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Catalyst Semiconductor CAT3643 3-Channel Ultra High Efficiency Quad-Mode LED Driver Handbook

Summary

Experience superior power management with this high-efficiency, 3-Channel LED driver. The Quad-Mode fractional charge pump utilizes groundbreaking EZDim™ technology to optimize energy use while precisely powering up to three LEDs across various input voltages. Ideal for electronics manufacturers designing low-power handheld devices, cellular phones, and display backlights. This technical guide provides comprehensive details on operating characteristics, ultra-low noise performance, robust protection features, and seamless system integration for optimal LED illumination performance.

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CAT3643

3-Channel Ultra High Efficiency Quad-Mode™ LED Driver

FEATURES DESCRIPTION High efficiency 1.33x charge pump The CAT3643 is a high efficiency Quad-Mode TM fractional charge pump that can drive up to three

Quad-mode charge pump: 1x, 1.33x, 1.5x, 2x

LEDs programmable by a one wire digital interface.

Drives up to 3 LEDs at 32m A each

The inclusion of a 1.33x fractional charge pump mode 1-wire EZDim™ LED current programming increases device efficiency by up to 10% over traditional 1.5x charge pumps with no added external

Power efficiency up to 92%

capacitors.

Low noise input ripple in all modes

“Zero” current shutdown mode Low noise input ripple is achieved by operating at a constant switching frequency which allows the use of

Soft start and current limiting

small external ceramic capacitors. The multi-fractional

Short circuit protection

charge pump supports a wide range of input voltages Thermal shutdown protection from 2.4V to 5.5V.

Tiny 12-pad XQFN, 12-pad TDFN and 16-pad

The EN/DIM logic input functions as a chip enable and

TQFN packages

a digital dimming interface for current setting of all LEDs. Six different current ratios are available via the

APPLICATION

interface.

LCD Display Backlight

The device is available in the tiny 12-pad XQFN 2.5 x

Cellular Phones

2.5mm with max height of 0.4mm or in 16-pad TQFN

Digital Still Cameras

or 12-pad TDFN 3mm x 3mm package with a max Handheld Devices height of 0.8mm.

ORDERING INFORMATION Catalyst Semiconductor’s Quad-Mode TM 1.33x charge pump switching architecture is patented.

Part Number Package Marking CAT3643HV2-T2 TDFN-12 3 x 3(1) HABF CAT3643HV2-GT2 TDFN-12 3 x 3(2) HABG CAT3643HV3-T2 TQFN-16 3 x 3(1) JAAE

TYPICAL APPLICATION CIRCUIT

CAT3643HV3-GT2 TQFN-16 3 x 3(2) JAAF

CAT3643HL1-T2 XQFN-12 2.5 x 2.5(1) LB Notes:

(1) Matte-Tin Plated Finish (Ro HS-compliant) VOUT

VIN VOUT

(2) Ni Pd Au Plated Finish (Ro HS-compliant) 2.4V CIN COUT to

(3) Quantity per reel is 2000 1µF

5.5V CAT3643 1µF

1-Wire

EZDim TM EN/DIM LED1

For Ordering Information details, see page 16. Programming

4.02kΩ GND

© Catalyst Semiconductor, Inc. 1 Doc. No. MD-5022 Rev. E Characteristics subject to change without notice

Page Summary Contents For Catalyst Semiconductor CAT3643 3-Channel Ultra High Efficiency Quad-Mode LED Driver Handbook

Page 1 CAT3643 3-Channel Ultra High Efficiency Quad-Mode™ LED Driver FEATURES DESCRIPTION High efficiency 1.33x charge pump The CAT3643 is a high efficiency Quad-Mode TM fractional charge pump that can drive...
Page 2 CAT3643 PIN CONFIGURATION TDFN 12-Pad 3 x 3mm (Top View) TQFN 16-Pad 3 x 3mm (Top View) LED1 GND LED2 C2- 11LED2 C2+ VIN LED3 C2+ LED3 C2- RSET C1- NC C1- 8EN/DIM C1+ VO RSET C1+ VOUT VIN LED EN /D IM...
Page 3 CAT3643 ABSOLUTE MAXIMUM RATINGS Parameter Rating Unit VIN, LEDx, C1±, C2±, EN/DIM, RSET voltage 6 V VOUT voltage 7 V Storage Temperature Range -65 to +160 °C Junction Temperature Range -40 to +150 °C...
Page 4 CAT3643 RECOMMENDED EN/DIM TIMING For 2.4V ≤ VIN ≤ 5.5V, over full ambient temperature range -40ºC to +85ºC. Symbol Name Conditions Min Typ Max Units TSETUP EN/DIM setup from shutdown 10 μs TLO EN/DIM...
Page 5 CAT3643 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6V, IOUT = 60m A (3 LEDs at 20m A), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified. LE IA TI ] . IE [m FF IC IE ] 1x Efficiency ...
Page 6 CAT3643 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6V, IOUT = 60m A (3 LEDs at 20m A), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified. IT IN [M z] Switching Frequency vs. Temperat...
Page 7 CAT3643 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6V, IOUT = 60m A (3 LEDs at 20m A), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified. Power Up Delay (1x Mode) Power Down Delay (1...
Page 8 CAT3643 TYPICAL PERFORMANCE CHARACTERISTICS TP LT [V VIN = 3.6V, IOUT = 60m A (3 LEDs at 20m A), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified. Foldback Current Limit LED Current ...
Page 9 CAT3643 PIN DESCRIPTION Name Function LED1 LED1 cathode terminal. LED2 LED2 cathode terminal. LED3 LED3 cathode terminal. RSET Connect resistor RSET to set the LED current. EN/DIM Device enable (activ...
Page 10 CAT3643 BLOCK DIAGRAM 1x mode (LDO) VOUT 1.33x, 1.5x, 2x Charge Pump Mode Control 1, 1.3MHz EN/DIM Oscillator Serial Reference Interface Voltage LED3 Current LED Channel Registers Setting DAC Current ...
Page 11 CAT3643 LED Current Selection At power-up, the initial LED current is set to full scale levels by pulsing the input signal, as shown on Figure 3. (100% brightness) by the external resistor RSET as On ...
Page 12 CAT3643 Unused LED Channels External Components For applications not requiring all the channels, it is The driver requires four external 1μF ceramic capaci– recommended the unused LED pins be tied dir...
Page 13 CAT3643 PACKAGE OUTLINE DRAWING TDFN 12-Pad 3 x 3mm (HS2, HV2) (1)(2) PIN#1 ID PIN#1 INDEX AREA A1 TOP VIEW SIDE VIEW BOTTOM VIEW SYMBOL MIN NOM MAX FRONT VIEW 0.45 BSC For current Tape and Reel infor...
Page 14 CAT3643 TQFN 16-Pad 3 x 3mm (HS3, HV3) (1)(2) PIN#1 ID PIN#1 INDEX AREA A1 SIDE VIEWTOP VIEW BOTTOM VIEW SYMBOL MIN NOM MAX 0.18 0.23 0.30 FRONT VIEW 2.90 3.00 3.10 0.50 BSC For current Tape and Reel ...
Page 15 CAT3643 XQFN 12-Pad 2.5 x 2.5mm with 0.4mm max height (HL1) (1)(2) Pin 1 Dot By marking PIN #1 INDICATOR R 0.100 TOP VIEW BOTTOM VIEW SYMBOL MIN NOM MAX AA1A2 SIDE VIEW 0.50 BSC DETAIL A For current T...
Page 16 CAT3643 EXAMPLE OF ORDERING INFORMATION(1) Prefix Device # Suffix CAT 3643 HV3 -G T2 Product Number Lead Finish Blank: Matte-Tin G: Ni Pd Au Optional Package Company ID HV2: TDFN Tape & Reel HV3: ...
Page 17 REVISION HISTORY Date Rev. Reason 01/29/2007 A Initial Release 03/06/2007 B Electrical Operating Characteristics – Add the pull-down resistor value 100kΩ Block Diagram – Add a 100kΩ pull-down resistor...

Manual Details

Brand QUAD
Pages 17
File Size 339.22 KB
Published May 27, 2026
72 views

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Frequently Asked Questions

What are the different operational modes of the CAT3643 driver?

It supports Quad-Mode operation, allowing for four distinct output levels: 1x, 1.33x, 1.5x, and 2x.

What protective features does the device include?

It incorporates short circuit protection and thermal shutdown protection to ensure safe operation.

In what physical packages is the CAT3643 offered?

The chip is available in three package formats: XQFN-12, TDFN-12, or TQFN-16.

How is LED dimming programmed using this module?

Dimming is controlled by a 1-wire digital interface connected to the EN/DIM pin for precise current setting of all LEDs.