LT1932ES6

LT1932 LINER | Alldatasheet

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Technical content

1932 is a fixed frequency step-up DC/DC converter designed to operate as a constant-current source. Be- cause it directly regulates output current, the LT1932 is ideal for driving light emitting diodes (LEDs) whose light intensity is proportional to the current passing through them, not the voltage across their terminals. With an input voltage range of 1V to 10V, the device works from a variety of input sources. The LT1932 accurately regulates LED current even when the input voltage is higher than the LED voltage, greatly simplifying battery- powered designs. A single external resistor sets LED current between 5mA and 40mA, which can then be easily adjusted using either a DC voltage or a pulse width modulated (PWM) signal. When the LT1932 is placed in shutdown, the LEDs are disconnected from the output, ensuring a quiescent current of under 1 mA for the entire circuit. The device’s 1.2MHz switching frequency permits the use of tiny, low profile chip inductors and capacitors to minimize footprint and cost in space-conscious portable applications. n Up to 80% Efficiency n Inherently Matched LED Current n Drives Five White LEDs from 2V n Drives Six White LEDs from 2.7V n Drives Eight White LEDs from 3V n Precise, Adjustable Control of LED Current n Disconnects LEDs In Shutdown n 1.2MHz Fixed Frequency Switching n Uses Tiny Ceramic Capacitors n Uses Tiny 1mm-Tall Inductors n Regulates Current Even When VIN > VOUT n Operates with VIN as Low as 1V n Low Profile (1mm) ThinSOT TM Package n Cellular Telephones n Handheld Computers n Digital Cameras n Portable MP3 Players n Pagers 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. FEATURES DESCRIPTIO U APPLICATIO SU TYPICAL APPLICATIO U Li-Ion Driver for Four White LEDs Efficiency Final Electrical Specifications , LTC and LT are registered trademarks of Linear Technology Corporation. VIN SW 15mA

1932 TA01

6.8µHVIN 2.7V TO 4.2V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 C2: TAIYO YUDEN EMK212BJ105 D1:ZETEX ZHCS400 L1: SUMIDA CLQ4D106R8 OR PANASONIC ELJEA6R8 R SET 1.50k PWM DIMMING CONTROL 4.7µF 1µF

35 LED

LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA02

VIN = 4.2V VIN = 2.7V ThinSOT is a trademark of Linear Technology Corporation.

PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Input Voltage 1V Quiescent Current V RSET = 0.2V 1.2 1.6 mA VSHDN = 0V 0.1 1.0 mA RSET Pin Voltage R SET = 1.50k 100 mV LED Pin Voltage R SET = 1.50k, VIN < VOUT (Figure 1) 120 180 mV LED Pin Current R SET = 562W , VIN = 1.5V 34 38 42 mA RSET = 750W , VIN = 1.2V 26 30 34 mA RSET = 1.50k, VIN = 1.2V 12.5 15 17.5 mA RSET = 4.53k, VIN = 1.2V 5 mA LED Pin Current Temperature Coefficient I LED = 15mA –0.02 mA/ °C Switching Frequency V IN = 1V 0.8 1.2 1.6 MHz Maximum Switch Duty Cycle l 90 95 % Switch Current Limit 400 550 780 mA Switch VCESAT ISW = 300mA 150 200 mV SHDN Pin Current V SHDN = 0V 0 0.1 mA VSHDN = 2V 15 30 mA Start-Up Threshold (SHDN Pin) 0.85 V Shutdown Threshold (SHDN Pin) 0.25 V Switch Leakage Current Switch Off, V SW = 5V 0.01 5 mA (Note 1) R Operating Temperature Range (Note 2) .. – 40°C to 85°C ORDER PART NUMBER LT1932ES6 TJMAX = 125°C, qJA = 250°C/ W The l denotes specifications that apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 1.2V, VSHDN = 1.2V, unless otherwise noted. ABSOLUTE AXI U RATI GSW WW U PACKAGE/ORDER I FOR ATIOUU W

ELECTRICAL CHARACTERISTICS

6 VIN

5 SHDN

4 RSET

Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LT1932E is guaranteed to meet specifications from 0°C to 70°C. Specifications over the – 40 °C to 85 °C operating temperature range are assured by design, characterization and correlation with statistical process controls. Consult LTC Marketing for parts specified with wider operating temperature ranges.

TYPICAL PERFOR A CE CHARACTERISTICS UW Switch Saturation Voltage (VCESAT) SWITCH CURRENT (mA) SWITCH SATURATION VOLTAGE (mV) 150 200 250 300 500

1932 G01

TJ = 125°C TJ = –50°C TJ = 25°C TEMPERATURE (°C) –50 400 500 700 25 75

1932 G02

–25 0 50 100 125 100 600PEAK CURRENT (mA) VIN = 1.2V VIN = 10V TEMPERATURE (°C) –50 SWITCHING FREQUENCY (MHz) 0.2 0.6 0.8 1.0 2.0 1.4 0 50 75

1932 G03

0.4 1.6 1.8 1.2 –25 25 100 125 VIN = 1.2V VIN = 10V Switch Current Limit Switching Frequency LED Pin Voltage LED Current LED CURRENT (mA) LED PIN VOLTAGE (mV) 150 200 250 15 25

1932 G04

TJ = 125°C TJ = 25°C TJ = –50°C TEMPERATURE (°C) –5 0 LED CURRENT (mA)

1932 G05

–2 5 0 5 0 75 100 125 RSET = 750Ω RSET = 562Ω RSET = 1.50k RSET = 4.53k Quiescent Current SHDN Pin Current LED Current INPUT VOLTAGE (V) LED CURRENT (mA)

1932 G06

RSET = 750Ω RSET = 562Ω RSET = 1.50k RSET = 4.53k TEMPERATURE (°C) –5 0 QUIESCENT CURRENT (mA) 1.75

1932 G07

1.00 0.50 –2 5 0 5 0 0.25 2.00 1.50 1.25 0.75 75 100 125 VIN = 1.2V VIN = 10V SHDN PIN VOLTAGE (V) SHDN PIN CURRENT

1932 G08

TJ = 125°C TJ = 25°C TJ = –50°C Switching Waveforms VSW 10V/DIV IL1 200mA/DIV VOUT 20mV/DIV AC COUPLED ILED 10mA/DIV VIN = 3V 0.5 ms/DIV 1093 G09

4 WHITE LEDs

ILED = 15mA CIRCUIT ON FIRST PAGE OF THIS DATA SHEET

5 SHDNC1 C2

1932 F01

Figure 1. LT1932 Block Diagram control scheme to regulate the output current, I LED. power switch Q1 and LED switch Q2. nected to this pin to minimize EMI. programs the LED current (that flows into the LED pin). This pin is also used to provide LED dimming. 0.85V to turn on the LT1932; tie below 0.25V to turn it off. capacitor to ground as close to the device as possible.

in Table 1. Many different sizes and shapes are available. a good choice for most LT1932 designs. Table 1. Recommended Inductors efficiency by up to 12% over the smaller, thinner ones. Keep this in mind when choosing an inductor. higher peak currents in the switch, inductor and diode. Figure 2. Efficiency for Several Different Inductor Types Figure 3. Efficiency for Several Different Inductor Values

1932 F02

1932 F03

having strict height requirements. Table 2. Recommended Ceramic Capacitor Manufacturers diode has a voltage rating greater than the output voltage. or 0.5A diode will be sufficient for most designs. Table 3. Recommended Schottky Diodes values, use the following equation to choose RSET. Table 4. RSET Resistor Values

1932 F04

Figure 4. LED Driver with Open-Circuit Protection LT1932, reducing the total quiescent current to zero. Figure 5. PWM Dimming Using the SHDN Pin

Figure 6. R Figure 6. Five Methods of LED Dimming the DC control voltage is at VMAX). saturation to keep the LED current in regulation.

1932 F06

4 RPWM

4 RINCR

Burst Mode is a trademark of Linear Technology Corporation.

Figure 7. Recommended Component Placement

1932 F07

paid to the PCB board layout and component placement. nent placement is shown in Figure 7.

1932 TA14a

5 LED

1932 TA14b

1932 TA03a

4.7µHVIN 1V TO 1.5V LT1932 SHDN C1, C2: TAIYO YUDEN JMK212BJ475 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 R SET 1.50k 2.5V PWM DIMMING CONTROL 4.7µF 4.7µF 24.9k 2 Single Cell Driver for One White LED VIN SW 15mA

1932 TA04a

4.7µHVIN 1V TO 1.5V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN LMK212BJ225 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 R SET 1.50k 2.5V PWM DIMMING CONTROL 4.7µF 2.2µF 24.9k 2 Single Cell Driver for Two White LEDs Efficiency Efficiency LED CURRENT (mA) EFFICIENCY (%) 51 01 52.5 7.5 12.5

1932 TA03b

VIN = 1.5V VIN = 1.1V LED CURRENT (mA) EFFICIENCY (%)60 51 01 52.5 7.5 12.5

1932 TA04b

VIN = 1.5V VIN = 1.1V TYPICAL APPLICATIO SU

1932 TA06a

4.7µHVIN 1.8V TO 3V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN EMK316BJ225 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 R SET 1.50k 2.5V DC DIMMING CONTROL 4.7µF 2.2µF 60.4k 2 2-Cell Driver for Three White LEDs Efficiency LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA06b

VIN = 3V VIN = 1.8V 2-Cell Driver for Two White LEDs VIN SW 15mA

1932 TA15a

4.7µHVIN 1.8V TO 3V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN LMK212BJ225 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 R SET 1.50k 2.5V DC DIMMING CONTROL 4.7µF 2.2µF 60.4k 2 LED CURRENT (mA) EFFICIENCY (%) 10 2051 5

1932 TA15b

VIN = 3V VIN = 1.8V Efficiency

2-Cell Driver for Five White LEDs VIN SW 15mA

1932 TA05a

4.7µHVIN 2V TO 3V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN TMK316BJ105 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 R SET 1.50k PWM DIMMING CONTROL 4.7µF 1µF

1932 TA07a

4.7µHVIN 1.8V TO 3V LT1932 SHDN RSET 1.50k PWM DIMMING CONTROL 4.7µF 1µF C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN EMK212BJ105 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 2-Cell Driver for Four White LEDs Efficiency LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA05b

VIN = 3V VIN = 2V LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA07b

VIN = 3V VIN = 1.8V TYPICAL APPLICATIO SU

Li-Ion Driver for Two White LEDs Efficiency Li-Ion Driver for Three White LEDs Efficiency VIN SW 15mA

1932 TA08a

6.8µHVIN 2.7V TO 4.2V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN LMK212BJ225 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: PANASONIC ELJEA6R8 (714) 373-7334 R SET 1.50k 3.3V PWM DIMMING CONTROL 4.7µF 2.2µF 31.6k 2

1932 TA09a

6.8µHVIN 2.7V TO 4.2V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN EMK316BJ225 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: PANASONIC ELJEA6R8 (714) 373-7334 R SET 1.50k 3.3V PWM DIMMING CONTROL 4.7µF 2.2µF 31.6k 2 LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA08b

VIN = 4.2V VIN = 2.7V LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA09b

VIN = 4.2V VIN = 2.7V

Li-Ion Driver for Four White LEDs Efficiency VIN SW 15mA

1932 TA10a

6.8µHVIN 2.7V TO 4.2V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN EMK212BJ105 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: PANASONIC ELJEA6R8 (714) 373-7334 R SET 1.50k PWM DIMMING CONTROL 4.7µF 1µF LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA10b

VIN = 4.2V VIN = 2.7V Li-Ion Driver for Five White LEDs Efficiency VIN SW 15mA

1932 TA11a

4.7µHVIN 2.7V TO 4.2V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN TMK316BJ105 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 R SET 1.50k PWM DIMMING CONTROL 4.7µF 1µF LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA11b

VIN = 4.2V VIN = 2.7V

Li-Ion Driver for Eight White LEDs Efficiency VIN SW

1932 TA13a

4.7µHVIN 3V TO 4.2V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN GMK316BJ105 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 R SET 1.50k 3.3V DC DIMMING CONTROL 4.7µF 1µF 80.6k 2 LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA13b

VIN = 4.2V VIN = 3V UPACKAGE DESCRIPTIO 6-Lead Plastic SOT-23 (LTC DWG # 05-08-1634) (LTC DWG # 05-08-1636) L DATUM ‘A’ .09 – .20 (.004 – .008) (NOTE 2) S6 SOT-23 0401 A A2 1.90 (.074) REF .20 (.008) 1.50 – 1.75 (.059 – .069) (NOTE 3) 2.60 – 3.00 (.102 – .118) .25 – .50 (.010 – .020) (6PLCS, NOTE 2) 2.80 – 3.10 (.110 – .118) (NOTE 3) .95 (.037) REF PIN ONE ID MILLIMETERS (INCHES) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS 2. DIMENSIONS ARE IN 3. DRAWING NOT TO SCALE 4. DIMENSIONS ARE INCLUSIVE OF PLATING 5. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 6. MOLD FLASH SHALL NOT EXCEED .254mm 7. PACKAGE EIAJ REFERENCE IS: SC-74A (EIAJ) FOR ORIGINAL JEDEL MO-193 FOR THIN .90 – 1.45 (.035 – .057) .00 – 0.15 (.00 – .006) .90 – 1.30 (.035 – .051) .35 – .55 (.014 – .021)

1.00 MAX

(.039 MAX)A L .01 – .10 (.0004 – .004) .80 – .90 (.031 – .035) .30 – .50 REF (.012 – .019 REF) SOT-23 (Original) SOT-23 (ThinSOT)

ª LINEAR TECHNOLOGY CORPORATION 2001 1932i LT/TP 0701 1.5K • PRINTED IN USA Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 l FAX: (408) 434-0507 l www.linear.com RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1615 Micropower DC/DC Converter in 5-Lead ThinSOT 20V at 12mA from 2.5V Input, ThinSOT Package LT1617 Micropower Inverting DC/DC Converter in 5-Lead ThinSOT –15V at 12mA from 2.5V Input, ThinSOT Package LT1618 Constant-Current/Constant-Voltage DC/DC Converter Drives 20 White LEDs from Li-Ion, MS10 Package LTC1682 Doubler Charge Pump with Low Noise Linear Regulator 3.3V and 5V Outputs with 60 mVRMS Noise, Up to 80mA Output LT1930 1.4MHz Switching Regulator in 5-Lead ThinSOT 5V at 480mA from 3.3V Input, ThinSOT Package LT1931 Inverting 1.2MHz Switching Regulator in 5-Lead ThinSOT –5V at 350mA from 5V Input, ThinSOT Package LTC3200 Low Noise Regulated Charge Pump 5V Output with Up to 100mA Output UTYPICAL APPLICATIO Li-Ion Driver for Ten White LEDs Efficiency VIN SW 30mA

1932 TA16a

10µHVIN 2.7V TO 4.2V LT1932 SHDN C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN TMK325BJ475 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C100M24 (814) 237-1431 R SET 750Ω 4.7µF 4.7µF 100Ω 100Ω TOTAL LED CURRENT (mA) EFFICIENCY (%) 10 20 3051 52 5

1932 TA16b

VIN = 4.2V VIN = 2.7V EfficiencyLi-Ion Driver for Six White LEDs VIN SW 15mA

1932 TA12a

4.7µHVIN 2.7V TO 4.2V LT1932 SHDN RSET 1.50k 3.3V DC DIMMING CONTROL 4.7µF 1µF 80.6k 2 C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN TMK316BJ105 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C4R7M24 (814) 237-1431 LED CURRENT (mA) EFFICIENCY (%) 51 01 5 2 0

1932 TA12b

VIN = 4.2V VIN = 2.7V