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
μ
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
μ
F
0 to 500
–55 to +125°C
0 to +70°C
RECOMMENDED OPERATING CONDITIONS
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
BLOCK DIAGRAM
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”.