3.0A Ultra Low Dropout Linear Regulator

TJ3966

Aug. 2010 - Rev. 1.7.1

- 8

-

HTC

APPLICATION INFORMATION

Output Adjustment (Adjustable Version)

An adjustable output device has output voltage range of 1.145V to 5.0V. To obtain a desired output

voltage, the following equation can be used with (R1+R2) resistor range of 1kΩ to 100kΩ

⎟

⎠

⎞

⎜

⎝

⎛

−

=

1

1.145

V

R1

R2

OUT

SENSE Pin

In applications where the regulator output is not very close to the load, the TJ3966 can provide better

remote load regulation characteristics using the SENSE pin. TJ3966 regulates the voltage at the output

pin. Hence, the voltage at the remote load will be lower than the voltage at the output pin as a value of

the voltage drop across the trace series resistance. If the sense option pin is not required, the sense pin

at the remote load because the TJ3966 regulates the voltage at the sense pin when the sense option pin

is used.

Output Capacitor

The TJ3966 requires a proper output capacitance to maintain stability and improve transient response

over current. The ESR of the output capacitor within the limits of 0.5Ω to 10Ω is required. A minimum

capacitance value of 22µF of tantalum or aluminum electrolytic capacitor is recommended. In a case of

ceramic capacitor, a minimum capacitance value of 10µF is required and additional resistance of

minimum 1Ω should be added with the output capacitor in series to maintain its minimum ESR. The

resistance and capacitance have to be varied upon the load current.

VOUT

ADJ

GND

R2

R1

22µF

OUTPUT

+

-

VOUT

ADJ

GND

R2

R1

10µF

OUTPUT

Additional Resistance