ACE714C Datasheet, PDF (1/9 Pages) ACE Technology Co., LTD. – Max. 3MHz, Variable Frequency Step-up DC/DC Converter

ACE714C
Max. 3MHz, Variable Frequency Step-up DC/DC Converter
Description
The ACE714C veriable frequency step-up Converter drives white LEDs with a constant current to
provide backlight in cell phones, PDAs, and other handheld devices. It features allowing series
connection of the white LEDs so that the LED currents are identical for uniform brightness. An enable
input can be pulsed repeatedly to adjust LEDs brightness. The fast 3MHz operation frequency allows for
smaller capacitor and inductor. Fault condition protection uses cycle-by cycle current limiting to sense
maximum inductor current and over-voltage protection. The 0.2V low reference voltage minimized the
power loss across the current sense resistor.
The converter can operate from 2V to 6V, and capable of delivering maximum 250mA output current at
4-LEDs application with 3V input voltage is as low as 120uA. All of these features make ACE714C be
suitable for the portable devices, which are supplied by a single battery.
Features
 Up to 19V Output Voltage
 Wide Operation Range: 2V to 6V
 Maximum 3MHz Operating Frequency
 PWM Dimming Control
 Shutdown Current <1uA
 Current Limit Cycle-by-Cycle
 Low Current Sense Threshold: 200mV
 19V Over Output Voltage Protection
Application
 Compact Back Light Module
 Power Source for LED
 Constant Current Source
Typical Application
L1
Vin
10uH
D1
SS14
LED 1
LED 17
+ Cin
4.7uF
ON
OFF
Vin
LX
ACE714C OVP
CE
FB
GND
LED2
+ Cout
4.7uF
LED 3
LED 4
R1
Figure 1. ACE714C Typical Application Circuit
LED 18
LED 19
LED 20
R5
VER 1.2 1