Seme LAB IP3842 Current mode regulating pulse width modulator Datasheet

IP1842 SERIES
IP1843 SERIES
TOP VIEW
COMP 1
8
VREF
V FB 2
7
VCC
I SENSE 3
6
OUTPUT
R T /C T 4
5
GROUND
CURRENT MODE
REGULATING
PULSE WIDTH
MODULATORS
J Package – 8 Pin Ceramic DIP
N Package – 8 Pin Plastic DIP
D-8 Package – 8 Pin Plastic (150) SOIC
FEATURES
•
•
•
•
•
Guaranteed ±1% reference voltage tolerance
Guaranteed ±10% frequency tolerance
Low start–up current (<500 mA)
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
TOP VIEW
COMP 1
14
VREF
N/C
2
13
N/C
V FB 3
12
VCC
N/C
4
11
VC
I SENSE 5
10
OUTPUT
6
9
GROUND
R T /C T 7
8
POWER
GROUND
N/C
D-14 Package – 14 Pin Plastic (150) SOIC
Order Information
Part
Number
IP1842
IP2842
IP3842
IP1843
IP2843
IP3843
J–Pack
8 Pin
✔
✔
✔
✔
✔
✔
N–Pack
8 Pin
✔
✔
✔
✔
D–8
8 Pin
✔
✔
✔
✔
D–14
14 Pin
✔
✔
✔
✔
Temp.
Range
-55 to +125°C
-25 to +85°C
0 to +70°C
-55 to +125°C
-25 to +85°C
0 to +70°C
Note:
To order, add the package identifier to the
part number.
eg.
IP1842J
IP3843D-14
ABSOLUTE MAXIMUM RATINGS (Tcase = 25°C unless otherwise stated)
VCC
Supply Voltage
IO
Output Current
Output Energy
Analog Inputs
Error Amp Output Sink Current
Power Dissipation
Derate @ Tamb > 50°C
Power Dissipation
Derate @ Tcase > 25°C
Storage Temperature Range
Lead Temperature
PD
PD
TSTG
TL
Semelab plc.
(low impedance source)
(ICC < 30mA)
(capacitive load)
(pins 2 and 3)
Tamb = 25°C
Tcase = 25°C
(soldering, 10 seconds)
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail: [email protected]
Website: http://www.semelab.co.uk
+30V
Self limiting
±1A
5mJ
–0.3V to +VCC
10mA
1W
10mW/°C
2W
24mW/°C
–65 to 150°C
+300°C
Prelim.3/00
IP1842 SERIES
IP1843 SERIES
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 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
VCC
7/12
UNDER–VOLTAGE
LOCKOUT
34V
ENABLE
G ND
REFERENCE 5V
REGULATOR
5/9
16V
(8.4V)
6V
(0.5V)
8/14
VREF
INTERNAL
BIAS
REG
2.5V
S
VREF STATUS
LATCH
7/11
R
VC
3.6V
R T /CT
6/10
4/7
OSCILLATOR
ERROR
AMP
V FB
2/3
C OMP
1/1
I SENSE
3/5
S
2R
R
R
1V
5/8
PWM
LATCH
OUTPUT
POW ER
GROUND
CURRENT
SENSE
COMPARATOR
Values in brackets are for IP1843 series.
PIN NUMBERS
1st Number – N, J and 8 Pin D Packages
2nd Num ber – 14 Pin D Package.
RECOMMENDED OPERATING CONDITIONS
VCC
Supply Voltage 1
IO
Output Current
Analog Inputs
£
30V
0 to ±200mA
(pins 2 and 3)
–0.3V to 3V
Error Amp Output Sink Current
Operating Ambient Temperature Range
0 to 2mA
IP1842 , IP1843
IP2842 , IP2843
IP3842 , IP3843
–55 to 125°C
–25 to 85°C
0 to 70°C
Notes:
1.
Lower limit set by under voltage lockout specification.
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail: [email protected]
Website: http://www.semelab.co.uk
Prelim.3/00
IP1842 SERIES
IP1843 SERIES
ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated)
Parameter
Test Conditions
IP1842/IP1843
IP2842/IP2843
Min.
Typ.
Max.
Min.
IP3842
IP3843
Typ.
4.95
4.90
5.00
5.10
Max. Units
REFERENCE SECTION
5.00
5.05
VCC = 12V to 25V
6
20
6
20
IO = 1mA to 20mA
6
25
6
25
0.2
0.4
0.2
0.4
Output Voltage
IO = 1mA
Input Regulation
Output Regulation
TJ = 25°C
Temperature Stability
Total Output Variation
Line, Load, Temp
Output Noise Voltage
f = 10Hz to 10kHz
Long Term Stability
TJ = 125°C @ 1000Hrs
Output Short Circuit
Current
4.90
TJ = 25°C
5.10
4.82
50
50
VREF = 0
5.18
5
25
30
80
160
47
52
57
1
V
mV
mV
°C
V
m
V
5
25
mV
30
80
160
mA
47
52
57
kHz
0.2
1
%
OSCILLATOR SECTION
Frequency
TJ = 25°C
Voltage stability
VCC = 12V to 25V
0.2
Temperature Stability
D
TA = Min to Max
5
5
%
Amplitude
VPIN4 Peak to Peak
1.7
1.7
V
TJ = 25°C
8.3
8.3
mA
8
8
%
Discharge Current
TA = Min to Max
D
ERROR AMP SECTION
Input Voltage
VPIN1 = 2.5V
2.45
Input Bias Current
Open Loop Voltage
Gain
VO = 2V to 4V
Unity Gain Bandwidth
Supply Voltage
VCC = 12V to 25V
Rejection
2.50
2.55
–0.3
–1
2.42
2.50
2.58
–0.3
–2
V
m
A
65
90
65
90
dB
0.7
1
0.7
1
MHz
60
70
60
70
dB
Output Sink Current
VPIN2 = 2.7V
VPIN1 = 1.1V
2
6
2
6
Output Source Current
VPIN2 = 2.3V
VPIN1 = 4.6V
–0.5
–0.8
–0.5
–0.8
VOUT High
VPIN2 = 2.3V
RL = 15kW
4.6
4.8
4.6
4.8
VOUT Low
VPIN2 = 2.7V
RL = 15kW
0.7
1.1
0.7
mA
1.1
V
NOTES
1. Test Conditions unless otherwise stated:
VCC = 15V* , RT = 10kW , CT = 3.3nF , f = 52kHz.
*Adjust VCC 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).
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail: [email protected]
Website: http://www.semelab.co.uk
Prelim.3/00
IP1842 SERIES
IP1843 SERIES
ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated)
Parameter
Test Conditions
IP1842/IP1843
IP2842/IP2843
Min.
Typ.
Max.
Min.
IP3842
IP3843
Typ.
2.85
3
3.15
2.85
3
3.15
V/V
0.9
1
1.1
0.9
1
1.1
V
60
70
60
70
Max. Units
CURRENT SENSE SECTION
Gain
See Notes 2,3
Maximum Input Signal
VPIN1 = 4.6V
Supply Voltage
(Note 2)
VC = 12V to 25V
Rejection
dB
Input Bias Current
–2
–10
–2
–10
m
Delay to Output
200
400
200
400
ns
ISINK = 20mA
0.1
0.4
0.1
0.4
ISINK = 200mA
1.5
2.2
1.5
2.2
A
OUTPUT SECTION
Output Low Level
Output High Level
ISOURCE = 20mA
13
13.5
13
13.5
ISOURCE = 200mA
12
13.5
12
13.5
V
V
Rise Time
CL = 1nF
TJ = 25°C
50
150
50
150
Fall Time
CL = 1nF
TJ = 25°C
50
150
50
150
UVLO Saturation
VCC = 6V
IL = 1mA
0.7
1.1
0.7
1.1
ns
V
UNDER–VOLTAGE LOCKOUT SECTION
Upper Threshold
1842 Series
15
16
17
14.5
16
17.5
(VCC)
1843 Series
7.8
8.4
9
7.8
8.4
9
Lower Threshold
1842 Series
9
10
11
8.5
10
11.5
(VCC)
1843 Series
7
7.6
8.2
7
7.6
8.2
0.3
0.5
0.3
0.5
V
V
TOTAL STANDBY CURRENT
Start–up Current
Operating Supply
VPIN2 = 0V
1842 Series
11
15
11
15
Current
VPIN3 = 0V
1843 Series
14
17
14
17
VCC Zener Voltage
ICC = 25mA
34
40
34
40
30
30
mA
mA
V
NOTES
1. Test Conditions unless otherwise stated:
VCC = 15V* , RT = 10kW , CT = 3.3nF , f = 52kHz.
*Adjust VCC above start threshold before setting at
required level.
2. Parameter measured at trip point of latch with
VPIN2 = 0V
3. Gain defined as:
A=
VPIN1
VPIN3
D
D
All specifications apply over the full operating temperature
range unless otherwise stated.
(See Ordering Information for further details).
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail: [email protected]
Website: http://www.semelab.co.uk
0 £ VPIN3 £ 0.8
Prelim.3/00
IP1842 SERIES
IP1843 SERIES
APPLICATIONS INFORMATION
Oscillator Waveforms and Maximum Duty Cycle
COMP 1
8
VREF
V FB 2
7
VCC
I SENSE 3
6
OUTPUT
R T /C T 4
5
GROUND
Oscillator timing capacitor C T is charged by V REF tc » 0.55 RTCT
through RT and discharged by an internal current source.
.0063 RT – 2.3
During the discharge time, the internal clock signal td » RTCT Rn
.0063 – 4
blanks the output to the low state. Selection of RT and
1
CT therefore determines both oscillator frequency and Resultant frequency f =
(tc + td)
maximum duty cycle. Charge and discharge times are
determined by the formulae:
(
)
For RT > 5kW,
Resultant frequency f »
1.8
(RTCT)
Open–Loop Laboratory Test Fixture
COMP 1
14
VREF
N/C
2
13
N/C
V FB 3
12
VCC
N/C
4
11
VC
I SENSE 5
10
OUTPUT
6
9
GROUND
R T /C T 7
8
POWER
GROUND
N/C
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.
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail: [email protected]
Website: http://www.semelab.co.uk
Prelim.3/00
IP1842 SERIES
IP1843 SERIES
TYPICAL PERFORMANCE CHARACTERISTICS
COMP 1
8
VREF
V FB 2
7
VCC
I SENSE 3
6
OUTPUT
R T /C T 4
5
GROUND
COMP 1
14
VREF
N/C
2
13
N/C
V FB 3
12
VCC
N/C
4
11
VC
I SENSE 5
10
OUTPUT
6
9
GROUND
R T /C T 7
8
POWER
GROUND
N/C
Semelab plc.
Telephone +44(0)1455 556565. Fax +44(0)1455 552612.
E-mail: [email protected]
Website: http://www.semelab.co.uk
Prelim.3/00
Similar pages