Document Outline
- Main Menu
- Analog & Mixed Signal
- Regulators PSG
- Regulators Index
- Search
- fairchildsemi.com
KA3525A SMPS CONTROLLER
VOLTAGE-MODE PWM CONTROLLER
The KA3525A is a monolithic integrated circuit that Included all of
the control circuit necessary for a pulse width modulating regulator.
There are a voltage reference, an error amplifier, a pulse width
modulator, an oscillator, under-voltage lockout, soft start circuit, and
output drivers in the chip.
FEATURES
5V
1% Reference
Oscillator Sync Terminal
Internal Soft Start
Deadtime Control
Under-Voltage Lockout
ORDERING INFORMATION
BLOCK DIAGRAM
5.5K
5.5K
43K
Device
Package
Operating Temperature
KA3525A
16 DIP
-30 ~ +85
KA3525AD
16-SOP-225A
-30 ~ +85
16-DIP
16-SOP-225A
1999 Fairchild Semiconductor Corporation
Rev. B
KA3525A SMPS CONTROLLER
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
CC
= 20V, T
A
= -35
to + 85
, unless otherwise specified)
Characteristic
Symbol
Value
Unit
Supply Voltage
V
CC
40
V
Collector Supply Voltage
V
C
40
V
Output Current, Sink or Source
I
O
500
mA
Reference Output Current
I
REF
50
mA
Oscillator Charging Current
I
CHG(OSC)
5
mA
Power Dissipation (T
A
= 25
)
P
D
1000
m/W
Operating Temperature
T
OPR
0 ~ +70
Storage Temperature
T
STG
-65 ~ +150
Lead Temperature (Soldering, 10 sec)
T
LEAD
+300
Characteristic
Symbol
Test Conditions
Min
Typ
Max
Unit
REFERENCE SECTION
Reference Output Voltage
V
REF
T
J
= 25
5.0
5.1
5.2
V
Line Regulation
L
V
REF
V
CC
= 8 to 35V
9
20
mV
Load Regulation
L
V
REF
I
REF
= 0 to 20mA
20
50
mV
Short Circuit Output Current
I
SC
V
REF
= 0, T
J
= 25
80
100
mA
Total Output Variation (Note 1)
L
V
REF
Line, Load and Temperature
4.95
5.25
V
Temperature Stability (Note 1)
ST
T
20
50
mV
Long Term Stability (Note 1)
ST
T
J
= 125
, 1 KH
RS
20
50
mV
OSCILLATOR SECTION
Initial Accuracy (Note 1, 2)
ACCUR
T
J
= 25
3
6
%
Frequency Change With Voltage
L
f/
L
V
CC
V
CC
= 8 to 35V (Note 1, 2)
0.8
2
%
Maximum Frequency
f
(MAX)
R
T
= 2K
`
, C
T
= 470pF
400
430
KHz
Minimum Frequency
f
(MIN)
R
T
= 200K
`
, C
T
= 0.1
s
F
60
120
Hz
Clock Amplitude (Note 1, 2)
V
(CLK)
3
4
V
Clock Width (Note 1, 2)
t
W(CLK)
T
J
= 25
0.3
0.6
1
s
s
Sync Threshold
V
TH(SYNC)
1.2
2
2.8
V
Sync Input Current
I
I(SYNC)
Sync = 3.5V
1.3
2.5
mA
KA3525A SMPS CONTROLLER
ELECTRICAL CHARACTERISTICS
(V
CC
= 20V, T
A
= -35
to +85
, unless otherwise specified)
(Note)
1. These parameters. although guaranteed over the recommended operating conditions, are not 100% tested in
production
2.
Tested at f
OSC
=40 KHz (R
T
=3.6K, C
T
=0.01
s
F, R
I
= 0
`
)
Characteristic
Symbol
Test Conditions
Min
Typ
Max
Unit
ERROR AMPLIFIER SECTION (V
CM
= 5.1V)
Input Offset Voltage
V
IO
1.5
10
mV
Input Bias Current
I
BAIS
1
10
s
A
Input Offset Current
I
IO
0.1
1
s
A
Open Loop Voltage Gain
G
VO
R
L
10M
`
60
80
dB
Common Mode Rejection Ratio
CMRR
V
CM
= 1.5 to 5.2V
60
90
dB
Power Supply Rejection Ratio
PSRR
V
CC
= 8 to 3.5V
50
60
dB
PWM COMPARATOR SECTION
Minimum Duty Cycle
D
(MIN)
0
%
Maximum Duty Cycle
D
(MAX)
45
49
%
Input Threshold Voltage (Note 2)
V
TH1
Zero Duty Cycle
0.7
0.9
V
Input Threshold Voltage (N0te 2)
V
TH2
Max Duty Cycle
3.2
3.6
V
SOFT-START SECTION
Soft Start Current
I
SOFT
V
SD
= 0V, V
SS
= 0V
25
51
80
s
A
Soft Start Low Level Voltage
V
SL
V
SD
= 25V
0.3
0.7
V
Shutdown Threshold Voltage
V
TH(SD)
0.7
1.3
1.7
V
Shutdown Input Current
I
N(SD)
V
SD
= 2.5V
0.3
1
mA
OUTPUT SECTION
Low Output Voltage I
V
OL I
I
SINK
= 20mA
0.1
0.4
V
Low Output Voltage II
V
OL II
I
SINK
= 100mA
0.05
2
V
High Output Voltage I
V
CH I
I
SOURCE
= 20mA
18
19
V
High Output Voltage II
V
CH II
I
SOURCE
= 100mA
17
18
V
Under Voltage Lockout
V
UV
V
8
and V
9
= High
6
7
8
V
Collector Leakage Current
I
LKG
V
CC
= 35V
80
200
s
A
Rise Time (Note 1)
t
R
C
L
= 1
s
F, T
J
= 26
80
600
nS
Fall Time (Note 1)
t
F
C
L
= 1
s
F, T
J
= 25
70
300
nS
STANDBY CURRENT
Supply Cuttent
I
CC
V
CC
= 35V
12
20
mA
KA3525A SMPS CONTROLLER
TEST CIRCUIT
TRADEMARKS
ACExTM
CoolFETTM
CROSSVOLTTM
E
2
CMOS
TM
FACTTM
FACT Quiet SeriesTM
FAST
FASTrTM
GTOTM
HiSeCTM
The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is
not intended to be an exhaustive list of all such trademarks.
LIFE SUPPORT POLICY
FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
As used herein:
ISOPLANARTM
MICROWIRETM
POPTM
PowerTrenchTM
QSTM
Quiet SeriesTM
SuperSOTTM-3
SuperSOTTM-6
SuperSOTTM-8
TinyLogicTM
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant into
the body, or (b) support or sustain life, or (c) whose
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
reasonably expected to result in significant injury to the
user.
2. A critical component is any component of a life
support device or system whose failure to perform can
be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or
effectiveness.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification
Product Status
Definition
Advance Information
Preliminary
No Identification Needed
Obsolete
This datasheet contains the design specifications for
product development. Specifications may change in
any manner without notice.
This datasheet contains preliminary data, and
supplementary data will be published at a later date.
Fairchild Semiconductor reserves the right to make
changes at any time without notice in order to improve
design.
This datasheet contains final specifications. Fairchild
Semiconductor reserves the right to make changes at
any time without notice in order to improve design.
This datasheet contains specifications on a product
that has been discontinued by Fairchild semiconductor.
The datasheet is printed for reference information only.
Formative or
In Design
First Production
Full Production
Not In Production
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER
NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD
DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT
OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT
RIGHTS, NOR THE RIGHTS OF OTHERS.
UHCTM
VCXTM
PDF 
ZIP