AN1723 Datasheet, PDF (1/24 Pages) STMicroelectronics – Designing with the L5973AD high efficiency DC-DC converter

AN1723
Application note
Designing with the L5973AD high efficiency DC-DC converter
Introduction
The L5973AD is a step-down monolithic power switching regulator capable of delivering up
to 2 A at output voltages from 1.235 V to 35 V. The operating input voltage ranges from
4.4 V to 36 V. It is realized in BCDV technology and the power switching element is realized
by a P-channel D-MOS transistor. It doesn’t require a bootstrap capacitor, and the duty cycle
can range up to 100%. An internal oscillator fixes the switching frequency at 500 kHz which
minimizes the LC output filter. The synchronization pin is available in case a higher
frequency is required. Pulse-by-pulse and frequency foldback overcurrent protection offer an
effective short-circuit protection. Other features include voltage feed-forward, protection
against feedback disconnection, and inhibit and thermal shutdown. The device is housed in
a HSOP8 package with exposed pad that helps to reduce the thermal resistance junction to
ambient (R_Thj-a) down to approximately 40 °C/W.
Figure 1. EVAL5973AD demonstration board
June 2012
Doc ID 9553 Rev 4
1/24
www.st.com