LAB
SEME
IP1525A SERIES
IP1527A SERIES
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 3/95
REGULATING
PULSE WIDTH
MODULATORS
FEATURES
8 to 35V operation
5.1V reference trimmed to 1%
100Hz to 500kHz oscillator range
Separate oscillator sync terminal
Adjustable deadtime control
Internal soft start
Input undervoltage lockout
Latching PWM to prevent multiple pulses
Dual source/sink output drivers
+V
IN
Input Voltage
Collector Voltage
Logic Inputs
Analogue Inputs
Output Current, Source or Sink
Reference Output Load Current
Oscillator Charging Current
P
D
Power Dissipation
T
A
= 25C
Derate @ T
A
> 50C
P
D
Power Dissipation
T
C
= 25C
Derate @ T
C
> 25C
T
J
Operating Junction Temperature
T
STG
Storage Temperature Range
T
L
Lead Temperature
(soldering, 10 seconds)
+40V
+40V
0.3 to +5.5V
0.3 to +V
IN
500mA
Internally Limited
5mA
1W
10mW/C
2W
16mW/C
See Ordering Information
65 to +150C
+300C
ABSOLUTE MAXIMUM RATINGS
(T
case
= 25C unless otherwise stated)
TOP VIEW
J Package 16 Pin Ceramic DIP
N Package 16 Pin Plastic DIP
D Package 16 Pin Plastic (300) SOIC
8
1
2
3
4
5
6
7
14
13
12
11
10
9
15
16
INV. INPUT
N. I. INPUT
OSC. OUTPUT
SOFT START
DISCHARGE
SYNC
V
REF
V
IN
OUTPUT B
GROUND
SHUTDOWN
COMPENSATION
C
V
OUTPUT A
C
T
R
T
Part JPack
NPack
D16
Temp.
Number
16 Pin
16 Pin
16 Pin
Range
IP1525A
-55 to +125C
IP1527A
-55 to +125C
IP3525A
0 to +70C
IP3527A
0 to +70C
Order Information
Note:
To order, add the package identifier to the part number.
eg.
IP1525AJ
IP3527AD16
LAB
SEME
IP1525A SERIES
IP1527A SERIES
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 3/95
Q
Q
PWM
INV.
INPUT
N.I.
INPUT
1
2
ERROR
AMP
T
T
OSCILLATOR
R
C
OSC. OUTPUT
6
5
TO INTERNAL
CIRCUITRY
V
REF
16
15
12
REFERENCE
REGULATOR
GND
+V
IN
3
SYNC
4
DISCHARGE
+V
IN
COMPENSATION
SOFT START
8
V
REF
50
A
SHUTDOWN
10
5k
U.V.
LOCKOUT
FLIP
FLOP
S
R
LATCH
OUTPUT A
V
C
11
14
13
OUTPUT B
5k
9
7
IP1525A OUTPUT STAGE
OUTPUT A
V
C
11
14
13
OUTPUT B
IP1527A OUTPUT STAGE
+8 to +35V
+4.5 to +35V
0 to 100mA
0 to 400mA
0 to 20mA
100Hz to 400kHz
2k
to 200k
470pF to 0.1
F
0 to 500
55 to +125C
0 to +70C
RECOMMENDED OPERATING CONDITIONS
BLOCK DIAGRAM
V
IN
Input Voltage
Collector Voltage
Sink/Source Load Current (Steady State)
Sink/Source Load Current (Peak)
Reference Load Current
Oscillator Frequency Range
R
T
Oscillator Timing Resistor
C
T
Oscillator Timing Capacitor
Deadtime Resistor Range
Operating Ambient Temperature Range
IP1525A / IP1527A
IP3525A / IP3527A
DESCRIPTION
The IP1525A and IP1527A families of PWM switching regulator control circuits offer improved performance and lower
parts count when used in designing switching power supplies. Included are 5.1 volt reference, error amplifier, adjustable
dead-time oscillator with synchronisation capability, latched PWM comparator, totem-pole output drivers, shutdown, soft
start, and undervoltage lockout.
The IP1525A and IP1527A differ only in output phasing. The IP1525A output is low when "off", while the IP1527A
output is high when "off".
Output Voltage
Line Regulation
Load Regulation
Temperature Stability
Total Output Variation
Short Circuit Current
Output Noise Voltage
Long Term Stability
Initial Accuracy
Voltage Stability
Temperature Stability
Minimum Frequency
Maximum Frequency
Current Mirror
Clock Amplitude
Clock Width
Sync Threshold
Sync Input Current
Input Offset Voltage
Input Bias Current
Input Offset Current
DC Open Loop Gain
Gain Bandwidth Product
T
J
= 25C
V
IN
= 8 to 35V
I
L
= 0 to 20mA
Over Line, Load and Temp.
V
REF
= 0
f = 10 Hz to 10kHz
V
IN
= 8 to 35V
R
T
= 200k
C
T
= 0.1
F
R
T
= 2k
C
T
= 470pF
I
RT
= 2mA
T
J
= 25C
Sync Voltage = 3.5V
R
L
10M
T
J
= 25C
LAB
SEME
IP1525A SERIES
IP1527A SERIES
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 3/95
IP1525A
IP3525A
IP1527A
IP3527A
Parameter
Test Conditions
Min.
Typ.
Max.
Min.
Typ.
Max.
Units
ELECTRICAL CHARACTERISTICS
(T
J
= Over Operating Temperature Range unless otherwise stated)
5.0
5.1
5.2
2
20
5
50
20
50
4.95
5.25
80
100
40
200
1
50
2
6
1
2
3
6
90
120
400
600
1.7
2.0
2.2
3.0
3.5
0.3
0.5
1.0
1.2
2.0
2.8
1.0
2.5
2
10
1
10
1
60
75
1
2
5.05
5.10
5.15
2
10
5
50
20
50
5.0
5.2
80
100
40
200
1
10
2
6
0.3
1
3
6
90
120
400
600
1.7
2.0
2.2
3.0
3.5
0.3
0.5
1.0
1.2
2.0
2.8
1.0
2.5
0.5
5
1
10
1
60
75
1
2
V
mV
mV
V
mA
Vrms
mV
kHr
%
Hz
kHz
mA
V
s
V
mA
mV
A
dB
MHz
REFERENCE SECTION
OSCILLATOR SECTION
2
ERROR AMPLIFIER SECTION
3
NOTES
1. Test Conditions unless otherwise stated:
V
IN
= 20V
T
J
= 55 to +125C for IP1525A / IP1527A
T
J
= 0 to +70C
for IP3525A / IP3527A
2. Oscillator Section Test Conditions:
f
OSC
= 40kHz
(R
T
= 3.6k
, C
T
= 0.01
F , R
D
= 0)
3. Error Amplifier Section Test Condition:
V
CM
= 5.1V
4. Output Driver Section Test Condition:
V
C
= 20V
V
CM
= 1.5 to 5.2V
V
IN
= 8 to 35V
V
PIN1
V
PIN2
150mV
V
PIN2
V
PIN1
150mV
Zero Duty Cycle
Max. Duty Cycle
V
SHUTDOWN
= 0V
V
SHUTDOWN
= 2V
To Outputs
V
SHUTDOWN
= 2.5V
V
SHUTDOWN
= 2.5V
T
J
= 25C
I
SINK
= 20mA
I
SINK
= 100mA
I
SOURCE
= 20mA
I
SOURCE
= 100mA
V
COMP
= High
V
C
= 35V
C
L
= 1nF
T
J
= 25C
C
L
= 1nF
T
J
= 25C
V
IN
= 35V
Output Low Level
Output High Level
Common Mode Rejection
Supply Voltage Rejection
Minimum Duty Cycle
Maximum Duty Cycle
Input Threshold
Input Threshold
Input Bias Current
Soft Start Current
Soft Start Low Level
Shutdown Threshold
Shutdown Input Current
Shutdown Delay
Output Low Level
Output High Level
Undervoltage Lockout
Output Leakage
Rise Time
Fall Time
Supply Current
IP1525A
IP3525A
IP1527A
IP3527A
Parameter
Test Conditions
Min.
Typ.
Max.
Min.
Typ.
Max.
Units
0.2
0.5
3.8
5.6
60
75
50
60
0
45
49
0.6
0.9
3.3
3.6
0.05
1.0
25
50
80
0.4
0.6
0.6
1.3
2.0
0.1
1.0
0.2
0.5
0.2
0.4
1.0
2.0
18
19
17
18
5
7
8
200
100
600
50
300
10
20
0.2
0.5
3.8
5.6
60
75
50
60
0
45
49
0.6
0.9
3.3
3.6
0.05
1.0
25
50
80
0.4
0.6
0.6
1.3
2.0
0.1
1.0
0.2
0.5
0.2
0.4
1.0
2.0
18
19
17
18
5
7
8
200
100
600
50
300
10
20
V
dB
%
V
A
A
V
mA
s
V
V
V
A
ns
mA
LAB
SEME
IP1525A SERIES
IP1527A SERIES
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 3/95
NOTES
1. Test Conditions unless otherwise stated:
V
IN
= 20V
T
J
= 55 to +125C for IP1525A / IP1527A
T
J
= 0 to +70C
for IP3525A / IP3527A
2. Oscillator Section Test Conditions:
f
OSC
= 40kHz
(R
T
= 3.6k
, C
T
= 0.01
F , R
D
= 0)
3. Error Amplifier Section Test Condition:
V
CM
= 5.1V
4. Output Driver Section Test Condition:
V
C
= 20V
ELECTRICAL CHARACTERISTICS
(T
J
= Over Operating Temperature Range unless otherwise stated)
PWM COMPARATOR
ERROR AMPLIFIER SECTION (cont.)
3
SHUTDOWN SECTION
OUTPUT DRIVERS (each output)
4
TOTAL STANDBY CURRENT
1 3
A
B
IP1 5 2 5 A
+ V
C
G N D
1 2
1 1
1 4
+ V
S U P P L Y
R 1
R E T U R N
T 1
Q 1
Q 2
LAB
SEME
IP1525A SERIES
IP1527A SERIES
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 3/95
APPLICATIONS INFORMATION
TO OU TPU T FIL TER
1 3
R 2
A
B
IP 1 52 5A
+ V
C
G N D
1 2
R 1
1 1
1 4
+ V
S U P PL Y
R E TU R N
Q 1
1 3
A
B
I P1 5 2 5A
+ V
C
G N D
1 2
1 1
1 4
+ V
S U P P L Y
R 1
R E TU R N
R 2
C 2
R 3
C 1
Q 1
Q 2
T 1
1 3
A
B
IP 1 52 5A
+ V
C
G N D
1 2
+ V
S U P PL Y
Q 1
T 1
T2
Q 2
1 1
1 4
R 1
R 2
R E T U R N
C 1
C 2
For singleended supplies, the driver outputs are grounded.
The V
C
terminal is switched to ground by the totempole
source transistors on alternate oscillator cycle.
In conventional pushpull bipolar designs, forward base drive
is controlled by R1R3. Rapid turnoff times for the power
devices are achieved with speedup capacitors C1 and C2.
Low power transfor mers can be driven directly by the
IP1525A. Automatic reset occurs during deadtime when both
ends of the primary winding are switched to ground.
The low source impedance of the output drivers provides
rapid charging of power FET input capacitance while minimis-
ing external components.
LAB
SEME
IP1525A SERIES
IP1527A SERIES
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 3/95
CHARGE TIME (
s)
10
100
200
1
1
ms
10
ms
1
2
5
20
50
10
200
500
100
2
ms
5
ms
2
5
20
50
R
T
I
MIN
G
RE
S
I
S
T
O
R
(
k
)
T
C
=
1
n
F
T
C
=
2
n
F
T
C
=
5
n
F
T
C
=
0
.0
1
F
T
C
=
0
.0
2
F
T
C
=
0
.0
5
F
T
C
=
0
.1
F
T
7
5
R
T
R
D
C
T
6
DISCHARGE TIME (
s)
100
200
300
400
500
0
R DE
A
D
T
I
M
E
RE
S
I
S
T
O
R
(
)
D
C
=
1n
F
T
C
=
2n
F
T
C
=
5n
F
T
C
=
0
.
01
F
T
C
=
0
.
02
F
T
C
=
0
.
05
F
T
C
=
0
.
1
F
T
0.2
1
10
100
200
0.5
5
2
20
50
TYPICAL PERFORMANCE CHARACTERISTICS
Oscillator Charge Time vs
R
T
and C
T
Oscillator Discharge Time vs.
R
D
and C
T
FREQUENCY (Hz)
C
=
1n
F
P
C
=
0
P
-20
0
20
40
60
80
100
1
10
100
1k
10k
100k
1M
10M
R = 20k
Z
R
=
0
Z
V
O
L
T
A
G
E
G
A
IN
(
d
B
)
C
P
R
Z
9
1
2
1
2
3
4
OUTPUT CURRENT, SOURCE or SINK (A)
0
0.01
1
0.1
0.2
0.3
0.5
0.7
0.02
0.03
0.05 0.07
SA
T
U
R
A
T
I
O
N
VO
L
T
A
G
E (
V
)
V = 20V
IN
T = 25C
A
SOURCE SAT, V - V
OH
C
SINK SAT, V
OL
Error Amplifier OpenLoop
Frequency Response
IP1525A Output Saturation
Characteristics
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