TS1916

1.7A Boost WLED Driver

5/10

Version: A14

Application Information

Setting the ILED Current

Application circuit item shows the basic application circuit with TS1916 adjustable output version. The external

resistor sets the LED output current according to the following equation:

Part No.

R3

TS1916

20mA

10Ω

4mW

350mA

0.571Ω

70mW

Over Voltage Protection

Under Voltage Lockout (UVLO)

To avoid mis-operation of the device at low input voltages an under voltage lockout is included that disables the

device, if the input voltage falls below (2.25V-100mV).

Input Capacitor Selection

The input capacitor reduces the surge current drawn from the input and switching noise from the device. The input

capacitor impedance at the switching frequency shall be less than input source impedance to prevent high

frequency switching current passing to the input. A low ESR input capacitor sized for maximum RMS current must

be used. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and

small temperature coefficients. A 4.7µF ceramic capacitor for most applications is sufficient. For a lower output

power requirement application, this value can be decreased.

Output Capacitor Selection

The output capacitor is required to keep the output voltage ripple small and to ensure regulation loop stability. The

output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or X7R

dielectrics are recommended due to their low ESR and high ripple current. A 1µF ceramic capacitors works for most

of the applications. Higher capacitor values can be used to improve the load transient response.