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Электронный компонент: IP3843

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IP1842 SERIES
IP1843 SERIES
Prelim.3/00
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail:
sales@semelab.co.uk
Website:
http://www.semelab.co.uk
CURRENT MODE
REGULATING
PULSE WIDTH
MODULATORS
FEATURES
Guaranteed 1% reference voltage tolerance
Guaranteed 10% frequency tolerance
Low startup current (<500
mmm
m
A)
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)
(I
CC
< 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
= 25C
Derate @ T
amb
> 50C
P
D
Power Dissipation
T
case
= 25C
Derate @ T
case
> 25C
T
STG
Storage Temperature Range
T
L
Lead Temperature
(soldering, 10 seconds)
+30V
Self limiting
1A
5
m
J
0.3V to +V
CC
10mA
1W
10mW/C
2W
24mW/C
65 to 150C
+300C
ABSOLUTE MAXIMUM RATINGS
(T
case
= 25C 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
R
T
/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
/C
T
I
SENSE
N/C
N/C
N/C
V
CC
V
FB
V
C
Part JPack
NPack
D8
D14
Temp.
Number
8 Pin
8 Pin
8 Pin
14 Pin
Range
IP1842
-55 to +125C
IP2842
-25 to +85C
IP3842
0 to +70C
IP1843
-55 to +125C
IP2843
-25 to +85C
IP3843
0 to +70C
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 +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail:
sales@semelab.co.uk
Website:
http://www.semelab.co.uk
DESCRIPTION
The IP1842 and IP1843 series of switching regulator control circuits contain all the functions necessary to
implement offline, 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.
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
PW M
LATCH
CURRENT
SENSE
COM PARATOR
16V
(8.4V)
6V
(0.5V)
2.5V
UNDERVOLTAGE
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
/C
R
T
T
POW ER
GROUND
V
C
PIN NUM BERS
1st Num ber
2nd Num ber
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 125C
25 to 85C
0 to 70C
Notes:
1.
Lower limit set by under voltage lockout specification.
RECOMMENDED OPERATING CONDITIONS
NOTES
1. Test Conditions unless otherwise stated:
V
CC
= 15V* , R
T
= 10k
W
, C
T
= 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
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail:
sales@semelab.co.uk
Website:
http://www.semelab.co.uk
4.90
5.00
5.10
6
20
6
25
0.2
0.4
4.82
5.18
50
5
25
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
2
6
0.5
0.8
4.6
4.8
0.7
1.1
4.95
5.00
5.05
6
20
6
25
0.2
0.4
4.90
5.10
50
5
25
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
2
6
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
T
J
= 25C
V
CC
= 12V to 25V
I
O
= 1mA to 20mA
Line, Load, Temp
f = 10Hz to 10kHz
T
J
= 25C
T
J
= 125C @ 1000Hrs
V
REF
= 0
T
J
= 25C
V
CC
= 12V to 25V
D
T
A
= Min to Max
V
PIN4
Peak to Peak
T
J
= 25C
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
R
L
= 15k
W
V
PIN2
= 2.7V
R
L
= 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
0.9
1
1.1
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
0.9
1
1.1
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
9
10
11
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
)
Startup 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
T
J
= 25C
C
L
= 1nF
T
J
= 25C
V
CC
= 6V
I
L
= 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* , R
T
= 10k
W
, C
T
= 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 +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail:
sales@semelab.co.uk
Website:
http://www.semelab.co.uk
ELECTRICAL CHARACTERISTICS
(Over Full Operating Temperature Range unless otherwise stated)
CURRENT SENSE SECTION
OUTPUT SECTION
UNDERVOLTAGE LOCKOUT SECTION
TOTAL STANDBY CURRENT
t
c
0.55 R
T
C
T
t
d
R
T
C
T
R
n
1
Resultant frequency f =
(t
c
+ t
d
)
For R
T
> 5k
W
,
1.8
Resultant frequency f
(R
T
C
T
)
Oscillator timing capacitor C
T
is charged by V
REF
through R
T
and 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 R
T
2.3
.0063 4
( )
IP1842 SERIES
IP1843 SERIES
Prelim.3/00
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail:
sales@semelab.co.uk
Website:
http://www.semelab.co.uk
OpenLoop 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
R
T
/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
/C
T
I
SENSE
N/C
N/C
N/C
V
CC
V
FB
V
C
Oscillator Waveforms and Maximum Duty Cycle