UNISONIC TECHNOLOGIES CO., LTD
3521
PWM CONTROLLER WITH
SUPERVISORY CIRCUIT FOR
SWITCHING POWER SUPPLY
DESCRIPTION
UTC
3521
PWM controller is designed for switching mode power
supply for PCs. It provides all the functions necessary to monitor and
control the output of the power supply. Remote ON/OFF control,
power good circuitry, some protection features against over-voltage
and over-power are implements.
CMOS IC
DIP-16
FEATURES
* Over-Voltage Protection for 3.3V, 5V and 12V
* Under-Voltage Detection for 3.3V, 5V and 12V
* Over-Power Protection
* Remote ON/OFF Function
* Power Good Circuitry
* Delay Time for PG Signal
* Delay Time for Over-Voltage and Under-Voltage Protection
* On-Chip Oscillator and Error Amplifier
ORDERING INFORMATION
Ordering Number
Lead Free Plating
Halogen Free
3521L-D16-T
3521G-D16-T
Package
DIP-16
Packing
Tube
3521L-D16-T
(1)Packing Type
(2)Package Type
(3)Lead Free
(1) T: Tube
(2) D16: DIP-16
(3) L: Lead Free, G: Halogen Free
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Copyright © 2010 Unisonic Technologies Co., Ltd
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PIN CONFIGURATION
V33
V5
V12
PT
GND
CT
C1
C2
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
ADJ
OPNEGIN
OPOUT
V
CC
DET
PG
TPG
REM
CMOS IC
PIN DESCRIPTION
PIN NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
PIN NAME
V33
V5
V12
PT
GND
CT
C1
C2
REM
TPG
PG
DET
V
CC
OPOUT
OPNEGIN
V
ADJ
TYPE
I
I
I
I
P
O
O
I
O
I
P
O
I
I
FUNCTIONS
OVP/UVP Input For 3.3V
OVP/UVP Input For 5V
OVP/UVP Input For 12V
Additional OVP Protection
Ground
Cap FOR Osciilation Frequency
Output 1
Output 2
Remote ON/OFF Pin.
Power Good Delay Time Setting
Power Good Signal Out.
Power Good Signal Detection Input
Supply Voltage For IC
OP AMP Output
OP AMP Negative Input
Voltage Adjust Pin
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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QW-R502-034. D
3521
BLOCK DIAGRAM
CMOS IC
UNISONIC TECHNOLOGIES CO., LTD
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QW-R502-034. D
3521
ABSOLUTE MAXIMUM RATINGS
(V
CC
=5.5V, unless otherwise specified)
PARAMETER
CMOS IC
SYMBOL
RATINGS
UNIT
Supply Voltage
V
CC
5.5
V
Drain Output Voltage
V
CC
1, V
CC
2
5.5
V
Drain Output Current
I
CC
1, I
CC
2
200
mA
Power Dissipation
P
D
200
mW
Operating Temperature
T
OPR
-10 ~ +70
℃
Storage Temperature
T
STG
-65 ~ +150
℃
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
ELECTRICAL CHARACTERISTICS
(Ta=25℃, V
CC
=5V, unless otherwise specified)
PARAMETER
DEAD TIME CONTROL SECTION
Input Threshold Voltage
ERROR AMP SECTION
Opneg Bias Voltage
Close Loop Voltage Gain
Cross Over Point
OUTPUT SECTION
Output Saturation Voltage
Drain Off-State Current
Rising Time
Falling Time
PROTECTION SECTION
Over Voltage Protection (OVP)
SYMBOL
V
I(THR)
TEST CONDITIONS
ZERO DUTY CYCLE
MAX. DUTY CYCLE
OPNEG OPEN
0.5V ~ 3.5V
0dB
I
D
=200mA
V
CC
=V
D
=V
S
=0V
R
PULL-UP
=1 KΩ
R
PULL-UP
=1 KΩ
3.8
5.8
4.38
1.2
1.78
2.70
2.11
0.54
100
2.0
2.0
30
3.5
0.54
I
PG
=10mA
0.8
5.25
42
5.5
0.70
0.4
2.35
MIN
TYP
3.0
0.1
2.45
65
320
1.1
2
100
50
4.1
6.2
4.64
1.25
1.98
3.00
2.37
0.62
250
MAX UNIT
3.5
V
V
dB
KHz
V
μA
ns
ns
2.55
G
VC
V
DSSAT
I
D(OFF)
t
R
t
F
V33
V5
V12
P
T
V33
V5
V12
P
T
t
DLY
V
IH
V
IL
V
H(PULL)
t
DLY
t
DLY (OFF)
V
I(DET)
V
O(SAT)
I
CHAR
1.3
10
200
200
4.4
6.6
4.90
1.3
2.18
3.30
2.63
0.70
500
V
Under Voltage Protection (UVP)
UVP Disable Voltage
UVP Delay Time
REMOTE ON/OFF SECTION
REM High Input Voltage
REM Low Input Voltage
REM Pull High Voltage
REM Delay Time
REM Off Delay Time
POWER GOOD SECTION
Detecting Input Voltage
Output Saturation Voltage
Charging Current For TPG
PG Output Pull-up Resistor
PG Output Load Resistor
PG Delay Time
TOTAL DEVICE
Standby Supply Current
OSCILLATION SECTION
Oscillation Frequency
Frequency Change With TEMP.
V
V
ms
V
V
V
ms
ms
V
V
μA
KΩ
KΩ
ms
mA
KHz
%
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36
4.5
0.62
0.2
30
5
1
250
10
R
O(PULL-UP))
R
O(LOAD)
t
DLY
C=2.2μF
I
CC
Fosc
Fosc/T
C
T
=2200P
C
T
=2200P
0.5
100
2
500
20
70
50
2
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
QW-R502-034. D
3521
FUNCTION DESCRIPTION
(1) REMOTE ON/OFF
CMOS IC
REM
REMONF
trem
trem
REMON
toff
toff
(2) Under Voltage Protection Delay Time
REM
REMONF
trem
UVP
td,uvp
(3) Pulse Width Modulation
The output pulse width modulation is generated by comparison of the saw-tooth waveform from the capacitor C
T
to the feedback of the voltage.
Therefore, an increase in feedback control signal amplitude causes a linear decrease of the output pulse width.
(4) 0Protection Control of the Soft-Start
The soft-start function is to reduce the large current surge during power-up or preventing the output voltages
(V33/V5/V12) reaches the Over Voltage Protection level.
(5) The function of PT
This signal is prepared for extra Over Voltage Protection Input (V
PT
>1.25V) or another Disable Under Voltage
Protection function (V
PT
<0.62V).
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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QW-R502-034. D
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