SEME LAB IP1844 Technical data

查询IP1844供应商

SEME

LAB

TOP VIEW

IP1844 SERIES
IP1845 SERIES

COMP

V

FB

I

SENSE

RT/C

1

2

3

4

T

8

V

REF

7

V

CC

6

OUTPUT

5

GROUND

J Package – 8 Pin Ceramic DIP

N Package – 8 Pin Plastic DIP

D-8 Package – 8 Pin Plastic (150) SOIC

TOP VIEW

1

COMP

2

N/C N/C

14

V

REF

13

FEATURES

• Guaranteed ±1% reference voltage tolerance

• Guaranteed ±10% frequency tolerance

• Low start–up current (<500 mA)

• Under voltage lockout with hysteresis

3

V

FB

4

N/C

5

I

SENSE

6

N/C

7

R

T/CT

D-14 Package – 14 Pin Plastic (150) SOIC

12

V

11

V

10

OUTPUT

9

GROUND
POWER

8

GROUND

CC

C

• Output state completely defined for all supply
and input conditions

• Interchangeable with UC1844 and UC1845
series for improved operation

• 500kHz Oscillator operation
250kHz Output operation

Order Information

Part J–Pack N–Pack D–8 D–14 Temp.
Number 8 Pin 8 Pin 8 Pin 14 Pin Range

IP1844 ✔ -55 to +125°C
IP2844 ✔✔✔✔-25 to +85°C
IP3844 ✔✔✔✔0 to +70°C
IP1845 ✔ -55 to +125°C
IP2845 ✔✔✔✔-25 to +85°C
IP3845 ✔✔✔✔0 to +70°C

CURRENT MODE

REGULATING

PULSE WIDTH

MODULATORS

Note:

To order, add the package identifier to the
part number.

eg. IP1844D–14

IP3845J

ABSOLUTE MAXIMUM RATINGS (T

V

CC

Supply Voltage (low impedance source)

= 25°C unless otherwise stated)

case

(ICC< 30mA)

I

O

Output Current
Output Energy (capacitive load)
Analog Inputs (pins 2 and 3)
Error Amp Output Sink Current

P

P

P

T
T

D

D

D

STG
L

Power Dissipation T
Derate @ T

amb

> 50°C

Power Dissipation T
Derate @ T

amb

> 50°C

Power Dissipation T
Derate @ T

case

> 25°C

= 25°C J, N Packages

amb

= 25°C D Package

case

= 25°C J, N Packages

case

Storage Temperature Range
Lead Temperature (soldering, 10 seconds)

Semelab plc. Telephone [phone]. Telex: 341927. Fax [phone].

+30V

Self limiting

±1A

5µJ

–0.3V to +V

10mA

1W

10mW/°C

725mW

7.25mW/°C
2W

16mW/°C

–65 to 150°C

+300°C

CC

Prelim. 2/95

IP1844 SERIES

Values in brackets are for IP1845 series.

3.6V

ERROR

AMP

OSCILLATOR

2R

R

1V

R

S

PWM

LATCH

CURRENT
SENSE
COMPARATOR

16V

(8.4V)

6V

(0.5V) 2.5V

UNDER–VOLTAGE

LOCKOUT

ENABLE

REFERENCE
REGULATOR

5V

INTERNAL

BIAS

34V

REG

R

S

V STATUS

LATCH

REF

T

Q

TOGGLE

FLIP

FLOP

PIN NUMBERS
1st Number
2nd Number

– N, J and 8 Pin D Packages
– 14 Pin D Package.

C

OMP

G

ND

V

CC

I

SENSE

V

FB

/CR

TT

OUTPUT

POWER
GROUND

V

REF

V

C

3/5

5/9

7/12

2/3

1/1

4/7 6/10

7/11

5/8

8/14

SEME

IP1845 SERIES

LAB

DESCRIPTION

The IP1844 and IP1845 series of switching regulator control circuits contain all the functions necessary to

implement off-line, current mode switching regulators, using a minimum number of external parts.

Functions included are voltage reference, error amplifier, current sense comparator, oscillator, totem-pole output
driver and under-voltage lockout circuitry. In addition there is a toggle flip-flop which blanks the output on every
second clock pulse, thereby ensuring that the duty cycle never exceeds 50%.

Although pin compatible with the UC1844 and UC1845 series, SEMELAB has incorporated several improvements
in the IP1844 and IP1845 series allowing tighter and more complete specification of electrical performance .

BLOCK DIAGRAM

RECOMMENDED OPERATING CONDITIONS

V

CC

I

O

Supply Voltage
Output Current
Analog Inputs (pins 2 and 3)
Error Amp Output Sink Current

Operating Ambient Temperature Range IP2844 , IP2845

Semelab plc. Telephone [phone]. Telex: 341927. Fax [phone].

IP1844 , IP1845

IP3844 , IP3845

≤ 30V

0 to ±200mA

–0.3V to 3V

0 to 2mA

–55 to 125°C
–25 to 85°C

0 to 70°C

Prelim. 2/95