www.docs.chipfind.ru
2002 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev. 1.0.1
Features
PC Power Supply Output Monitor Circuitry
Few External Components
Over Voltage Protection for 3.3V/5V/12V Output
Over Current Protection for 3.3V/5V/12V Output With
Delay Time
Fault Protection Output With Open Collector Output
Power Supply on/off Delay Time Control (PSON)
Power Good Signal Generator With Hysteresis
Open Collector PG Output
300ms Power Good Delay
Current Sense Setting Function With RI
Latch Function Controlled by PSON and Protection Input
16-Pin Dual In-line Package
FPO (Fault Protection Output)
Fault Protection Output indicates the fault condition as
protection signal. When fault state occurs, the main power is
to be turned-off and the PGO signal goes LOW.
NORMAL = "LOW", FAULT = "HIGH"
PGO (Power Good Output)
Power Good Signal Generator is to monitor the voltage level
of power supply for safe operation of a microprocessor
having some delay time at turn-on. The delay time is
prorammed by a timing capacitor connected to TPG pin of
KA3504. The power good output should be low state before
the output voltage is out of regulation at turn-off.
NORMAL = "HIGH", FAULT = "LOW"
Description
The KA3504 is complete output supervisory circuitry
intended for use in the secondary side of the switched mode
power supply. It provides all the functions necessary to
monitor and control the output of the power supply system.
Power good signal generator, Remote on and off control,
some precision protection features against over-voltage and
over-current are implemented. It directly senses all the
output rails for OVP without any external dividers. As for
output control, power good output (PGO) and Fault
Protection output (FPO) are also included. Utilizing a
minimum number of external components, the KA3504
offers a simple and cost effective solution, greatly reducing
PCB board space for power supply system.
OCP (Over Current Protection)
It has precision OCP functions for +3.3V, +5V, +12V
outputs. The block is made up of three comparators with
current source setting function. Two inputs of each OCP
comparator are connected to both sides of output inductor
that is located in the secondary output of SMPS.
OVP (Over Voltage Protection)
It has OVP functions for +3.3V, +5V, +12V outputs.
The circuit is made up of a comparator with three detecting
inputs.
Remote ON/OFF
Remote on/off section is used to control SMPS externally.
If a high signal is supplied to the remote on/off input, FPO
signal becomes a high state and all secondary outputs are
grounded. The remote on/off signal is transferred with some
on-delay and off-delay time of 8ms, 24ms respectively with
0.1
F external capacitor.
KA3504
PC SMPS Supervisory IC
16-DIP
1
KA3504
2
Internal Block Diagram
Absolute Maximum Ratings
Parameter
Symbol
Value
Unit
Supply Voltage
V
CC
15 ~ 30
V
Input Voltage
Vinput
30
V
FPO Voltage
V
FPO
30
V
FPO Maximum Current
I
FPO
20
mA
Operating Temperature
Topr
-20 ~ +85
C
Storage Temperature Range
Tstg
-65 ~ +150
C
Power Dissipation
P
D
1
W
Start Up
Bandgap
Reference
OVP
Detector
S
R
Q
Control
Vref
I
CHG(PROT)
=20uA
1 4
1 5
1 6
Iref*5
(100uA)
COMP1
Iref*5
(100uA)
Iref*5
(100uA)
Vref
I
CHG(PG)
=15uA
5
1 1
Vref
4
6
9
1 2
1 0
1 3
7
8
Iref=20uA
V
BG
=1.26V
Internal
Bias
S
1.25V
COMP7
Q1
Q3
COMP8
1.8V
!"
0.6V
1.8V
!"
0.6V
COMP4
COMP6
COMP5
On/Off
Delay
1.4V
1.8V
!"
0.6V
COMP2
COMP3
Q2
PGO
PGI
FPO
RI
VS12
VS5
VS33
IS12
IS5
IS33
T
PROT
PSON
T
PSON
GND
T
PG
1
2
3
Vcc
KA3504
3
Pin Assignments : KA3504
VS33
8
7
6
5
4
3
2
1
16
15
14
13
12
11
10
9
K
A
3
5
0
4
VS5
VS12
PGI
Vcc
FPO
PSON
T
PSON
T
PG
T
PROT
PGO
RI
GND
IS12
IS5
IS33
KA3504
4
Pin Definitions
Pin No.
Name
Pin Function Description
1
VS33
Over Voltage Protection Input for the 3.3V. It Directly Senses the 3.3V Rail
Without any External Divider.
2
VS5
Over Voltage Protection Input for the 5V. It Directly Senses the 5V Rail Without
any External Divider.
3
VS12
Over Voltage Protection Input for the 12V. It Directly Senses the 12V Rail
Without any External Divider.
4
PGI
Power Good Signal Generator Input. It Should be Supplied From a Bulk
Dependent Voltage in Order to Detect Power on and off State.
5
V
CC
Supply Voltage. Its Recommended Operating Voltage is Ranged from 15V to
30V.
6
FPO
Fault Protection Output (Open Collector Output). This Pin Indicates the Fault
Condition. When Fault State Occurs, the PGO Signal Goes Low.
Normal = 'Low", Fault = "High".
7
PSON
Remote on/off Input. It does TTL Operation and its Threshold Voltage is 1.4V. In
Case of Open Circuit, the Voltage at this Pin is High (5.0V). If PSON = "Low",
then FPO = "Low". It Means the Main SMPS is Working. When PSON = "High or
Open", then FPO = "High" and the main SMPS Stops to Work.
8
T
PSON
Timing pin for PSON Delay. Ton/Toff=8ms/24ms (Typ.) with Cpson=0.1
F
Externally. PSON On Delay Time (Ton) is Measured as PSON Input Goes Low to
High. PSON Off Delay Time (Toff) can be Measured Reversely.
9
PGO
Power Good Output Signal (Open Collector).
PGO = "High" means "Power Good" for Operation and PGO = "Low" Means
"Power Fail".
10
T
PG
Timing pin for PGO delay. TPG = 270ms (Typ.) with CPG = 2.2
F Externally. The
High/low Threshold Voltages are 1.8V/0.6V and the Voltage of pin10 Would be
Charged up to 2.9V for Noise Margin.
11
RI
OCP Current Sense Setting pin. The Reference Voltage at this pin is set to 1.25V
Internally.You can fix the OCP Reference Current by Using RI Resistor.
12
GND
Ground
13
T
PROT
Timing pin for Under Voltage Protection and Over Current Protection Blank-out
time. Its Threshold Voltage is 1.8V and Clamped at 2.9V After full Charging.
Target of Delay Time is 38ms and it is Realized Through External Capacitor
(C=0.47
F).
14
IS12
Current Sense Input for +12V. This pin is Connected to the Current Sensing
Resistor or Inductor. You can Define OCP Offset Voltage for +12V by Using RI
Resistor Externally. If you Connected RI Resistor of 62k
at Pin11 to Ground,
the Reference Current(Iref) Should be 20
A. After that, you can Make a
Constant OCP Offset Voltage (V
OFFSET
= R
O
5
Iref).
In Case the Voltage Drop (=I
O
.
12
R
S
) of the Sense Resistor or Inductor is
Larger than Offset Voltage, FPO Becomes "High" After Some Delay time and the
Main SMPS is Turned-off. So the Over Current level is Determined by Following
Equation. (I
O.12
= V
OFFSET
/ R
S
)
See Application Note for Details.
15
IS5
Current Sense Input for +5V. You can Make the +5V OCP Function as Previous
Method in IS12 (Pin14).
16
IS33
Current Sense Input for +3.3V. You can also Make the +3.3V OCP Function as
Previous Method in IS12 (Pin14).
KA3504
5
Electrical Characteristics
(V
CC
= 20V, -25
C < Ta < 85
C, unless otherwise specified)
Electrical Characteristics
(V
CC
= 20V, -25
C
<
Ta
<
85
C, unless otherwise specified)
Note:
1. It does TTL operation and its threshold voltage is 1.4V.
2. Power Supply ON Delay Time (Ton) is measured as PSON input goes "Low" to "High".
3. Power Supply OFF Delay Time (Toff) is measured as PSON input goes "High" to "Low".
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
PROTECTION SECTION
Over Voltage Protection for 3.3V
V
OVP33
V
PSON
= 0V
3.9
4.1
4.3
V
Over Voltage Protection for 5V
V
OVP5
V
PSON
= 0V
5.7
6.1
6.5
V
Over Voltage Protection for 12V
V
OVP12
V
PSON
= 0V
13.6
14.3
15.0
V
Offset Voltage of OCP Comparator
V
offset
V
PSON
= 0V
-3
-
3
mV
Charging Current for OCP Delay
I
CHG(PROT)
-
-15
-21
-30
A
3.3, 5, 12V Over Current Delay Time
T
D(OCP)
C = 0.47
F
24
38
57
msec
POWER SUPPLU ON/OFF SECTION (PSON
) Note
PSON Input Threshold Voltage
V
TH(PSON)
PSON: "H"
"L"
1
1.4
1.8
V
PSON Open Voltage
V
OPEN(PSON)
PSON: Open
4
-
5.25
V
PSON Input Low Current
I
LOW(PSON)
V
PSON
= 0V
-
-
-1.6
mA
ON Delay Time
T
ON(PSON)
C = 0.1
F
4
8
14
msec
OFF Delay Time
T
OFF(PSON)
C = 0.1
F
16
24
34
msec
FPO SECTION
FPO Saturation Voltage
V
SAT(FPO)
I
FPO
= 10mA
-
0.2
0.4
V
FPO Leakage Current
V
LKG(FPO)
V
FPO
= 20V
-
0.01
1
A
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
POWER GOOD SECTION
PG Input Threshold Voltage
V
IN(PG1)
PG: "H"
"L"
1.20
1.25
1.30
V
Hysteresis Voltage 1
HY1
COMP7
10
40
80
mV
Hysteresis Voltage 2
HY2
COMP4, 6, 8
0.6
1.2
-
V
Charging Current for PG Delay
I
CHG(PG)
-
-9
-14
-22
A
PG Delay Time
T
D(PG)
C = 2.2
F
150
270
450
msec
PG Output Saturation Voltage
V
SAT(PG)
I
PG
= 10mA
-
0.2
0.4
V
TOTAL DEVICE
Stand-by Supply Current
I
CC
-
-
5
10
mA
KA3504
6
Timing / Housekeeping / Control
Remote on/off
Output Voltage
(3.3V, 5V, 12V)
PGO
FPO
Vcc
Power on/off
Stand-by Mode
Operating Mode
Main Power Switch ON
OFF
PGI Detection
Point
PG
Delay
Toff Delay
Ton Delay
PG
Delay
KA3504
7
Test Circuit
F
A
N
3
5
0
4
K
A
3
5
0
4
KA3504
8
Typical Characteristics
0
10
20
30
40
0.000
0.001
0.002
0.003
0.004
0.005
0.006
Icc=4.881mA
Vcc=20V
Icc
I
cc[
A
]
Vcc[V]
3.4
3.6
3.8
4.0
4.2
4.4
4.6
0
5
10
15
20
VOVP33
F
P
O Vol
t
a
g
e[
V]
3.3V Output Voltage[V]
5.4
5.6
5.8
6.0
6.2
6.4
6.6
0
5
10
15
20
VOVP5
F
P
O V
o
l
t
age[
V
]
5V Output Voltage[V]
13.0
13.5
14.0
14.5
15.0
0
5
10
15
20
VOVP12
FP
O
V
o
l
t
age[
V
]
12V Output Voltage[V]
Figure 1. V
CC
- I
CC
Figure 2. Over Voltage Protection for 3.3V
Figure 3. Over Voltage Protection for +5V
Figure 4. Over Voltage Protection for +12V
Figure 5. PS On/Off Delay Current
Figure 6. PG Input Threshold Voltage
0
1
2
3
4
5
-0.000020
-0.000015
-0.000010
-0.000005
0.000000
0.000005
0.000010
ION.OFF
IO
N
.
O
F
F
[
A
]
PSON Voltage[V]
1.0
1.1
1.2
1.3
1.4
1.5
0
5
10
15
20
PGI
PG
O Vo
l
t
age[V
]
PGI Voltage[V]
KA3504
9
Typical Characteristics
(Continued)
Figure 7. Hysteresis Voltage 1
Figure 8. Hysteresis Voltage 2
1.0
1.1
1.2
1.3
1.4
1.5
0
5
10
15
20
HY1
P
G
O
V
o
l
t
age[
V
]
PGI Voltage[V]
1.0
1.1
1.2
1.3
1.4
1.5
0
5
10
15
20
HY1
P
G
O
V
o
l
t
age[
V
]
PGI Voltage[V]
0.0
0.5
1.0
1.5
2.0
2.5
0
5
10
15
20
HY2
P
G
O
V
o
l
t
age[
V
]
TPG Voltage[V]
0.0
0.5
1.0
1.5
2.0
2.5
0
5
10
15
20
HY2
P
G
O
V
o
l
t
age[
V
]
TPG Voltage[V]
KA3504
10
Application Circuit
Vref
FB
C105
Vref
C125
R30
2
1
N
C121
TX4
Q2
R49
R55
3
C126
D8
L6
V5
Vcc
R52
2
1
Vcc1
Lp1
Ls
TX3
L2
V12
C118
R28
2
1
B+
10
SW2
R51
2
1
L5
Q5
C116
Q6
D7
R46
C106
R29
1
C109
D13
Vcc
C107
V5
FPO
Q3
V33
V12
RT2
R45
R47
C115
PWM
IC
Q4
C111
D5
R34
C104
PSON
C113
FPO
C110
C123
D11
R44
R35
D10
8,9
C2
C1
C108
C103
FB
6
R39
2
1
D14
R33
2
1
5
R41
2
1
Vcc
C117
C120
U6
KA7500
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
EA1(+)
EA1(-)
COMP
DTC
Ct
Rt
GND
C1
E1
E2
C2
Vcc
OC
Vref
EA2(-)
EA2(+)
R56
2
1
B+
-
+
D6
2
1
3
4
C114
U4
FAN3504
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
VS33
VS5
VS12
PGI
Vcc
FPO
PSON
Tpson
PGO
Tpg
RI
GND
Tprot
IS12
IS5
IS33
R48
C1
M1
C127
C122
R37
2
D15
L4
R27
2
1
F1
R54
2
1
TX1
R31
D12
R32
2
1
R50
C112
D9
7
R40
L1
L3
PGO
Vcc
R36
V33
U5
C119
R38
2
1
R42
TX2
C124
R53
R43
2
1
C2
P
KA3504
11
Mechanical Dimensions
Package
Dimensions in millimeters
#1
#8
#9
#16
6.40
0.20
7.62
0.300
2.54
0.100
0.252
0.008
0~15
0.25
+0.10
0.05
0.010
+0.004
0.002
3.30
0.30
0.130
0.012
3.25
0.20
0.128
0.008
19.40
0.20
0.764
0.008
19.80
0.780
MAX
5.08
0.200
0.38
0.014
MAX
MIN
0.81
0.032
()
0.46
0.10
0.018
0.004
0.059
0.004
1.50
0.10
16-DIP
KA3504
11/8/02 0.0m 001
Stock#DSxxxxxxxx
2002 Fairchild Semiconductor Corporation
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 THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
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, and (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 a significant injury of the
user.
2. A critical component in 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.
www.fairchildsemi.com
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.
Ordering Information
Product Number
Package
Operating Temperature
KA3504
16-DIP
-25
C ~ +85
C
PDF 
ZIP