Philips ne5568 DATASHEETS

Philips Semiconductors Product specification

NE5568Switched-mode power supply controller

1

1994 Aug 31 853-0890 13721

DESCRIPTION

The NE5568 is a control circuit for use in switched mode power
supplies. It contains an internal temperature-compensated supply,
PWM, sawtooth oscillator, over-current sense latch, and output
stage. The device is intended for low cost SMPS applications where
extensive housekeeping functions are not required. The NE5568 is
a selected version of the NE5561.

FEATURES

•Micro-miniature (D) package

•Pulse width modulator

•Current limiting (cycle by cycle)

•Sawtooth generator

•Stabilized power supply

•Double-pulse protection

•Internal temperature-compensated reference

PIN CONFIGURATION

FE, N Packages

1

2

3

4 5

6

7

8

TOP VIEW

V

CC

V

Z

FEEDBACK

GAIN

CURRENT SENSE

GND

OUTPUT

R

T

, C

T

SL00437

Figure 1. Pin Configuration

APPLICATIONS

•Switch mode power supplies

•DC motor controller inverter

•DC/DC converter

ORDERING INFORMATION

DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #

8-Pin Plastic Dual In-Line Package (DIP) 0 to +70°C NE5568N SOT97-1
8-Pin Cerdip Dual In-Line Package (CERDIP) 0 to +70°C NE5568FE 0580A

BLOCK DIAGRAM

LATCH

OUTPUT

STABILIZED
SUPPLY

S

R

8.2V
2

PWM

SAWTOOTH
GENERATOR

REF
VOLTAGE

ERROR
AMP

FEEDBACK

GAIN

0.5V

CURRENT
SENSE

3

4

6

5

7

1 8

GND

–

+

+

–

V

CC

V

Z

V

CC

RT, C

T

SL00438

Figure 2. Block Diagram

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER RATING UNIT

V

CC

Supply voltage 18 V

I

OUT

Output current 40 mA
Output duty cycle 98 %

P

D

Max total power dissipation 0.75 W

T

A

Operating temperature range 0 to 70 °C

Philips Semiconductors Product specification

NE5568Switched-mode power supply controller

1994 Aug 31

2

DC ELECTRICAL CHARACTERISTICS

VCC=12V, TA=25°C, unless otherwise specified.

NE5568

SYMBOL

PARAMETER

TEST CONDITIONS

Min Typ Max

UNIT

Reference section

V

REF

Internal reference voltage TA=25°C 3.69 3.75 3.84 V

Over temperature 3.66 3.87 V

V

Z

Internal zener ref 7.8 8.2 8.8 V

Temperature coefficient of V

REF

IL=7mA ± 100 ppm/°C

Temperature coefficient of V

Z

± 200 ppm/°C

Oscillator section

f Frequency range Over temperature 50 100k Hz

Initial accuracy RT and CT Constant 5 %

Duty cycle range fo=20kHz 0 98 %

Current limiting

I

IN

Input current Pin 6=250mV TA=25°C -2 -10 µA

Over temp. -20 µA

Single pulse inhibit delay

Inhibit delay time for

20% overdrive at

I

OUT

=20mA 0.88 1.10 µs

I

OUT

=40mA 0.7 0.8 µs

Current limit trip level 0.400 0.500 0.600 V

Error amplifier

Open-loop gain 60 dB

Feedback resistor 10k Ω
BW Small-signal bandwidth 3 MHz
V

OH

Output voltage swing 6.2 V
V

OL

Output voltage swing 0.7 V

Output stage

I

OUT

Output current Over temperature 20 mA
V

CE

Saturation IC=20mA, over temperature 0.4 V

IC=40mA, over temperature 0.5 V

Supply voltage/current

I

CC

Supply current IZ=0, voltage-fed TA=25°C 10.0 mA

Over temp. 13.0 mA

V

CC

Supply voltage IS=10mA, current-fed 19.0 21.0 24.0 V

ICC=30mA, current-fed 20.0 30.0 V

Low supply protection

Pin 1 threshold 8.0 9.0 10.5 V

NOTES:

All curves and applications of NE5561 apply exactly