ST ST1S30 User Manual

3 A, 1.5 MHz PWM step-down switching regulator

Features

■ 1.5 MHz fixed frequency PWM with current

control mode

■ 3 A output current capability

■ Typical efficiency: > 90%

■ 2 % DC output voltage tolerance

■ Two versions available: power good or inhibit

■ Integrated output over-voltage protection

■ Non switching quiescent current: (typ) 1.5 mA

over temperature range

■ R

■ Utilizes tiny capacitors and inductors

■ Operating junction temp. -25 °C to 125 °C

■ Available in DFN8 (4 x 4 mm) exposed pad

Description

The ST1S30 is a step-down DC-DC converter
optimized for powering low output voltage
applications. It supplies a current in excess of 3 A
over an input voltage range from 2.7 V to 6 V.

A high PWM switching frequency (1.5 MHz)
allows the use of tiny surface-mount components.

(typ) 100 mΩ

DSon

ST1S30

with synchronous rectification

DFN8 (4 x 4 mm)

Moreover, since the required synchronous
rectifier is integrated, the number of the external
components is reduced to minimum: a resistor
divider, an inductor and two capacitors. The
Power Good function continuously monitors the
output voltage. An open drain Power Good flag is
released when the output voltage is within
regulation. In addition, a low output ripple is
guaranteed by the current mode PWM topology
and by the use of low ESR SMD ceramic
capacitors. The device is thermally protected and
the output current limited to prevent damages due
to accidental short circuit. The ST1S30 is
available in the DFN8 (4 x 4 mm) package.

Table 1. Device summary

Order codes Package Note

ST1S30PUR

ST1S30IPUR INHIBIT version

1. Available on request.

September 2010 Doc ID 17927 Rev 1 1/11

(1)

DFN8 (4 x 4 mm)

PG version

www.st.com

11

Contents ST1S30

Contents

1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Typical application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2/11 Doc ID 17927 Rev 1

ST1S30 Diagram

1 Diagram

Figure 1. Schematic diagram

(*) Only for ST1S30I

(**) Only for ST1S30

Doc ID 17927 Rev 1 3/11

Pin configuration ST1S30

2 Pin configuration

Figure 2. Pin connections (top view)

ST1S30PUR

ST1S30IPUR

Table 2. Pin description

Pin n° Symbol Name and function

1 FB Feedback voltage

2 GND System ground

3 SW Switching pin

6V

IN_SW

7V

8 INH/PG Inhibit (INH) for ST1S30IPUR or Power Good (PG) for ST1S30PUR

Exposed pad GND

4, 5 NC Not internally connected. Can be connected to GND or left floating

Power supply for the MOSFET switch

Power supply for analog circuit

IN_A

To be connected to PCB ground plane for optimal electrical and thermal
performance

!-V

4/11 Doc ID 17927 Rev 1