Sales Information

Phone:(425) 353-3010

Fax: (425) 353-4030

SVRGA0508S - 5.0

E-mail: vptsales@vptpower.com

Web: www.vptpower.com

Page 6

SVRGA0508S Series

6.0 TECHNICAL NOTES

Please note that many of these functions are also demonstrated in detail on the VPT website in the

form of technical video labs.

6.1 GENERAL INFORMATION

6.1.1 Topology Description

The SVRGA0508S Series is a non-isolated, fixed-frequency, radiation-hardened, synchronous buck converter. It operates from a 5 V

input and provides a stepped-down, precisely regulated, programmable output voltage at very-high efficiency. The SVRGA0508S is

optimized for low voltage point of load applications.

6.1.2 External Components

The SVRGA0508S Series has internal input and output capacitors. For best performance under transient conditions, an additional

220 µF tantalum input decoupling capacitor is recommended. The SVRGA0508S is stable with no load capacitance. However for

optimum performance under worst-case conditions, a minimum output capacitance of 220 µF is assumed. This minimum output

capacitance requirement is usually met with distributed load capacitance. Additional output capacitance is allowed up to the maximum

listed in Section 3.2.

6.1.3 Source Impedance

The impedance of the 5 V input source can interact with the point of load converter and can affect performance. High source

impedance is often caused by a long input cable or other components added in series with the input. In some cases, additional input

capacitance will be needed to stabilize the system.

6.2 FUNCTION DESCRIPTIONS

6.2.1 On/Off Control (Inhibit)

The INH (Inhibit) pin is a control pin referenced to COM. The INH pin must be driven

using an open-collector or open-drain configuration. Pulling the INH pin low disables

the converter output. Leaving INH open enables the output, allowing the converter to

operate normally. The pin must be pulled below 1.5 V to disable the output. An

optional capacitor from INH to INCOM may be used to delay turn-on. The INH pin

should be left open if not used.

2

COM

3

INH

1

+VIN

OPTIONAL

CAPACITOR

47K