1 Features

• 2.5V to 5.5V input voltage

• 1.2V I/O Compatible for ADIM pin

• Integrated 280mΩ/600mΩ LS/HS switch FETs

• Up to 95% efficiency

• 130nA ultra-low shutdown current

• High-accuracy PWM controlled analog dimming

down to 0.1% dimming ratio

• Drives LED string up to 30V

• Switch current limit

– 1.8A for TPS923621

– 2.25A for TPS923622

• FCCM with 1.1MHz switching frequency options

• 200mV feedback voltage

• Internal compensation

• Protection Features

– Over-voltage protection

– Over-current protection

– Under-voltage lockout protection

– Thermal shutdown

2 Applications

• LCD back lighting

– Smartphone

– Thermostat

– HMI panel

– GPS personal navigation device

– Dashboard camera

• General illumination

– IP network camera

– Video doorbell

– Vacuum robot

3 Description

The TPS923621/2 is a synchronous boost LED

driver that integrates both low-side and high-side

switch FETs. It features an ultra-low 130nA shutdown

current. The TPS923621/2 can drive single or parallel

LED strings for LCD back lighting and general

illumination.

The feedback voltage is regulated to 200mV and

the output current is set by an external sensor

resistor, RSET, as shown in the Simplified Schematic.

During operation, a PWM signal applied to ADIM

pin adjusts the feedback voltage proportionally to the

PWM duty cycle, enabling precise analog dimming.

The TPS923621/2 supports PWM controlled analog

dimming with ratio as low as 0.1%, along with FCCM

operation, avoiding audible noises at the output since

current modulation remains purely analog.

The TPS923621/2 integrates over-voltage protection

that disables the power stage to prevent the output

voltage from exceeding the absolute maximum

voltage rating during LED open conditions. The

TPS923621/2 also provides over-current protection,

under-voltage lockout protection and thermal

shutdown protection.