Description

The SM8131B00B is a charge pump DC/DC converter designed for IC chips. It is a device that switches between ×1 and ×1.5 automatically. This converter is mainly used to extend battery life by detecting the LED drive current. It can control 1 to 6 lights of white LED that are connected in parallel through 6-channel LED drive current control circuits built-in in it. The LED drive current per channel is set up by external resistor, and by setting up SEL1/SEL2 pins, 6-channel of LED drive current control circuit can be divided to 2-groups, and input signal controlling allows ON/OFF and dimming per group.

Specifications and features

• Automatic charge pump switch between ×1 and ×1.5 according to the detection of the LED drive current, which extends battery life.
• Controlling 1 to 6 lights of white LED connected in parallel.
• Set up LED drive current value by external resistor (5kΩ:5mA/ch, 15kΩ:15mA/ch, 20kΩ:20mA/ch)
• Dividing 6-channel LED drive current control circuit to 2-groups by setting up SEL1/SEL2 pins (L/L = 6:0ch, L/H = 5:1ch, H/L = 4:2ch, H/H = 3:3ch).
• 2-wire input controlling (1-wire input controlling when SEL1/SEL2 pins are set to “LOW”).
• ON/OFF and brightness control by input signal controlling of EN1/EN2 pins.
• Supply voltage range:
• No-load current (IOUT= 0mA): 2.7 to 4.6V
• Load current (IOUT= 120mA): 3.3 to 4.6V
• Maximum output voltage: 4.2V (typ)
• Maximum output current: 120mA (typ)
• Quiescent current:
• Not-switching (×1 mode): 0.7mA (typ)
• Switching (×1.5 mode): 2.0mA (typ)
• Standby current (Power save mode): 0.01µA (typ)
• Operating frequency (×1.5 mode): 750kHz (typ)
• LED drive current accuracy (RSET = 20kΩ) :20mA ± 3%
• Input signal frequency for dimming (Duty = 50%) :150kHz (max)
• Package:20-pin QFN

Application Scenarios

This device is mainly used for IC chips.

Comparison

• The device automatically switches between ×1 and ×1.5 to extend battery life.
• The device has 6-channel LED drive current control circuits built-in for controlling 1 to 6 lights of white LED connected in parallel.
• It can control the LED drive current per channel by an external resistor and can be divided into 2-groups by setting up SEL1/SEL2 pins.
• The device has 2-wire input controlling and ON/OFF and brightness control by input signal controlling of EN1/EN2 pins.
• It has a low standby current (Power save mode): 0.01µA (typ).

• The device's input signal frequency for dimming is limited to 150kHz (max).
• The maximum output current is 120mA (typ), which may not be sufficient for certain applications.