EVAL5972D STMicroelectronics

L5972D 2A switch step down switching regulator Features 2A internal switch Operating input voltage from 4.4V to 36V Output voltage adjustable from 1.235V to 35V SO8 Low dropout operation: 100% duty cycle 250kHz Internally fixed frequency Description Voltage feedforward Zero load current operation The L5972D is a step down monolithic power switching regulator with a minimum switch current Internal current limiting limit of 2A so it is able to deliver more than 1.5A Protection against feedback disconnection DC current to the load depending on the Thermal shutdown application conditions. The output voltage can be set from 1.235V to 35V. Applications The device uses an internal P-Channel D-MOS Consumer: STB, DVD, TV, VCR, car radio, transistor (with a typical Rdson of 250m) as LCD monitors switching element to minimize the size of the external components. Networking: XDSL, modems, DC-DC modules Computer: printers, audio/graphic cards, An internal oscillator fixes the switching frequency optical storage, hard disk drive at 250kHz. Industrial: changers, car battery, DC-DC Having a minimum input voltage of 4.4V only, it is converters particularly suitable for 5V bus, available in all computer related applications. Pulse by pulse current limit with the internal frequency modulation offers an effective constant current short circuit protection. Figure 1. Test application circuit L1 33H VOUT=3.3V VIN = 4.4V to 35V VCC OUT 1 8 D1 R1 L5972D STPS2L40U COMP 5.6K C2 C1 4 5 100F 10F 6 2 3 7 C4 FB 10V 35V 22nF CERAMIC GND R2 C3 3.3K R3 220pF 4.7K D03IN1436 October 2007 Rev 10 1/15 www.st.com 15Contents L5972D Contents 1 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6 Application ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8 Order code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2/15