETG
+
CPO
3212 F01
+ -
2VIN
-
Figure 1. CPO Equivalent Open-Loop
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LTC3212 operaTion
White Mode The LTC3212 has a white mode that automatically scales the current in the red, green and blue LEDs to a preset mix when selected. This allows the currents programmed with the external resistors to be set independently of the ratio needed for white light, increasing the flexibility of programming other colors. The intensity of the white is set by the resistor on ISETG. The ratio used for white mode is: ILEDG = 177.6 RSETG clocked by the rising edges of the LEDEN signal. Refer to Figure 2 for timing details. The outputs are programmed using Table 1.
Table 1. LED Programming
PULSES 1 2 3 4 5 6 7+ R 0 0 0 1 1 1 G 0 1 1 0 0 1 White Mode B 1 0 1 0 1 0
159.8 ILEDR = RSETG ILEDB = Enable Each LED driver output may be programmed on or off by pulsing the LEDEN pin while enabling the LTC3212. An internal counter and decoder selects the output configuration from the number of pulses. This counter is
tPWH 80ns
133.2 RSETG
Mode Switching The LTC3212 will automatically switch from 1x to 2x mode whenever it detects a LED driver is entering dropout. The part will wait approximately 140s before switching to 2x mode. This delay will act as filtering to prevent the part from incorrectly switching to 2x mode due to a momentary glitch on the VIN supply. The mode may be reset by entering shutdown mode and reprogramming.
tSD 350s
LEDEN tEN 400s
tPWL 80ns LED CURRENT
PROGRAMMED CURRENT SHUTDOWN
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Figure 2. LED Selection and Shutdown Timing Diagram
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LTC3212 applicaTions inForMaTion
VIN, CPO Capacitor Selection The style and value of the capacitors used with the LTC3212 determine several important parameters such as regulator control loop stability, output ripple, charge pump strength and minimum start-up time. To reduce noise and ripple, it is recommended that low equivalent series resistance (ESR) ceramic capacitors are used for both CVIN and CCPO. Tantalum and aluminum capacitors are not recommended due to high ESR. The value of CCPO directly controls the amount of output ripple for a given load current. Increasing the size of CCPO will reduce output ripple at the expense of longer start-up time. The peak-to-peak output ripple of the 2x mode is approximately given by the expression: VRIPPLEP-P IOUT = 2fOSC * CCPO voltage is applied. Therefore, when comparing different capacitors, it is often more appropriate to compare the amount of achievable capacitance for a given case size rather than comparing the specified capacitance value. For example, over rated voltage and temperature conditions, a 1F, 10V, Y5V ceramic capacitor in a 0603 case may not provide any more capacitance than a 0.22F, 10V, X7R available in the same case. The capacitor manufacturer's data sheet should be consulted to determine what value of capacitor is needed to ensure minimum capacitances at all temperatures and voltages. Table 2 shows a list of ceramic capacitor manufacturers and how to contact them:
Table 2. Recommended Capacitor Vendors
AVX Kemet Murata Taiyo Yuden Vishay www.avxcorp.com www.kemet.com www.murata.com www.t-yuden.com www.vishay.com
where fOSC is the LTC3212 oscillator frequency or typically 900kHz and CCPO is the output storage capacitor. Flying Capacitor Selection Warning: Polarized capacitors such as tantalum or aluminum should never be used for the flying capacitors since their voltage can reverse upon start-up of the LTC3212. Ceramic capacitors should always be used for the flying capacitors. The flying capacitors control the strength of the charge pump. In order to achieve the rated output current it is necessary to have at least 0.6F of capacitance for flying capacitor. Capacitors of different materials lose their capacitance with higher temperature and voltage at different rates. For example, a ceramic capacitor made of X7R material will retain most of its capacitance from -40C to 85C whereas a Z5U or Y5V style capacitor will lose considerable capacitance over that range. Z5U and Y5V capacitors may also have a very poor voltage coefficient causing them to lose 60% or more of their capacitance when the rated
Layout Considerations and Switching Noise The LTC3212 has been designed to minimize EMI. However due to its high switching frequency and the transient currents produced by the LTC3212, careful board layout is necessary. A true ground plane and short connections to all capacitors will improve performance and ensure proper regulation under all conditions. The flying capacitor pins CP and CM will have 5ns to 10ns edge rate waveforms. The large dv/dt on these pins can couple energy capacitively to adjacent PCB runs. Magnetic fields can also be generated if the flying capacitors are not close to the LTC3212 (i.e., the loop area is large). To decouple capacitive energy transfer, a Faraday shield may be used. This is a grounded PCB trace between the sensitive node and the LTC3212 pins. For a high quality AC ground, it should be returned to a solid ground plane that extends all the way to the LTC3212.
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LTC3212 applicaTions inForMaTion
Power Efficiency To calculate the power efficiency () of an LED driver chip, the LED power should be compared to the input power. The difference between these two numbers represents lost power whether it is in the charge pump or the current sources. Stated mathematically, the power efficiency is given by: P = LED PIN The efficiency of the LTC3212 depends upon the mode in which it is operating. Recall that the LTC3212 operates as a pass switch, connecting VIN to CPO, until dropout is detected at an ILED pin. This feature provides the optimum efficiency available for a given input voltage and LED forward voltage. When it is operating as a switch, the efficiency is approximated by: = PLED VLED * ILED VLED = = PIN VBAT * IBAT VBAT Once dropout is detected at any LED pin, the LTC3212 enables the charge pump in 2x mode. In 2x boost mode, the efficiency is similar to that of a linear regulator with an effective input voltage of 2 times the actual input voltage. In an ideal 2x charge pump, the power efficiency would be given by: IDEAL = PLED V *I V = LED LED = LED PIN VBAT * 2 * ILED 2 * VBAT
In some applications it may be possible to increase the efficiency of the LTC3212. If any of the LED's maximum forward voltage is less than the minimum VIN supply voltage minus ILED dropout voltage then the charge pump is not needed to drive that LED. This is often the case with the red LED due to its lower forward voltage. Its anode may be connected directly to VIN, bypassing the charge pump's losses in 2x mode. Thermal Management If the junction temperature increases above approximately 140C the thermal shutdown circuitry will automatically deactivate the output current sources and charge pump. To reduce maximum junction temperature, a good thermal connection to the PC board is recommended. Connecting the Exposed Pad to a ground plane and maintaining a solid ground plane under the device will reduce the thermal resistance of the package and PC board considerably.
since the input current will be very close to the sum of the LED currents. At moderate to high output power, the quiescent current of the LTC3212 is negligible and the expression above is valid.
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0
LTC3212 packaGe DescripTion
(Reference LTC DWG # 05-08-1723 Rev O)
0.64 0.05 (2 SIDES) 0.70 0.05 2.55 0.05 1.15 0.05 PACKAGE OUTLINE 0.25 0.05 2.39 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 3.00 0.10 (2 SIDES) R = 0.05 TYP 2.00 0.10 (2 SIDES) 0.64 0.10 (2 SIDES) 6 0.23 0.05 2.39 0.10 (2 SIDES) BOTTOM VIEW--EXPOSED PAD R = 0.115 TYP 7 0.40 0.10 12 0.45 BSC
DDB Package 12-Lead Plastic DFN (3mm x 2mm)
PIN 1 BAR TOP MARK (SEE NOTE 6) 0.200 REF
1
PIN 1 R = 0.20 OR 0.25 x 45 CHAMFER
(DDB12) DFN 0106 REV O
0.75 0.05
0.45 BSC
0 - 0.05
NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE
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Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
LTC3212 Typical applicaTion
Three Independent Programming Resistors (10mA, 15mA, 20mA)
1F
VIN 2.7V TO 5.5V
CM VIN 1F LEDEN ISETB ISETR ISETG
CP CPO
CPO 1F
LTC3212 LEDB LEDR LEDG LEDR = 10mA LEDB = 15mA LEDG = 20mA
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11.8k
17.8k
8.87k
relaTeD parTs
PART NUMBER LTC3200-5 LTC3201 LTC3202 LTC3205 LTC3206 LTC3208 LTC3209 LTC3210/ LTC3210-1 LTC3210-2 LTC3210-3 LTC3214 LTC3215 LTC3216 LTC3217 LT3465/ LT3465A DESCRIPTION Low Noise, 2MHz Regulated Charge Pump White LED Driver Low Noise, 1.7MHz Regulated Charge Pump White LED Driver Low Noise, 1.5MHz Regulated Charge Pump White LED Driver Multidisplay LED Controller I2C Multidisplay LED Controller High Current Software Configurable Multidisplay LED Controller 600mA MAIN/Camera LED Controller 500mA MAIN/Camera LED Controller COMMENTS Up to 6 White LEDs, VIN: 2.7V to 4.5V, VOUT(MAX) = 5V, IQ = 8mA, ISD 1A, ThinSOT Package Up to 6 White LEDs, VIN: 2.7V to 4.5V, VOUT(MAX) = 5V, IQ = 6.5mA, ISD 1A, 10-Lead MS Package Up to 8 White LEDs, VIN: 2.7V to 4.5V, VOUT(MAX) = 5V, IQ = 5mA, ISD 1A, 10-Lead MS Package 92% Efficiency, VIN: 2.8V to 4.5V, IQ = 50A, ISD 1A, 4mm x 4mm QFN Package 92% Efficiency, 400mA Continuous Output Current; Up to 11 White LEDs in 4mm x 4mm QFN Package 95% Efficiency, VIN: 2.9V to 4.5V, 1A Output Current; Up to 17 LEDs for 5 Displays, 5mm x 5mm QFN Package Up to 8 LEDs, 94% Efficiency, VIN: 2.9V to 4.5V, 1x/1.5x/2x Boost Modes, 4mm x 4mm QFN Package Up to 5 LEDs, 95% Efficiency, VIN: 2.9V to 4.5V, 1x/1.5x/2x Boost Modes, Exponential Brightness Control, "-1" Version Has 64-Step Linear Brightness Control, 3mm x 3mm QFN Package Drives 4 MAIN LEDs, 3mm x 3mm QFN Package Drives 3 MAIN LEDs, 3mm x 3mm QFN Package 93% Efficiency, VIN: 2.9V to 4.4V, 1x/1.5x/2x Boost Modes, 3mm x 3mm DFN Package 93% Efficiency, VIN: 2.9V to 4.4V, 1x/1.5x/2x Boost Modes, 3mm x 3mm DFN Package 93% Efficiency, VIN: 2.9V to 4.4V, 1x/1.5x/2x Boost Modes, Independent Low/High Current Programming Up to 4 LEDs, 92% Efficiency, VIN: 2.9V to 4.5V, 1x/1.5x/2x Boost Modes, Independent Torch and Flash ISET and Enable Pins, 3mm x 3mm QFN Package
MAIN/CAM LED Controller with 32-Step Brightness Control MAIN/CAM LED Controller with 32-Step Brightness Control 500mA Camera LED Charge Pump 700mA High Current, Low Noise, White LED Driver 1A High Current, Low Noise, White LED Driver 600mA Low Noise Multi-LED Camera Light Charge Pump
1.2MHz/2.4MHz White LED Boost Converters with Up to 6 White LEDs, VIN: 12.7V to 16V, VOUT(MAX) = 34V, IQ = 1.9mA, ISD <1A, Internal Schottky ThinSOT Package
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ThinSOT is a trademark of Linear Technology Corporation.
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 FAX: (408) 434-0507
LT 0707 REV B * PRINTED IN USA
www.linear.com
LINEAR TECHNOLOGY CORPORATION 2007

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