LM27952SD/NOPB.A中文资料德州仪器数据手册PDF规格书

1FEATURES

2• Drives up to 4 LEDs with up to 30mA each

• Regulated current sources with 0.2%(typ.)

matching

• 3/2x, 1x Gain transition based on LED VF

• Peak Efficiency Over 85%

• Input Voltage Range: 3.0V to 5.5V

• PWM Brightness Control

• Very Small Solution Size - NO INDUCTOR

• Fixed 750kHz Switching Frequency

• <1μA Shutdown Current

• 14-pin WSON Package: 4.0mm X 3.0mm X

0.8mm

APPLICATIONS

• White LED Display Backlights

• White LED Keypad Backlights

• General Purpose LED Lighting

DESCRIPTION

The LM27952 is a switched capacitor white-LED

driver capable of driving up to 4 LEDs with 30mA

through each LED. Its 4 tightly regulated current sinks

ensure excellent LED current and brightness

matching. LED drive current is programmed by an

external sense resistor. The LM27952 operates over

an input voltage range from 3.0V to 5.5V and requires

only four low-cost ceramic capacitors.

The LM27952 provides excellent efficiency without

the use of an inductor by operating the charge pump

in a gain of 3/2, or in a gain of 1. Maximum efficiency

is achieved over the input voltage range by actively

selecting the proper gain based on the LED forward

voltage requirements.