Advanced Monolithic Systems, Inc.

www.advanced-monolithic.com

Phone (925) 443-0722

Fax (925) 443-0723

AMS4106

DETAIL DESCRIPTION and GUIDELINES (continued)

Reference Circuit

A high precision bandgap is used giving a low TC and good supply rejection. The output is attenuated to give a reference

voltage of 0.600V making it suitable for very low output voltage applications.

COMPENSATION

The converter is of the current mode topology considered simplifying the selection of compensation components. For most

voltages this simple formula is a good starting point

Ccomp = 15e-9/Vout for L = 10e-6 and Cout = 44e-6

Ccomp is proportional to the output inductors and output capacitor

Rcomp = 18e3/Vout

Output capacitor Cout, is a function of the maximum current and ripple required.

Multiple capacitors may be required to give the optimum ripple and transient response.

The stability is not that critical for varying Cout, however to prevent OCP during fast load transients Ccomp, has to be increased

in proportion to Cout.

The current gain of the output stage is approximately 6A/volt

The running transconductance output current is

Sourcing current

95 µA

Sinking current

85 µA

This equates to about 600e-6 mohs

For best transient response each application is unique and these components should only be used as a starting point.