AN2837 Datasheet, PDF (1/12 Pages) STMicroelectronics – Positive to negative buck-boost converter

AN2837
Application note
Positive to negative buck-boost converter
using ST1S03 asynchronous switching regulator
Abstract
The ST1S03 is a 1.5 A, 1.5 MHz adjustable step-down switching regulator housed in a
DFN6 package with internal power switch.
The device is a complete 1.5 A switching regulator with internal compensation that
eliminates the need for additional components. In this document the design of a polarity
inverting converter is discussed.
Figure 1. Polarity-inverting regulator using the ST1S03, 5 V_IN to - 5 V_OUT, 500 mA
C1
C4 _R3
V_IN= 5V
C2
R2
L1
R1
D1
C3
V_OUT= -5V
February 2009
Rev 1
1/12
www.st.com
12