AP3605_10 Datasheet, PDF (1/13 Pages) BCD Semiconductor Manufacturing Limited – 4-Channel Charge Pump LED Driver with Current Balancing and Wide Range PWM Dimming

Data Sheet
4-Channel Charge Pump LED Driver with Current Balancing and Wide Range PWM Dimming AP3605
General Description
Features
The AP3605 is a step-up DC/DC converter based on
1.5x charge pump current source, it is specially
designed for LED supplies in backlight display.
The AP3605 can provide constant current up to 20mA
for each LED, which is programmed by an external
resistor, so it has a total capability to provide 80mA for
4 LEDs. The chip has a good performance of LED
current matching and allows PWM brightness dim-
ming control. Additionally, high switching frequency
up to 1MHz enables the use of two small external
flying capacitors. Internal soft-start circuitry prevents
excessive inrush current during start-up.
The AP3605 supply voltage range is from 2.7V to
5.5V, ideally suited for applications powered by the Li-
ion battery.
· Regulated Output Current with ±3% Matching
· Regulated ±10% Output Current Source
· Drive up to 4 LEDs at 20mA Each
· Wide Operating Voltage Range: 2.7V to 5.5V
· High Efficiency up to 93%
· High Operating Frequency: 1MHz
· Built-in Soft-Start to Limit the Inrush Current
· LED Brightness Control through PWM and Ana-
log Signal
· PWM Dimming Frequency up to 50kHz
· Built-in Standby Mode to Get PWM Dimming
Duty Cycle Control Linearity
· Built-in OTSD (Over Temperature Shutdown)
Function to Protect the Device from Burn Out
Applications
The AP3605 is available in a 3mmx3mm QFN-3x3-16
tiny package. Its operating temperature range is -40^oC
to 85^oC.
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Mobile Phone
MP3, MP4
White LED Backlight in Mobile Phone, PDA
Jun. 2010 Rev. 1. 7
QFN-3x3-16
Figure 1. Package Type of AP3605
BCD Semiconductor Manufacturing Limited
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