Datasheet IP1844 Datasheet (SEME LAB)

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

IP1844 SERIES

SEME

IP1845 SERIES

LAB

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

IP1844/IP1845 IP3844
IP2844/IP2845 IP3845

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

REFERENCE SECTION

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

High

OUT

V

Low

OUT

I

= 1mA TJ= 25°C

O

V

= 12V to 25V

CC

I

= 1mA to 20mA

O

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

= 125°C @ 1000Hrs

J

V

= 0

REF

J

= 25°C

4.95 5.00 5.05

4.90 5.10

30 80 160

OSCILLATOR SECTION

= 25°C

T

J

V

= 12V to 25V

CC

∆T

= Min to Max

A

V

Peak to Peak

PIN4

T

= 25°C

J

∆T

= Min to Max

A

47 52 57

ERROR AMP SECTION

V

PIN1

= 2V to 4V

V

O

= 2.5V

2.45 2.50 2.55

65 90

0.7 1

= 12V to 25V

V

CC

V

= 2.7V V

PIN2

V

= 2.3V V

PIN2

V

= 2.3V RL= 15kΩ

PIN2

V

= 2.7V RL= 15kΩ

PIN2

PIN1
PIN1

= 1.1V
= 5.0V

60 70

26

–0.5 –0.8

5.0 6.0

NOTES

1. Test Conditions unless otherwise stated:
V

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

CC

*Adjust V

above start threshold before setting at required level.

CC

620
625

0.2 0.4

50

525

0.2 1
5

1.7

8.3
8

–0.3 –1

0.7 1.1

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

5.0 6.0

0.7 1.1

V

mV

mV

V

µV

mV
mA

kHz

%
%

V

mA

%

V

µA
dB

MHz

dB

mA

V

°C

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

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

Prelim. 2/95

IP1844 SERIES

SEME

IP1845 SERIES

LAB

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

IP1844/IP1845 IP3844
IP2844/IP2845 IP3845

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

CURRENT SENSE SECTION

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

Zener Voltage

CC

Maximum Duty Cycle
Minimum Duty Cycle

See Notes 2,3
V

= 5.0V (Note 2)

PIN1

V

= 12V to 25V

C

2.85 3 3.15

0.9 1 1.1
60 70

OUTPUT SECTION

= 20mA

I

SINK

I

= 200mA

SINK

I

SOURCE

I

SOURCE

C

L

C

L

V

CC

= 20mA

= 200mA
= 1nF
= 1nF

= 6V IL= 1mA

13 13.5
12 13.5

UNDER–VOLTAGE LOCKOUT SECTION

1844 Series
1845 Series
1844 Series
1845 Series

15 16 17

7.8 8.4 9
91011
7 7.6 8.2

TOTAL STANDBY CURRENT

V

= 0V 1844 Series

PIN2

V

= 0V 1845 Series

PIN3

I

CC

= 25mA

30 34 40

PWM SECTION

47 48 50

–2 –10

150 300

0.1 0.4

1.5 2.2

50 150
50 150

0.7 1.1

0.3 0.5
11 15
14 17

0

2.85 3 3.15

0.9 1 1.1
60 70

–2 –10

150 300

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

46 48 50

0

V/V

V
dB
µA

ns

V

V

ns

V

V

V

mA
mA

V

%

NOTES

1. Test Conditions unless otherwise stated:
V

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

CC

*Adjust V
required level.

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

above start threshold before setting at

CC

2. Parameter measured at trip point of latch with
V

= 0V

PIN2

3. Gain defined as:

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

A =
0 ≤ V

∆V
∆V

PIN3

PIN1
PIN3

≤ 0.8

Prelim. 2/95

SEME

LAB

APPLICATIONS INFORMATION

Oscillator Waveforms and Maximum Duty Cycle

LARGE

R

T

C

SMALL

T

IP1844 SERIES
IP1845 SERIES

V - Pin 4
(Pin 7 for 14 Pin D Package)

V

REF

RC

TT

GND

8

R

T

4

C

T

5

Oscillator timing capacitor CTis charged by V
internal current source. During the discharge time, the internal clock signal blanks the
output to the low state. Selection of R
frequency and maximum duty cycle.

Charge and discharge times are determined by the formulae:

SMALL R
LARGE

T

C

T

through RTand discharged by an

REF

and CTtherefore determines both oscillator

T

Internal Clock

Output – Max. Duty Cycle
V - Pin 6
(Pin 10 for 14 Pin D Package)

V - Pin 4
(Pin 7 for 14 Pin D Package)

Internal Clock

Output – Max. Duty Cycle
V - Pin 6
(Pin 10 for 14 Pin D Package)

tc≈ 0.55 RTC

td≈ RTC

T

.0063 R

Rn

T

( )

.0063 – 4

Resultant frequency f =

T

– 2.3

(t

c

For R

Resultant frequency f ≈

1
+ td)

> 5kΩ,

T

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

(R

1.8

TCT

)

Prelim. 2/95

IP1844 SERIES

.01 .0 2 .04 .07 .1 .2 .4 .7 1.0

4

3

2

1

0

60

40

20

0

100

80

10 1k100 10k 10M100k 1M

.05 .5.03 .3

OUTPUT CURRENT, SOURCE / SINK (A) FREQUENCY (Hz)

SATURATION VOLTAGE (V)

VOLTAGE GAIN (dB)

OUTPUT SATURATION CHARACTERISTICS

ERROR AMPLIFIER OPEN-LOOP

FREQUENCY RESPONSE

V = 15V

CC

T = 25˚C

A

A

V

f

SOURCE SAT V - )CCV

OH

SINK SAT (V )

OL

(

A

T = –55˚C

–45

–90

–135

–180

0

PHASE (˚)

0.1

µ

F

1k

Ω

1kW

1k

Ω

ERROR AMP

ADJUST

4.7k

Ω

5k

Ω

ADJUST

4.7k

Ω

100k

Ω

2N2222

I

SENSE

R

T

C

T

0.1

µ

F

V

REF

V

CC

OUTPUT

GROUND

1

2

45

7

8

36

I

SENSE

V

REF

V

CC

O/P

GND

COMP

V

FB

RT/C

T

0

20

15

10

0.5

0

10515200

20

15

10

0.5

0

52.5 7.5 10

UNDER VOLTAGE LOCKOUT

1844 SERIES

UNDER VOLTAGE LOCKOUT

1845 SERIES

V (V)

CC

I (mA)

CC

V (V)

CC

I (m A)

CC

SEME

IP1845 SERIES

LAB

APPLICATIONS INFORMATION

Open–Loop Laboratory Test Fixture

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.

TYPICAL PERFORMANCE CHARACTERISTICS

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

Prelim. 2/95