Rainbow Electronics MAX8645Y - Manual

EVALUATION KIT
AVAILABLE
General Description
The MAX8645X/MAX8645Y charge pumps drive up to
eight white LEDs with regulated constant current for uni-
form intensity. The main group of LEDs (M1–M6) can be
driven up to 30mA per LED for backlighting. The flash
group of LEDs (F1 and F2) is independently controlled
and can be driven up to 200mA per LED (or 400mA total).
Two 200mA LDOs are on-board to provide power for
camera functions. The LDOs’ output voltages are pin pro-
grammable to meet different camera-module require-
ments. The MAX8645X and MAX8645Y differ only in LDO
output voltages. By utilizing adaptive 1x/1.5x/2x charge-
pump modes and very-low-dropout current regulators,
the MAX8645X/MAX8645Y achieve high efficiency over
the full 1-cell lithium-battery voltage range. The 1MHz
fixed-frequency switching allows for tiny external compo-
nents, and the regulation scheme is optimized to ensure
low EMI and low input ripple.
The MAX8645X/MAX8645Y are available in a 28-pin TQFN,
4mm x 4mm (0.8mm max height) lead-free package.
Applications
Camera Phones and Smartphones
Backlighting and Flash
PDAs, Digital Cameras, and Camcorders
Features
♦ Power Up to Eight LEDs
Up to 30mA/LED Drive for Backlight
Up to 400mA Total Drive for Flash
♦ Two Internal Low-Noise 200mA LDOs
♦ 94% Max/85% Avg Efficiency (P
LED /P BATT ) over Li+
Battery Discharge
♦ 0.2% Typical LED Current Matching
♦ Adaptive 1x/1.5x/2x Mode Switchover
♦ Flexible Brightness Control
Single-Wire, Serial-Pulse Interface (32 Steps)
2-Bit Logic (Three Levels)
♦ Thermal T
A Derating Function
♦ Low Input Ripple and EMI
♦ 2.7V to 5.5V Supply Voltage Range
♦ Soft-Start, Overvoltage, and Thermal-Shutdown
Protection
♦ 28-Pin TQFN, 4mm x 4mm Package
MAX8645X/MAX8645Y
1x/1.5x/2x White LED Charge Pumps with
Two LDOs in 4mm x 4mm TQFN
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-3978; Rev 3; 12/06
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.
PART TEMP RANGE
PIN-
PACKAGE PKG
CODE
MAX8645XETI+ -40°C to +85°C
28 TQFN-EP
4mm x 4mm
T2844-1
MAX8645YETI+ -40°C to +85°C
28 TQFN-EP
4mm x 4mm
T2844-1
Pin Configuration appears at end of data sheet.
MAIN ON/OFF
AND DIMMING
MAX8645X
MAX8645Y
1 μF
10 μF
0.01 μF
10 μF
PIN
IN
PGND
GND
P1
P2
OUT
MAIN FLASH
OUTPUT
UP TO 580mA
1 μF 1 μF
LDO1
LDO2
C2P C2N
1 μF
C1P C1N
REF SETM SETF
CAMERA
MODULE
DUAL-LDO
VOLTAGE
SELECTION
INPUT
2.7V TO 5.5V
ENM2
ENM1
ENF
ENLDO
M1
M2
M3
M4
M5
M6
F1
F2
FLASH ON/OFF
DUAL-LDO ON/OFF
Typical Operating Circuit
EP = Exposed paddle.
+Denotes a lead-free package.