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FAN3506
PC SMPS Secondary Side Control IC
Features
Description
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The FAN3506 is complete housekeeping circuitry for use in
the secondary side of PC SMPS (Switched Mode Power
Supply). It contains various functions, which are over
voltage protection including two extra protection inputs,
power supply on/off delay control and power good signal
generator. Especially, it contains a programmable shunt
regulator for output feedback and the reference voltage is
trimmed to ±2%. The FAN3506 is available in 16-DIP.
Few External Components
Low Voltage Operation (Vcc_min=4.5V)
Over Voltage Protection for 3.3V/5V/12V Output
Two Protection Inputs (PT1, PT2)
Fault Protection Output with Open Collector
Power Supply on/off Delay Time Control (PSON)
Latch Function Controlled by PSON and Protection
Power Good Signal Generator with Hysteresis
300ms(Typ) Power Good Delay
Programmable Shunt Regulator Trimmed to ±2%
16-Pin Dual In-line Package (16-DIP-300)
16-DIP
1
Block Diagram
V5
2
V33
1
FPO
VCC
5
V12
3
4
PG
lchg
R1
R3
R5
VCC
PT1
+
+
+
+
+
_
13
14
PT2
S
R6
1.26V
COMP4
_
Q3
3.9V
+
COMP6
1.32V~1.26V
Q1
R
9
_
_
_
+
R8 R10 R12
Q
R4
R2
VCC
R7 R9 R11
1.8V~1.2V
Q2
VCC
lil
PSON
7
+
VCC
lon
VCC
loff
VCC
COMP5
IK
_
+
_
3.2V
_
VCC
VCC
+
COMP3
COMP2
15
+
1.32V~1.26V
1.26V _
16
1.8V~0.6V
1.4V
VREF
8
6
11
TPSON
Rd
PGI
12
GND
10
TPG
Rev. 1.0.2
©2002 Fairchild Semiconductor Corporation
FAN3506
Absolute Maximum Ratings
Parameter
Symbol
Value
Unit
VCC
4.5 ~ 15
V
FPO (Fault Protection Output) Voltage
VFPO
20
V
FPO Maximum Current
IFPO
20
mA
PGI Maximum Voltage
Vpgi
20
V
Io(PG)
20
mA
Supply Voltage
PG Output Maximum Current
Cathode Voltage
Vka
20
V
Cathode Current for IK
IK
1 ~ 30
mA
Power Dissipation
PD
1
W
Operating Temperature Range
TOPR
-25 ~ +80
°C
Storage Temperature
TSTG
-65 ~ +150
°C
Electrical Characteristics
(VCC = 5V, Ta = 25°C, unless otherwise specified)
°
Parameter
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
PROTECTION SECTION
OVP Detecting Voltage for 3.3V
VOVP33
PSON=0V
3.9
4.1
4.3
V
OVP Detecting Voltage for 5V
VOVP5
PSON=0V
5.7
6.1
6.5
V
OVP Detecting Voltage for 12V
VOVP12
PSON=0V
13.6
14.3
15.0
V
Protection Input Voltage 1
Vpt1
PSON=0V
1.21
1.26
1.31
V
Protection Input Voltage 2
Vpt2
PSON=0V
1.21
1.26
1.31
V
PSON Input Threshold Voltage
Vth
PSON=0V : 0V to 2V
1
1.4
1.8
V
PSON Input Open Voltage
Vih
PSON : Open
2
-
5.25
V
PSON=0V
0
-
-1
mA
POWER SUPPLY ON/OFF SECTION (PSON)
PSON Input Low Current
PSON Delay Charging Current
lil
lon
PSON=TPSON=0V
-10
-16
-24
uA
Buffer Output Voltage
VRd
lsink=45uA, 200uA
1.21
1.26
1.31
V
Pin8 Clamping Voltage
V8max
PSON=0V
2.0
2.2
2.4
V
High Threshold for On/Off Delay (Note1)
VthH
TPSON : 0V to 2.2V
1.6
1.8
2.0
V
Low Threshold for On/Off Delay (Note2)
VthL
TPSON : 2.2V to 0V
0.4
0.6
0.8
V
Power Supply ON Delay Time (Note3)
Ton
Cpin8=0.22µF, Rd=28kΩ
16
26
36
msec
Toff
Cpin8=0.22µF, Rd=28kΩ
4
8
14
msec
FPO Saturation Voltage
Power Supply OFF Delay Time (Note4)
Vsat(FPO)
lo=10mA
-
0.2
0.4
V
FPO Leakage Current
lleak(FPO)
FPO=20V
0
0.01
1
uA
3
