# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

MAXIM INTEGRATED PRODUCTS MAX8645X MAX8645Y Data Sheet

Summary

This advanced charge pump is designed to power sophisticated white LED backlights and flash units in portable electronics like smartphones and digital cameras. It features high efficiency, dual low-noise LDOs, and adaptive charging modes for flexible brightness control. The manual provides detailed technical specifications, wiring diagrams, component requirements, and operating parameters necessary for system engineers developing reliable, energy-efficient illumination solutions.

📄 Preview PAGE OF 15

Page 1 Text Content

19-3978; Rev 3; 12/06

EVALUATION KIT AVAILABLE

1x/1.5x/2x White LED Charge Pumps with

Two LDOs in 4mm x 4mm TQFN General Description Features

The MAX8645X/MAX8645Y charge pumps drive up to

Power Up to Eight LEDs

eight white LEDs with regulated constant current for uni-

Up to 30m A/LED Drive for Backlight

form intensity. The main group of LEDs (M1–M6) can be driven up to 30m A per LED for backlighting. The flash Up to 400m A Total Drive for Flash group of LEDs (F1 and F2) is independently controlled

Two Internal Low-Noise 200m A LDOs

and can be driven up to 200m A per LED (or 400m A total). Two 200m A LDOs are on-board to provide power for

94% Max/85% Avg Efficiency (PLED/PBATT) over Li+

camera functions. The LDOs’ output voltages are pin pro-

Battery Discharge

grammable to meet different camera-module require- ments. The MAX8645X and MAX8645Y differ only in LDO

0.2% Typical LED Current Matching

output voltages. By utilizing adaptive 1x/1.5x/2x charge- pump modes and very-low-dropout current regulators, Adaptive 1x/1.5x/2x Mode Switchover the MAX8645X/MAX8645Y achieve high efficiency over

Flexible Brightness Control

the full 1-cell lithium-battery voltage range. The 1MHz fixed-frequency switching allows for tiny external compo- Single-Wire, Serial-Pulse Interface (32 Steps) nents, and the regulation scheme is optimized to ensure

2-Bit Logic (Three Levels)

low EMI and low input ripple.

Thermal TA Derating Function

The MAX8645X/MAX8645Y are available in a 28-pin TQFN, 4mm x 4mm (0.8mm max height) lead-free package.

Low Input Ripple and EMI

2.7V to 5.5V Supply Voltage Range

Applications

Soft-Start, Overvoltage, and Thermal-Shutdown

Camera Phones and Smartphones

Protection

Backlighting and Flash

28-Pin TQFN, 4mm x 4mm Package

PDAs, Digital Cameras, and Camcorders

Typical Operating Circuit Ordering Information

PIN- PKG

PART TEMP RANGE

PACKAGE CODE

INPUT OUTPUT

2.7V TO 5.5V UP TO 580m A

PIN OUT 28 TQFN-EP

MAX8645XETI+ -40°C to +85°C T2844-1

10μF MAIN FLASH

IN 4mm x 4mm

MAX8645X 28 TQFN-EP GND MAX8645Y M1 MAX8645YETI+ -40°C to +85°C T2844-1

PGND 4mm x 4mm

M3 EP = Exposed paddle.

M4 +Denotes a lead-free package.

MAIN ON/OFF M5 AND DIMMING

ENM2 M6 F1

F2FLASH ON/OFF DUAL-LDO ON/OFF ENLDO LDO1 CAMERA

LDO2 MODULEDUAL-LDO

VOLTAGE 1μF1μF

SELECTION P2

SETF REFSETM Pin Configuration appears at end of data sheet.

Maxim Integrated Products

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Page Summary Contents For MAXIM INTEGRATED PRODUCTS MAX8645X MAX8645Y Data Sheet

Page 1 19-3978; Rev 3; 12/06 EVALUATION KIT AVAILABLE 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN General Description Features The MAX8645X/MAX8645Y charge pumps drive up to Power Up to...
Page 2 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN ABSOLUTE MAXIMUM RATINGS PIN, IN, OUT, REFBP to GND................................-0.3V to +6.0V OUT, LDO1, LDO2 Short Circuit to GND...
Page 3 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN ELECTRICAL CHARACTERISTICS (continued) (VIN = 3.6V, VGND = VPGND = 0V, ENM1 = ENM2 = ENF = IN, RSETM = RSETF = 6.8kΩ, P1 = P2 = unconn...
Page 4 EF FI CI EN CY LE D/ AT T ( 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN ELECTRICAL CHARACTERISTICS (continued) (VIN = 3.6V, VGND = VPGND = 0V, ENM1 = ENM2 = ENF = IN, RSETM = RSE...
Page 5 TO TA LE CU RR EN (m A) IN PU RI PP LE (m BA TT ER CU RR EN (m A) 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN Typical Operating Characteristics (continued) (VIN = VEN_ = 3.6V, ci...
Page 6 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN FL AS LE CU RR EN (m A) Typical Operating Characteristics (continued) (VIN = VEN_ = 3.6V, circuit of Figure 2, TA = +25°C, unless othe...
Page 7 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN OU TP UT OL TA GE CC UR AC Typical Operating Characteristics (continued) (VIN = VEN_ = 3.6V, circuit of Figure 2, TA = +25°C, unless o...
Page 8 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN Pin Description PIN NAME FUNCTION Supply Voltage Input. Bypass to PGND with a 10µF ceramic capacitor. The input voltage range is 2.7V ...
Page 9 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN Pin Description (continued) PIN NAME FUNCTION Transfer Capacitor 1 Positive Connection. Connect a 1µF ceramic capacitor between C1P an...
Page 10 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN INITIAL t HI ≥ 200μs ENM1 AND ENM2 OR t SOFT-START ENF t SHDN t LO t HI 2ms (typ) ≥ 500ns500ns TO 250μs IM_ OR IF_ SHUTDOWN SHUTDOWN F...
Page 11 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN C3 C4 1μF 1μF INPUT 2.7V TO 5.5V PIN LDO1 IN LDO2 GND 1μF OUTPUT UP TO 480m A ON MAX8645X C5 MAIN FLASH ENM2 MAX8645Y 10μF PWM INPUT E...
Page 12 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN INPUT 2.7V TO 5.5V PIN LDO1 10μF IN LDO2 OUTPUT UP TO 240m A MAX8645X MAIN FLASH ENM2 MAX8645Y ON/OFF AND ENF VOLTAGE ENLDO M3 SELECTI...
Page 13 1x/1.5x/2x White LED Charge Pump with Two LDOs in 4mm x 4mm TQFN Table 3. Recommended Components for Figure 2 DESIGNATION VALUE MANUFACTURER PART DESCRIPTION C1, C5 10µF TDK C2012X5R0J106M 10µF ±20%, ...
Page 14 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm Thin QFN Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest pac...
Page 15 1x/1.5x/2x White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the la...

Manual Details

Brand Maxim Integrated
Pages 15
File Size 310.70 KB
Published May 26, 2026
77 views

Enter the captcha to get the download link:

captcha

Frequently Asked Questions

What are the maximum current limits for the LED groups?

The main group (M1–M6) handles up to 30mA/LED (totaling 150mA), while the flash group (F1 and F2) can be driven up to 400mA total.

Does this chip support different voltage requirements?

Yes, it includes two internal low-noise LDOs providing power for battery discharge, with output voltages configurable to meet various camera module needs.

What is the operational temperature range?

The typical operating temperature range is from -40°C to +85°C. The absolute maximum junction temperature is +150°C.

How does the chip ensure high efficiency across different battery levels?

It uses adaptive 1x/1.5x/2x charge-pump mode switchover and low-dropout current regulators, optimizing performance over the full 1-cell lithium-battery voltage range.