UTC 3521
CMOS IC
UTC
UNISONIC TECHNOLOGIES CO., LTD.
1
www.unisonic.com.tw
QW-R502-034,A
PWM CONTROLLER WITH SUPERVISORY
CIRCUIT FOR SWITCHING POWER
SUPPLY
DESCRIPTION
UTC 3521 PWM controller is designed for switching mode
power supply for PCs etc. It provides all the functions similar
to combinations of industrial 494 plus 3510 circuits.
FEATURES
* Over-voltage protection for 3.3V, 5V and 12V with delay
* Under-voltage detection for 3.3V, 5V and 12V with delay
* Remote ON/OFF function
* Power good circuitry for PCs.
DIP-16
*Pb-free plating product number: 3521L
PIN CONFIGURATION
V33
V5
V12
PT
GND
CT
C1
C2
VADJ
OPNEGIN
OPOUT
DET
PG
TPG
REM
V
CC
UTC 3521
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
PIN DESCRIPTION
PIN NO.
PIN NAME
TYPE
FUNCTIONS
1
V33
I
OVP/UVP INPUT FOR 3.3V
2
V5
I
OVP/UVP INPUT FOR 5V
3
V12
I
OVP/UVP INPUT FOR 12V
4
PT
I
ADDITIONAL OVP PROTECTION
5 GND P
GROUND
6
CT
CAP FOR OSCIILATION FREQUENCY
7 C1 O
OUTPUT
1
8 C2 O
OUTPUT
2
9
REM
I
REMOTE ON/OFF PIN.
10
TPG
POWER GOOD DELAY TIME SETTING
11
PG
O
POWER GOOD SIGNAL OUT.
12
DET
I
POWER GOOD SIGNAL DETECTION INPUT
13
VCC
P
SUPPLY VOLTAGE FOR IC
14
OPOUT
O
OP AMP OUTPUT
15
OPNEGIN
I
OP AMP NEGATIVE INPUT
16
VADJ
I
VOLTAGE ADJUST PIN
UTC 3521
CMOS IC
UTC
UNISONIC TECHNOLOGIES CO., LTD.
2
www.unisonic.com.tw
QW-R502-034,A
BLOCK DIAGRAM
(1)
(2)
(3)
OV
V12
UVP
36mS
Delay
4.5mS
Delay
CT
VADJ
OPOUT
C1
C2
PG
TPG
V33
V5
1.25V
0.625V
(4) PT
(9) REM
(6)
(16)
(15)
(14)
OPNEGIN
(10)
(11)
(7)
(8)
IN
UV
UV
UV
+
-
+
-
+
-
+
-
OV
+
-
OV
+
-
OV
+
-
OVP
250ms delay
OUT
CLR
S Q
R
QN
+
-
+
-
DET
0.625V
(12)
OSC
CLR
+
-
2.45V
+
-
+
-
D Q
C QN
DETCMP
DEAD TIME CONTROLER
PWM CONTROL
PWMCMP
ERROR AMP
4k
REMONF
REMON
QOUT
0.4V
ABSOLUTE MAXIMUM RATINGS
(Vcc=5.5V, unless otherwise noted.)
PARAMETER SYMBOL
RATINGS
UNIT
Supply Voltage
V
CC
5.5 V
Drain output voltage
Vcc1, Vcc2
5.5
V
Drain output current
Icc1, Icc2
200
mA
Power Dissipation
P
D
200 mW
Operating Temperature
T
opr
-10 ~ +70
Storage Temperature
T
stg
-65 ~ +150
UTC 3521
CMOS IC
UTC
UNISONIC TECHNOLOGIES CO., LTD.
3
www.unisonic.com.tw
QW-R502-034,A
ELECTRICAL CHARACTERISTICS
(Ta=25
, V
CC
=5V, unless otherwise noted.)
PARAMETER
SYMBOL TEST
CONDITIONS MIN
TYP
MAX
UNIT
DEAD TIME CONTROL SECTION
Input Threshold Voltage
V
thdt
ZERO DUTY CYCLE
MAX. DUTY CYCLE
3.0
0.1
3.3
V
ERROR AMP SECTION
Close Loop Voltage Gain
0.5V ~ 3.5V
65
dB
Cross Over Point
0dB
320
KHz
Opneg Bias Voltage
OPNEG OPEN
2.38
2.45
2.52
V
OUTPUT SECTION
Output Saturation Voltage
V
dssat
Id=200mA
1.1 1.3
V
Drain Off-State Current
I
doff
Vcc=Vd=Vs=0V
2 10
A
Rising Time
T
r
100
200 ns
Falling Time
T
f
50 200 ns
PROTECTION SECTION
Over Voltage Protection (OVP)
V
33
V
5
V
12
P
T
3.8
5.8
4.41
1.2
4.1
6.2
4.64
1.25
4.3
6.6
4.90
1.3
V
Under Voltage Protection (UVP)
V
33
V
5
V
12
1.78
2.70
2.11
1.98
3.00
2.37
2.18
3.30
2.63
V
UVP Disable Voltage
P
T
0.55
0.62
0.68 V
UVP Delay Time
T
d,uvp
100 250 500 ms
REMOTE ON/OFF SECTION
REM High Input Voltage
V
remh
2.0
V
REM Low Input Voltage
V
reml
0.8 V
REM Pull High Voltage
V
remo
2.0
5.25 V
REM Delay Time
T
rem
30 36 42 ms
REM Off Delay Time
T
off
3.5 4.5 5.5 ms
POWER GOOD SECTION
Detecting Input Voltage
V
det
0.55
0.62 0.68 V
PG Output Pull-up Resistor
R
pup.pg
4
K
PG Output Load Resistor
R
pg
0.5 1 2 K
Charging Current For TPG
I
chg.tpg
30
A
PG Delay Time
T
d.pg
C=2.2
F
100 250 500 ms
Output Saturation Voltage
V
sat.pg
I
pg
=10mA
0.2
0.4
V
TOTAL DEVICE
Standby Supply Current
Icc
10
20
mA
OSCILLATION SECTION
Oscillation Frequency
F
osc
C
T
=2200P 50
60
KHz
Frequency Change With TEMP.
F
osc/T
C
T
=2200P
2
%
UTC 3521
CMOS IC
UTC
UNISONIC TECHNOLOGIES CO., LTD.
4
www.unisonic.com.tw
QW-R502-034,A
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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