Datasheet IP3843N, IP3843J, IP3843D-8, IP3843D-14, IP3843D Datasheet (Semelab Plc)

IP1842 SERIES
IP1843 SERIES

Prelim.3/00

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E-mail: [e-mail]

Website: http://www.semelab.co.uk

CURRENT MODE

REGULATING

PULSE WIDTH

MODULATORS

FEATURES

• Guaranteed ±1% reference voltage tolerance

• Guaranteed ±10% frequency tolerance

• Low start–up current (<500

mmmmA)

• Under voltage lockout with hysteresis

• Output state completely defined for all supply
and input conditions

• Interchangeable with UC1842 and UC1843
series for improved operation

• 500kHz operation

V

CC

Supply Voltage (low impedance source)

(ICC< 30mA)

I

O

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

P

D

Power Dissipation T

amb

= 25°C

Derate @ T

amb

> 50°C

P

D

Power Dissipation T

case

= 25°C

Derate @ T

case

> 25°C

T

STG

Storage Temperature Range

T

L

Lead Temperature (soldering, 10 seconds)

+30V

Self limiting

±1A

5mJ

–0.3V to +V

CC

10mA

1W

10mW/°C

2W

24mW/°C

–65 to 150°C

+300°C

ABSOLUTE MAXIMUM RATINGS (T

case

= 25°C unless otherwise stated)

TOP VIEW

J Package – 8 Pin Ceramic DIP

N Package – 8 Pin Plastic DIP

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

1

2

3

4

8

7

6

5

COMP

V

REF

GROUND

OUTPUT

RT/C

T

V

CC

I

SENSE

V

FB

TOP VIEW

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

COMP

V

REF

GROUND

OUTPUT

1

2

3

4

POWER
GROUND

5

6

7

14

13

12

11

10

9

8

N/C

R

T/CT

I

SENSE

N/C

N/C N/C

V

CC

V

FB

V

C

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

IP1842 ✔ -55 to +125°C
IP2842 ✔✔✔✔-25 to +85°C
IP3842 ✔✔✔✔0 to +70°C
IP1843 ✔ -55 to +125°C
IP2843 ✔✔✔✔-25 to +85°C
IP3843 ✔✔✔✔0 to +70°C

Order Information

Note:

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

eg. IP1842J

IP3843D-14

IP1842 SERIES
IP1843 SERIES

Prelim.3/00

Semelab plc. Telephone [phone]. Fax [phone].

E-mail: [e-mail]

Website: http://www.semelab.co.uk

DESCRIPTION

The IP1842 and IP1843 series of switching regulator control circuits contain all the functions necessary to
implement off–line, current mode switching regulators, using a minimum number of exter nal parts. Functions
included are voltage reference, error amplifier, current sense comparator, oscillator, totem pole output driver and
under-voltage lockout circuitry.

Although pin compatible with the UC1842 and 1843 series, SEMELAB has incorporated several improvements in
the IP1842 and IP1843 series allowing tighter and more complete specification of electrical performance.

BLOCK DIAGRAM

Values in brackets are for IP1843 series.

3.6V

ERROR

AMP

OSCILLATOR

2R

R

1V

R

S

PWM

LATCH

CURRENT
SENSE
COMPARATOR

16V

(8.4V)

6V

(0.5 V) 2.5 V

UNDER–VOLTAGE

LOCKOUT

ENABLE

REFERENCE
REGULATOR

5V

INTERNAL

BIAS

34V

REG

R

S

V STATUS

LATCH

REF

OUTPUT

V

REF

C

OMP

G

ND

V

CC

I

SENSE

V

FB

/CR

TT

POWER
GROUND

V

C

PIN NUMBERS
1st Number
2nd Number

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

3/5

5/9

7/12

2/3

1/1

4/7

6/10

7/11

5/8

8/14

V

CC

Supply Voltage

1

I

O

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

IP1842 , IP1843

Operating Ambient Temperature Range IP2842 , IP2843

IP3842 , IP3843

£

30V

0 to ±200mA

–0.3V to 3V

0 to 2mA

–55 to 125°C
–25 to 85°C

0 to 70°C

Notes:

1. Lower limit set by under voltage lockout specification.

RECOMMENDED OPERATING CONDITIONS

NOTES

1. Test Conditions unless otherwise stated:
V

CC

= 15V* , RT= 10kW, CT= 3.3nF , f = 52kHz.

*Adjust V

CC

above start threshold before setting at required level.

All specifications apply over the full operating temperature range
unless otherwise stated. (See Ordering Information for further details).

IP1842 SERIES
IP1843 SERIES

Prelim.3/00

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4.90 5.00 5.10
620
625

0.2 0.4

4.82 5.18

50

525

30 80 160

47 52 57

0.2 1
5

1.7

8.3
8

2.42 2.50 2.58
–0.3 –2

65 90

0.7 1
60 70

26

–0.5 –0.8

4.6 4.8

0.7 1.1

4.95 5.00 5.05
620
625

0.2 0.4

4.90 5.10

50

525

30 80 160

47 52 57

0.2 1
5

1.7

8.3
8

2.45 2.50 2.55
–0.3 –1

65 90

0.7 1
60 70

26

–0.5 –0.8

4.6 4.8

0.7 1.1

IP1842/IP1843 IP3842
IP2842/IP2843 IP3843

Parameter Test Conditions Min. Typ. Max. Min. Typ. Max. Units

Output Voltage
Input Regulation
Output Regulation

Temperature Stability

Total Output Variation
Output Noise Voltage
Long Term Stability
Output Short Circuit
Current

Frequency
Voltage stability
Temperature Stability
Amplitude

Discharge Current

Input Voltage
Input Bias Current
Open Loop Voltage
Gain
Unity Gain Bandwidth
Supply Voltage
Rejection
Output Sink Current
Output Source Current
V

OUT

High

V

OUT

Low

I

O

= 1mA TJ= 25°C

V

CC

= 12V to 25V

I

O

= 1mA to 20mA

Line, Load, Temp
f = 10Hz to 10kHz T

J

= 25°C

T

J

= 125°C @ 1000Hrs

V

REF

= 0

T

J

= 25°C

V

CC

= 12V to 25V

D

T

A

= Min to Max

V

PIN4

Peak to Peak

T

J

= 25°C

D

T

A

= Min to Max

V

PIN1

= 2.5V

V

O

= 2V to 4V

V

CC

= 12V to 25V

V

PIN2

= 2.7V V

PIN1

= 1.1V

V

PIN2

= 2.3V V

PIN1

= 4.6V

V

PIN2

= 2.3V RL= 15k

W

V

PIN2

= 2.7V RL= 15k

W

V

mV

mV

°C

V

m

V

mV
mA

kHz

%
%

V

mA

%

V

m

A

dB

MHz

dB

mA

V

ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated)

REFERENCE SECTION

OSCILLATOR SECTION

ERROR AMP SECTION

IP1842/IP1843 IP3842
IP2842/IP2843 IP3843

Parameter Test Conditions Min. Typ. Max. Min. Typ. Max. Units

2.85 3 3.15

0.911.1
60 70

–2 –10

200 400

0.1 0.4

1.5 2.2
13 13.5
12 13.5

50 150
50 150

0.7 1.1

14.5 16 17.5

7.8 8.4 9

8.5 10 11.5
7 7.6 8.2

0.3 0.5
11 15
14 17

30 34 40

2.85 3 3.15

0.911.1
60 70

–2 –10

200 400

0.1 0.4

1.5 2.2
13 13.5
12 13.5

50 150
50 150

0.7 1.1

15 16 17

7.8 8.4 9
91011
7 7.6 8.2

0.3 0.5
11 15
14 17

30 34 40

Gain
Maximum Input Signal
Supply Voltage
Rejection
Input Bias Current
Delay to Output

Output Low Level

Output High Level

Rise Time
Fall Time
UVLO Saturation

Upper Threshold
(V

CC

)
Lower Threshold
(V

CC

)

Start–up Current
Operating Supply
Current
V

CC

Zener Voltage

See Notes 2,3
V

PIN1

= 4.6V (Note 2)

V

C

= 12V to 25V

I

SINK

= 20mA

I

SINK

= 200mA

I

SOURCE

= 20mA

I

SOURCE

= 200mA

C

L

= 1nF TJ= 25°C

C

L

= 1nF TJ= 25°C

V

CC

= 6V IL= 1mA

1842 Series
1843 Series
1842 Series
1843 Series

V

PIN2

= 0V 1842 Series

V

PIN3

= 0V 1843 Series

I

CC

= 25mA

V/V

V

dB

m

A

ns

V

V

ns

V

V

V

mA
mA

V

NOTES

1. Test Conditions unless otherwise stated:
V

CC

= 15V* , RT= 10kW, CT= 3.3nF , f = 52kHz.

*Adjust V

CC

above start threshold before setting at

required level.

All specifications apply over the full operating temperature
range unless otherwise stated.
(See Ordering Information for further details).

2. Parameter measured at trip point of latch with
V

PIN2

= 0V

3. Gain defined as:

D

V

PIN1

A =

D

V

PIN3

0 £V

PIN3

£

0.8

IP1842 SERIES
IP1843 SERIES

Prelim.3/00

Semelab plc. Telephone [phone]. Fax [phone].

E-mail: [e-mail]

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ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated)

CURRENT SENSE SECTION

OUTPUT SECTION

UNDER–VOLTAGE LOCKOUT SECTION

TOTAL STANDBY CURRENT

tc»

0.55 RTC

T

td»

RTC

T

Rn

1

Resultant frequency f =

(t

c

+ td)

For R

T

> 5kW,

1.8

Resultant frequency f

»

(R

TCT

)

Oscillator timing capacitor CTis charged by V

REF

through RTand discharged by an internal current source.
During the discharge time, the internal clock signal
blanks the output to the low state. Selection of R

T

and

C

T

therefore determines both oscillator frequency and
maximum duty cycle. Charge and discharge times are
determined by the formulae:

.0063 RT– 2.3

.0063 – 4

( )

IP1842 SERIES
IP1843 SERIES

Prelim.3/00

Semelab plc. Telephone [phone]. Fax [phone].

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Open–Loop Laboratory Test Fixture

APPLICATIONS INFORMATION

High peak current associated with capacitive loads necessitate careful grounding techniques. Timing and bypass capacitors should
be connected close to pin 5 in a single point ground. The transistor and 5K potentiometer are used to sample the oscillator wave
form and apply an adjustable ramp to pin 3.

1

2

3

4

8

7

6

5

COMP

V

REF

GROUND

OUTPUT

RT/C

T

V

CC

I

SENSE

V

FB

COMP

V

REF

GROUND

OUTPUT

1

2

3

4

POWER
GROUND

5

6

7

14

13

12

11

10

9

8

N/C

R

T/CT

I

SENSE

N/C

N/C N/C

V

CC

V

FB

V

C

Oscillator Waveforms and Maximum Duty Cycle

IP1842 SERIES
IP1843 SERIES

Prelim.3/00

Semelab plc. Telephone [phone]. Fax [phone].

E-mail: [e-mail]

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1

2

3

4

8

7

6

5

COMP

V

REF

GROUND

OUTPUT

RT/C

T

V

CC

I

SENSE

V

FB

TYPICAL PERFORMANCE CHARACTERISTICS

COMP

V

REF

GROUND

OUTPUT

1

2

3

4

POWER
GROUND

5

6

7

14

13

12

11

10

9

8

N/C

R

T/CT

I

SENSE

N/C

N/C N/C

V

CC

V

FB

V

C