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General Description

The MAX8630W/MAX8630X charge pumps drive up to 5

white LEDs with regulated constant current up to 125mA

total. By utilizing adaptive 1x/1.5x charge-pump modes

and very low-dropout current regulators, they achieve

high efficiency over the full 1-cell Li+ battery input volt-

age range. The 1MHz fixed-frequency switching allows

for tiny external components, and the regulation scheme

is optimized to ensure low EMI and low input ripple. An

integrated derating function protects the LEDs from

overheating during high ambient temperatures.

The MAX8630W/MAX8630X are factory trimmed for full-

scale LED current options of 15mA, 18mA, 20mA, and

25mA. The MAX8630X uses two enable inputs (ENM for

3 main LEDs and ENS for 2 sub LEDs) for simple on/off

control and single-wire, serial-pulse dimming in 32 linear

steps. The MAX8630W uses a single direct PWM input

(PWM) to control all 5 LEDs with DC current proportional

to the PWM duty cycle. If both ENM and ENS (or PWM)

are kept low for more than 4ms, the MAX8630_ enters

shutdown. The MAX8630W/MAX8630X are available in a

14-pin, 3mm x 3mm TDFN package (0.8mm max height).

Applications

Display Backlight (Up to 5 LEDs)

Main (3 LEDs) + Sub (2 LEDs) Displays

Cell Phones and Smartphones

PDAs, Digital Cameras, and Camcorders

Features

♦ 93% Max/85% Avg. Efficiency (P

LED

BATT

) Over

Li+ Battery Discharge

♦ 1% LED Current Accuracy

♦ 125mA Total Drive Capability

♦ Adaptive 1x/1.5x Mode Switchover

♦ Single-Wire, Serial-Pulse Dimming (MAX8630X)

Independent On/Off/Dimming for Main and Sub

Linear—Full, 31/32nd, 30/32nd, … 1/32nd

♦ Direct-PWM Dimming (MAX8630W)

♦ 15, 18, 20, and 25mA Full-Scale Versions

♦ Low 0.1µA Shutdown Current

♦ Soft-Start Eliminates Inrush Current

♦ Output Overvoltage Protection

♦ Thermal-Derating Function Protects LEDs

♦ 14-Pin, 3mm x 3mm TDFN Package

MAX8630W/MAX8630X

125mA 1x/1.5x Charge Pumps for

5 White LEDs in 3mm x 3mm TDFN

________________________________________________________________ Maxim Integrated Products 1

1234567

13 12 11 10 9 8

LED2

LED1

LED3

LED5

C2P

C2N

C1N

GND

TDFN

3mm × 3mm

TOP VIEW

( ) ARE FOR MAX8630W

ENM (CPWM)

ENS (PWM)

C1P

OUT

MAX8630W

MAX8630X

LED4

Pin Configuration

Ordering Information

MAX8630X

1μF

GND

ENM

ENS

OUT

C1P C1N

MAIN

OUTPUT

SUB

C2P C2N

ENABLE MAIN

ON/OFF AND

DIMMING

ENABLE SUB

ON/OFF AND

DIMMING

INPUT

2.7V TO 5.5V

LED1

LED2

LED3

LED4

LED5

Typical Operating Circuit

19-0825; Rev 0; 5/07

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.

Ordering Information continued at end of data sheet.

EVALUATION KIT

AVAILABLE

PART

PIN-

PACKAGE

TOP

MARK

PKG

CODE

MAX8630WETD15+T

14 TDFN-14

(3mm x 3mm)

ADQ

T1433-2

Selector Guide appears at end of data sheet.

Note:

All devices are specified to operate over the -40°C to

+85°C operating temperature range.

+Denotes a lead-free package.

T = Tape and reel.

Summary of content (12 pages)

PAGE 1
9-0825; Rev 0; 5/07 KIT ATION EVALU E L B A AVAIL 125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN Features The MAX8630W/MAX8630X charge pumps drive up to 5 white LEDs with regulated constant current up to 125mA total. By utilizing adaptive 1x/1.5x charge-pump modes and very low-dropout current regulators, they achieve high efficiency over the full 1-cell Li+ battery input voltage range.
PAGE 2
MAX8630W/MAX8630X 125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN ABSOLUTE MAXIMUM RATINGS IN, OUT to GND.....................................................-0.3V to +6.0V C1N, C2N, ENM, CPWM, ENS, PWM to GND ............................................-0.3V to (VIN + 0.3V) LED_ to GND ............................................-0.3V to (VOUT + 0.3V) C1P, C2P to GND ...-0.3V to greater of (VOUT + 1V) or (VIN + 1V) OUT Short Circuit to GND ..........................................
PAGE 3
125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN (VIN = 3.6V, VGND = 0V, EN_ (PWM) = IN, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER CONDITIONS Open-Loop OUT Resistance TYP MAX 1x mode, (VIN - VOUT) / IOUT 0.8 1.5 1.5x mode, (1.5VIN - VOUT) / IOUT 3.2 7.2 Maximum OUT Current VIN ≥ 3.2V, VOUT = 3.9V OUT Short-Circuit Current Limit VOUT < 1.
PAGE 4
Typical Operating Characteristics (continued) (VIN = 3.6V, ENM = ENS = IN, TA = +25°C, unless otherwise noted.) INPUT RIPPLE VOLTAGE vs. SUPPLY VOLTAGE DRIVING 5 WHITE LEDs 100 ILED = 20mA 80 60 ILED = 8.125mA 40 15mA/LED 80 8mA/LED 60 40 27 26 2mA/LED 2.7 3.0 3.3 3.6 20 2.7 4.2 3.9 3.2 LED CURRENT MATCHING vs. INPUT VOLTAGE (2.5mA/LED) 2.7 3.1 2.60 3.9 4.3 2.50 2.40 2.30 2.20 120 100 80 TEMPERATURE DERATING 60 40 20 2.10 2.00 0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.
PAGE 5
125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN MAIN STARTUP AND SHUTDOWN WITH SUB ENABLED STARTUP AND SHUTDOWN MAX8630W/X toc12 MAX8630W/X toc11 5V/div 0 VENM AND VENS VENM 5V/div 0 VOUT 2V/div 2V/div VOUT 0 0 100mA/div 100mA/div IIN IIN 0 0 100mA/div 0 100mA/div IOUT IOUT 0 1ms/div 1ms/div STARTUP AND DIMMING LINE-TRANSIENT RESPONSE WITH MODE CHANGE (VIN = 3.8V TO 3.2V TO 3.
PAGE 6
125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN MAX8630W/MAX8630X Pin Description (continued) PIN FUNCTION MAX8630W 5 5 C2P Transfer Capacitor 2 Positive Connection. Connect a 1µF ceramic capacitor from C2P to C2N. 6 6 C1P Transfer Capacitor 1 Positive Connection. Connect a 1µF ceramic capacitor from C1P to C1N. 7 7 OUT Output. Connect a 1µF ceramic capacitor from OUT to GND. Connect OUT to the anodes of all the LEDs. In shutdown, OUT is pulled down by an internal 5kΩ resistor.
PAGE 7
125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN C1P 2.7V TO 5.5V 1μF C1N 1μF 1μF MAX8630X C1P 2.7V TO 5.5V OUT IN GND ENM OUT 1μF 1μF GND MAIN LED1 C1N IN LED2 ENABLE MAIN ON/OFF AND SERIAL DIMMING MAX8630W LED2 CPWM 0.1μF LED3 LED1 LED3 SUB LED4 ENABLE SUB ON/OFF AND SERIAL DIMMING LED4 DIRECT PWM SIGNAL LED5 ENS C2P C2N LED5 PWM C2P 1μF C2N 1μF Figure 1. Typical Applications Circuit with the MAX8630X C1P INPUT 2.7V TO 5.
PAGE 8
MAX8630W/MAX8630X 125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN Detailed Description The MAX8630_ charge pump drives up to 5 white LEDs (3 main LEDs and 2 sub LEDs) with regulated constant current for uniform intensity. By utilizing adaptive 1x/1.5x charge-pump modes and very low-dropout current regulators, it achieves 125mA guaranteed output-drive capability and high efficiency over the 1-cell Li+ battery input voltage range.
PAGE 9
125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN Overvoltage Protection If any LED fails as an open circuit, the corresponding VLED_ goes to 0V, and the output voltage is limited to about 5V by gating on/off the charge pump. In case any LED_ is floating or grounded, the MAX8630_ operates in the same overvoltage protection mode. To avoid overvoltage protection mode when using fewer than five LEDs, connect any unused LED_ to OUT.
PAGE 10
MAX8630W/MAX8630X 125mA 1x/1.
PAGE 11
125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN 6, 8, &10L, DFN THIN.EPS ______________________________________________________________________________________ 11 MAX8630W/MAX8630X Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.
PAGE 12
MAX8630W/MAX8630X 125mA 1x/1.5x Charge Pumps for 5 White LEDs in 3mm x 3mm TDFN Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) COMMON DIMENSIONS PACKAGE VARIATIONS SYMBOL MIN. MAX. PKG. CODE N D2 E2 e JEDEC SPEC b [(N/2)-1] x e A 0.70 0.80 T633-2 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF D 2.90 3.