Seme LAB IP2842A Current mode regulating pulse width modulator Datasheet

IP1842A SERIES
IP1843A SERIES
SEME
LAB
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
Accurate oscillator discharge current
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 IP and UC1842/3 series for
improved operation
• 500kHz Oscillator 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
IP1842A
IP2842A
IP3842A
IP1843A
IP2843A
IP3843A
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.
IP1842AD–14
IP3843AJ
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 @ Tamb > 50°C
Power Dissipation
Derate @ Tcase > 25°C
Storage Temperature Range
Lead Temperature
PD
PD
PD
TSTG
TL
Semelab plc.
(low impedance source)
(ICC < 30mA)
(capacitive load)
(pins 2 and 3)
Tamb = 25°C
J, N Packages
Tcase = 25°C
D Package
Tcase = 25°C
J, N Packages
(soldering, 10 seconds)
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
+30V
Self limiting
±1A
5µJ
–0.3V to +VCC
10mA
1W
10mW/°C
725mW
7.25mW/°C
2W
16mW/°C
–65 to 150°C
+300°C
Prelim. 2/95
IP1842A SERIES
IP1843A SERIES
SEME
LAB
DESCRIPTION
The IP1842A/IP1843A 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 standard IP1842/3 parts these devices offer improved performance in several
areas. They also offer tighter specification and improved performance over the IP and UC1842/3 series, whilst
retaining complete compatibility.
BLOCK DIAGRAM
VCC
7/12
UNDER–VOLTAGE
LOCKOUT
34V
REFERENCE 5V
REGULATOR
ENABLE
G ND
5/9
16V
(8.4V)
6V
(0.5V)
8/14
VREF
INTERNAL
BIAS
REG
2.5V
VREF STATUS
LATCH
S
7/11
R
VC
3.6V
R T /CT
4/7
6/10
OSCILLATOR
Q
T
ERROR
AMP
V FB
2/3
C OMP
1/1
I SENSE
3/5
TOGGLE
FLIP
FLOP *
5/8
OUTPUT
POW ER
GROUND
S
2R
R
R
1V
PWM
LATCH
CURRENT
SENSE
COMPARATOR
* 1844A and 1845A series only.
Values in brackets are for IP1845 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
–0.3V to 3V
(pins 2 and 3)
0 to 2mA
Error Amp Output Sink Current
Operating Ambient Temperature Range
IP1842A , IP1843A
IP2842A , IP2843A
IP3842A , IP3843A
–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 (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 2/95
IP1842A SERIES
IP1843A SERIES
SEME
LAB
ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated)
Test Conditions 1
Parameter
IP1842A , IP1843A
IP2842A , IP2843A
Min.
Typ.
Max.
Min.
IP3842A
IP3843A
Typ.
4.95
4.90
5.00
5.10
Max. Units
REFERENCE SECTION
Output Voltage
IO = 1mA
Input Regulation
Output Regulation
TJ = 25°C
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
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
5
25
30
80
160
47
52
57
1
mV
mV
°C
V
µV
50
50
VREF = 0
5.18
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
∆TA = Min to Max
5
5
%
Amplitude
VPIN4 Peak to Peak
1.7
1.7
V
TJ = 25°C
Discharge Current
7.8
∆TA = Min to Max
8.8
7.8
9
7
2.50
2.55
2.42
–0.3
–1
8.3
7
8.3
8.8
9
mA
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
2.58
V
–0.3
–2
µA
65
90
65
90
dB
0.7
1
0.7
1
MHz
60
70
60
70
dB
2
6
2
6
Output Sink Current
VPIN2 = 2.7V
VPIN1 = 1.1V
Output Source Current
VPIN2 = 2.3V
VPIN1 = 5V
–0.5
–0.8
–0.5
–0.8
VOUT High
VPIN2 = 2.3V
RL = 15kΩ
4.6
6
4.6
6
VOUT Low
VPIN2 = 2.7V
RL = 15kΩ
0.7
1.1
0.7
mA
1.1
V
NOTES
1. Test Conditions unless otherwise stated:
VCC = 15V* , RT = 10kΩ , 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 (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 2/95
IP1842A SERIES
IP1843A SERIES
SEME
LAB
ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated)
Test Conditions 1
Parameter
IP1842A , IP1843A
IP2842A , IP2843A
Min.
Typ.
Max.
Min.
IP3842A
IP3843A
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 = 5V
Supply Voltage
(Note 2)
VC = 12V to 25V
Rejection
dB
Input Bias Current
–2
–10
–2
–10
µA
Delay to Output
150
300
150
300
ns
ISINK = 20mA
0.1
0.4
0.1
0.4
ISINK = 200mA
1.5
2.2
1.5
2.2
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
Rise Time
CL = 1nF
50
150
50
150
Fall Time
CL = 1nF
50
150
50
150
UVLO Saturation
VCC = 6V
0.7
1.1
0.7
1.1
IL = 1mA
V
ns
V
UNDER–VOLTAGE LOCKOUT SECTION
Upper Threshold
IP1842A Series
15
16
17
14.5
16
17.5
(VCC)
IP1843A Series
7.8
8.4
9
7.8
8.4
9
Lower Threshold
IP1842A Series
9
10
11
8.5
10
11.5
(VCC)
IP1843A 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
IP1842A Series
11
15
11
15
Current
VPIN3 = 0V
IP1843A Series
14
17
14
17
VCC Zener Voltage
ICC = 25mA
30
34
40
30
34
40
95
97
100
95
97
100
mA
mA
V
PWM SECTION
Maximum Duty Cycle
Minimum Duty Cycle
0
0
%
NOTES
1. Test Conditions unless otherwise stated:
VCC = 15V* , RT = 10kΩ , 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:
All specifications apply over the full operating temperature
range unless otherwise stated.
(See Ordering Information for further details).
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
∆VPIN1
∆VPIN3
0 ≤ VPIN3 ≤ 0.8
A=
Prelim. 2/95
IP1842A SERIES
IP1843A SERIES
SEME
LAB
APPLICATIONS INFORMATION
Oscillator Waveforms and Maximum Duty Cycle
LARGE R T
SMALL C T
VPIN4 (VPIN7 for 14 pin D package)
INTERNAL CLOCK
V REF
OUTPUT – Max. Duty Cycle
VPIN6 (VPIN10 for 14 pin D package)
8
RT
RTCT
4
LARGE C T
SMALL R T
CT
GND
VPIN4 (VPIN7 for 14 pin D package)
5
INTERNAL CLOCK
OUTPUT – Max. Duty Cycle
VPIN6 (VPIN10 for 14 pin D package)
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 > 5kΩ,
Resultant frequency f ≈
1.8
(RTCT)
Open–Loop Laboratory Test Fixture
VREF
RT
4.7kΩ
VCC
2N2222
100k Ω
1kΩ
ERROR AMP
ADJUST
5kΩ
ISENSE
ADJUST
1 COMP
VREF 8
2 VFB
VCC 7
3 ISENSE
O/P 6
4 R T /C T
GND 5
0.1
µF
0.1
µF
1k Ω
1kW
OUTPUT
4.7kΩ
GROUND
CT
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 (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 2/95
IP1842A SERIES
IP1843A SERIES
SEME
LAB
TYPICAL PERFORMANCE CHARACTERISTICS
ERROR AMPLIFIER OPEN-LOOP
FREQUENCY RESPONSE
OUTPUT SATURATION CHARACTERISTICS
100
TA = –55˚C
2
SOURCE SAT
( VCC- VOH)
1
0
60
–45
(˚)
TA = 25˚C
80
40
f
20
PH ASE
(dB)
VCC = 15V
3
VO LT AG E G AIN
SAT U R AT IO N VO L TAG E (V)
4
–90
–135
AV
0
–180
SINK SAT (VOL )
0
.01
.02
.03 .04 .05
.07
.1
.2
.3
.4
.5
.7
1.0
10
100
OUTPUT CURRENT, SOURCE / SINK (A)
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
1k
10k
100k
1M
10M
FREQUENCY (Hz)
Prelim. 2/95
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