TS19373

800mA Buck (Step-down) WLED Driver

3/7

Version: A09

Application Information

Pin Description

Pin

Function

Description

1

VIN

Input Voltage Supply pin

2

Ground

Ground Pin

3

Timing Capacitor

Timing capacitor oscillator input

4

Peak current sense input to monitor the voltage drop across an external

resistor to limit the peak current through the circuit

5

SW

Switching Pin. This is the internal Darlington switch collector

Inductor Selection

A 100uH inductor is recommended for most TS19373 applications. Although small size and high efficiency are major

concerns, the inductor should have low core losses at 180kHz and low DCR (copper wire resistance).

Diode Selection

Schottky diodes, with their low forward voltage drop and fast reverse recovery, are the ideal choices for TS19373

applications. The forward voltage drop of a Schottky diode represents the conduction losses in the diode while the

diode capacitance represents the switching losses. For diode selection, both forward voltage drop and diode

capacitance need to be considered. Schottky diodes with higher current ratings usually have lower forward voltage

drop and larger diode capacitance, which can cause significant switching losses at the 180kHz switching frequency of

the TS19373.

Capacitor Selection

For Input capacitor and timing capacitor are able to use small ceramic capacitor for most of TS19373 applications.

When AC input, to add a 100µF electric capacitor for input capacitor is recommended.