TS39154

1.5A Ultra Low LDO with Enable

4/7

Version: D08

Application Information (Continue)

Input Capacitor Requirement

An input capacitor of 1uF or greater is recommended when the device is more than 4” away from the bulk AC supply

capacitance or when the supply is a battery. Small, surface mount, ceramic chip capacitors can be used for bypassing.

Larger values will help to improve ripple rejection by bypassing the input to the regulator, further improving the integrity

of the output voltage.

Minimum Load Current

The TS39154 is specified between finite loads. If the output current is too small leakage currents dominate and the

output voltage rises. A 10mA minimum load current is necessary for proper regulation.

Adjustable Regulator Design

The TS39154 is allowed to programming the output voltage anywhere between 1.25 and the 16V maximum operating

rating of the family.

Two resistors are used. Resistors can be quite large up to 1MΩ, because of the very high input impedance and low

bias current of the sense comparator, the resistor values are calculated by:

widely varying load currents may scale the resistors to draw the minimum load current required for proper operation.

Enable Input

TS39154 feature an active-high enable (EN) input that allows ON/OFF control of the regulator. Current drain reduces

to “zero” when the device is shutdown, with only micro-amperes of leakage current. The EN input has TTL/CMOS

maximum supply voltage.

Table 1: Resistor select for output voltage setting

R1

R2

5V

470kΩ

155kΩ

3.3V

470kΩ

290kΩ

2.5V

470kΩ

460kΩ

1.8V

210kΩ

470kΩ

1.5V

100kΩ

470kΩ