SANYO STK732C Datasheet

Thick Film Hybrid IC

Ordering number : EN4533B

61096HA (OT)/82793YO (OT)No. 4533-1/6

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN

15 V Single Output MOS Chopper Regulator

STK732C

Overview

The STK732C is a chopper type step-down dedicated
15 V single output regulator that uses a power MOSFET
as its switching element. The STK732C covers the 2 A
and higher current regions, regions that are difficult to
handle with three terminal step-down regulators. As
compared with earlier chopper regulator products that
used bipolar transistors, the efficiency of the STK732C
has been further improved by the adoption of MOSFET
technology, and use of the STK732C enables further
miniaturization and increased performance in the end
product since it corresponds to the adoption of a
dedicated switching controller IC. Furthermore, due to
the development of a unique MOS drive circuit, the
STK732C can be used with a single power supply input.
The STK732C can prove useful when standardizing and
rationalizing power supply circuit design, since it can
handle a wide range of power supply circuits in a
number of applications, either as the secondary side
regulator in a switching power supply or as the output
regulator following AC transformer rectification.

Applications

• Power supplies in printers and other office equipment

• Power supplies in robots and other factory automation
related equipment

• Power supplies in VCRs and other consumer products

• Secondary side regulators in switching power supplies

Features

• IMST substrate (insulated metal substrate technology)

• High efficiency realized by the adoption of MOSFET
technology.

• An auxiliary drive power supply is no longer required
due to the development of a unique NMOS FET drive
circuit. This means that the STK732C can be used
with a single power supply, thus allowing
simplification of the input system.

• Built-in reverse going linear overload characteristic
curve overcurrent protection circuit

• Ground line handling is eased even in multi-output
power supply structures due to placement of the
overcurrent detection resistor on the plus line.

• The STK732C’s separate excitation oscillator
structure provides high stability in the switching
frequency.

• A built-in cutoff function allows an external signal to
switch the output on and off.

• The STK732C’s switching operating frequency is set
at 85 kHz, which minimizes beating when used in a
multiple output structure with STK730 type (5 V
output, 125 kHz) products.

Package Dimensions

unit: mm

4137

[STK732C]

STK732C

Specifications

Maximum Ratings at Ta = 25°C

Parameter Symbol Condition Rating Unit

Maximum DC input voltage V

IN

(DC) max 60 V

Maximum output current I

O

max 5/10 pk A

Thermal resistance

θj-c 3.5 °C/W
Junction temperature Tj max 150 °C
Operating substrate temperature Tc max 105 °C
Storage temperature T

stg

–30 to +105 °C

Electrical Characteristics at Ta = 25°C, for the specified test circuit

Rating

Parameter Symbol Condition

min typ max

Unit

Output voltage setting V

O

VIN(DC) = 35 V, IO= 1 A 14.7 15.0 15.3 V

Ripple voltage Vrp V

IN

(DC) = 35 V, IO= 1 A 25 mVrms

Input regulation Reg-IN V

IN

(DC) = 20 to 45 V, IO= 1 A 20 mV/V

Load regulation Reg-L V

IN

(DC) = 35 V, IO= 0.5 to 5 A 40 mV/A

Overcurrent protection start current I

OCP

VIN(DC) = 35 V 10 A

Efficiency η V

IN

(DC) = 35 V, IO= 2.5 A 90 %

Operating frequency f V

IN

(DC) = 35 V, IO= 1 A 85 kHz

Output voltage temperature coefficient

T

CVO

VIN(DC) = 35 V, IO= 1 A 0.01 %/°C

Cutoff voltage

Voff

Output on 3 20 V

(Pin 12 input voltage)

Output off 0 0.8 V

Peak Current

Block Diagram

No. 4533-2/6