TS5205

150mA Low Noise LDO Voltage Regulator

with Enable Function

4/7

Version: B07

Application Information

Enable Input

TS5205 series feature an active-high (>2V) 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 is

Input Capacitor Requirement

An input capacitor of 0.1uF or greater is recommended when the device is more than 10” away from the bulk AC

supply capacitance or when the supply is a battery.

Output Capacitor Requirement

The TS5205 series requires an output capacitor to maintain stability and improve transient response is necessary.

2.2uF minimum is recommended. Larger values improve the regulator’s transient response. The output capacitor

value may be increased without limit. The output capacitor should have an ESR (effective series resistance) less

than 5Ω and a resonant frequency above 1MHz. Ultra low ESR capacitors can cause a low amplitude oscillation on

the output and/or under damped transient response. Most of tantalum or aluminum electrolytic capacitors are

adequate; film types will work. Since many aluminum electrolytic have electrolytes that freeze at about –30

tantalums are recommended for operation below –25

required for output stability. The capacitor can be reduced to 0.47uF for current below 10mA or 0.33uF for currents

Reference Bypass Capacitor

The star up speed of the TS5205 is inversely proportional to the size of the reference bypass capacitor. Applications

No Load Stability

The TS5205 series will remain stable and in regulation with no load, unlike many other voltage regulators. This is

especially important in CMOS RAM keep alive applications.

Adjustable Regulator Design

The adjustable regulator versions can be adjusted to a specific output voltage by using two external resistors to

programming the output voltage anywhere between 1.25 and the 8V maximum operating rating of the family.

Two resistors are used. Resistors can be quite large up to 470kΩ, because of the very high input impedance and low

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

A capacitor from Adjust to Ground provides greatly improved noise performance.

2.2uF

on

off

EN

R1

R2

470pF

TS5205CX5

(Adjustable output range up to 8V)