SG1548/SG2548/SG3548
QUAD POWER FAULT MONITOR
DESCRIPTION
The SG1548 is an integrated circuit capable of monitoring up to four
positive DC supply voltages simultaneously for overvoltage and
undervoltage fault conditions. An on-chip inverting op amp also
allows monitoring one negative DC voltage. The fault tolerance
window is accurately programmable from ±5% to ±40% using a simple
divider network on the 2.5V reference. A single external capacitor sets
the fault indication delay, eliminating false outputs due to switching
noise, logic transition current spikes, and short-term AC line interrup-
tions. An additional comparator referenced to 2.5V allows the AC line
to be monitored for undervoltage conditions or for generation of a line
clock. The comparator can also be used for programmable
undervoltage lockout in a switching power supply. Uncommitted
collector and emitter outputs permit both inverting and non-inverting
operation. External availability of the precision 2.5V reference and
open-collector logic outputs permit expansion to monitor additional
voltage using available open-collector quad comparators.
FEATURES
•
•
•
•
•
•
•
•
•
•
Monitors four DC voltages and the AC line
Precision 2.5V ±1% low-drift reference
Fault tolerance adjustable from ±5% to ±40%
±3% trip threshold tolerance over temperature
Separate 10mA, 40V overvoltage, undervoltage
and AC line fault outputs
Fault delay programmable with a single capacitor
30mV comparator hysteresis to prevent oscilla-
tions
On-chip inverting op amp for negative voltage
Open-collector output logic or expandability
Operation from 4.5V to 40V supply
HIGH RELIABILITY FEATURES - SG1548
♦
Available to MIL-STD-883
♦
LMI level "S" processing available
♦
BLOCK DIAGRAM
11/91 Rev 1.3
9/02
Copyright
©
1997
1
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG1548/SG2548/SG3548
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Supply Voltage (+V
IN
) .......................................................... 40V
Fault Output Collector Voltage ............................................ 40V
Sense Input Voltage Range ................................. -0.3V to 6.0V
Fault Output Sink Current ................................................ 20mA
Line Sense Input Current ................................................. ±1mA
Inverting Op Amp Input Current ........................................ -5mA
Note 1. Values beyond which damage may occur.
Inverting Op Amp Output Current .................................... 25mA
Operating Junction Temperature
Hermetic (J, L Packages) ............................................. 150°C
Plastic (N, DW Packages) ............................................ 150°C
Storage Temperature Range ............................ -65°C to 150°C
Lead Temperature ........................................................... 300°C
THERMAL DATA
J Package:
Thermal Resistance-
Junction to Case
,
θ
JC
................... 30°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
.............. 80°C/W
N Package:
Thermal Resistance-
Junction to Case
,
θ
JC
.................. 40°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
............. 65°C/W
DW Package:
Thermal Resistance-
Junction to Case
,
θ
JC
.................. 40°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
............. 95°C/W
L Package:
Thermal Resistance-
Junction to Case
,
θ
JC
.................. 35°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
........... 120°C/W
Note A. Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
Note B. The above numbers for
θ
JC
are maximums for the limiting
thermal resistance of the package in a standard mount-
ing configuration. The
θ
JA
numbers are meant to be
guidelines for the thermal performance of the device/pc-
board system. All of the above assume no ambient
airflow.
RECOMMENDED OPERATING CONDITIONS
(Note
2)
Supply Voltage Range
±25% Maximum Fault Window
(Note 3)
.............. 4.5V to 35V
±40% Maximum Fault Window ........................... 5.0V to 35V
Lower Threshold Input Range ............................. 1.5V to 2.45V
Fault Tolerance Window Range .......................... ±5% to ±40%
Fault Output Sink Current Range ............................. 0 to 10mA
Note 2. Range over which the device is functional.
Line Sense Output Current Range ........................... 0 to 10mA
Voltage Reference Output Current ........................... 0 to 10mA
Operating Ambient Temperature Range
SG1548 ......................................................... -55°C to 125°C
SG2548 ........................................................... -25°C to 85°C
SG3548 ............................................................... 0°C to 70°C
Note 3. Limited by inverter amplifier positive swing at -55°C.
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperatures for SG1548 with -55
°C ≤
T
A
≤
125°C, SG2548 with
-25°C
≤
T
A
≤
85°C, SG3548 with 0°C
≤
T
A
≤
70°C, and +V
IN
= 15V. Low duty cycle pulse testing techniques are used which maintains junction and case
temperatures equal to the ambient temperature.)
Parameter
Supply Section
Supply Current
Reference Section
(Note 4)
Output Voltage
Line Regulation
Load Regulation
Short Circuit Current
Fault Window Generator Section
Input Bias Current
DC Sense Inputs Section
Overvoltage Threshold
Undervoltage Threshold
Input Bias Current
Threshold Supply Rejection
Note 4. I
L
= 0mA
Test Conditions
+V
IN
= 40V
T
J
= 25°C
Over Temperature
+V
IN
= 4.5V to 35V
I
L
= 0 to 10mA
V
REF
= 0V
V
PIN 1
= 1.5V to 2.45V
V
PIN 1
= 0.95 x V
REF
V
PIN 1
= 0.60 x V
REF
V
PIN 1
= 0.95 x V
REF
V
PIN 1
= 0.60 x V
REF
V
SENSE
= 1.5V to 3.5V
+V
IN
= 4.5V to 35V
SG1548/2548
SG3548
Units
Min. Typ. Max. Min. Typ. Max.
4.8
10
4.8
10
mA
V
V
mV
mV
mA
µA
V
V
V
V
µA
dB
2.475 2.500 2.525 2.475 2.500 2.525
2.550 2.450
2.550
2.450
1
5
1
5
3
10
3
10
50
50
25
10
25
10
-0.4
-2.0
-0.4
-2.0
2.547 2.625 2.704 2.547 2.625 2.704
3.396 3.500 3.606 3.396 3.500 3.606
2.304 2.375 2.447 2.304 2.375 2.447
1.455 1.500 1.545 1.455 1.500 1.545
±0.6 ±2.0
±0.6 ±2.0
60 100
60 100
11/91 Rev 1.3
9/02
Copyright
©
1997
2
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG1548/SG2548/SG3548
ELECTRICAL CHARACTERISTICS
Parameter
Fault Delay Section
Comparator Threshold
Comparator Hysteresis
Delay Charging Current
On Saturation Voltage
OFF Clamp Voltage
Inverting Op Amp Section
(Note 5)
Input Offset Voltage
Input Bias Current
Output High Voltage
Output Low Voltage
Large Signal Voltage Gain
Output Source Current
Power Supply Rejection Ratio
AC Line Sense Section
Comparator Threshold
Comparator Hysteresis
Input Bias Current
Collector Leakage Current
Collector Saturation Voltage
Emitter Output Voltage
Diode Clamp Voltage
(continued)
Test Conditions
SG1548/2548
SG3548
Units
Min. Typ. Max. Min. Typ. Max.
1.200 1.250 1.300 1.200 1.250 1.300
25
25
32.5 50 67.5 32.5 50 67.5
0.1 0.2
0.1 0.2
+3.2 +3.6
+3.2 +3.6
2
15
-0.3 -1.0
3.5
1.0 1.9
100
15
25
100
2
-0.3
3.5
1.0
100
15
100
15
-1.0
1.9
25
V
mV
µA
V
V
mV
µA
V
V
dB
mA
dB
V
mV
µA
µA
V
V
V
V
µA
V
V
PIN 8
= 0V
I
PIN 8
= 0mA
I
PIN 8
= 0mA
I
SOURCE
= 5mA
I
SINK
= 5mA
R
L
= 10K
+V
IN
= 4.5V to 35V
V
PIN 5
= Low to High
V
PIN 5
= 2.5V
V
CE
= 40V
I
C
= 10mA
I
E
= 10mA
I
PIN 5
= 1mA
I
PIN 5
= -1mA
3.2
72
5
72
3.2
72
5
72
2.440 2.500 2.560 2.440 2.500 2.560
25
25
2
1
1
2
1
10
1
10
0.2 0.5
0.2 0.5
12
13
12
13
6.0
7.5
7.5 6.0
-1.0 -0.3
-1.0
-0.3
1
0.2
10
0.5
1
0.2
10
0.5
Fault Logic Outputs (Each output)
Collector Leakage Current
V
C
= 40V
Collector Saturation Voltage
I
C
= 10mA
Note 5. +V
IN
= 4.5V.
APPLICATION INFORMATION
SETTING THE FAULT TOLERANCE WINDOW
The fault tolerance window is set by applying a voltage less than
the +2.50Vreference to the Lower Threshold input (Pin 1). The
voltage is obtained by a resistor divider from the reference (Pin 3)
to ground. If ±5% tolerance is desired, then 95% of the reference
(+2.375V) is applied to Pin 1. If ±40% is wanted, then 60% of the
reference (+1.50V) is applied. In the example on the back page,
the tolerance is ±5%. The nominal overvoltage and undervoltage
thresholds are centered about the reference at +2.625V and
+2.375V (+2.500V ±0.125V).
SCALING THE MONITORED SUPPLY VOLTAGES
Each positive voltage to be monitored is divided down to +2.50V
with a resistor network and connected to one of the Sense inputs.
Unused Sense inputs should be connected to the reference. This
will not increase the bias current. A variation of the monitored
voltages out of the programmed tolerance range will cause the
appropriate overvoltage or undervoltage fault output to switch
LOW. The effective tolerance on any input may be broadened
with an additional resistor to the voltage reference. The example
on the back page shows a ±10% tolerance on the +5Vsupply
although the SG1548 is programmed for a ±5% tolerance. The
procedure for calculating the resistor value is found in the
SG1548 Application Note.
11/91 Rev 1.3
9/02
Copyright
©
1997
MONITORING A NEGATIVE VOLTAGE
A negative voltage can be converted to a positive one and
simultaneously scaled to +2.50V by using the internal operational
amplifier as an inverter. Only an input resistor and feedback
resistor are required.
SETTING THE FAULT DELAY
A single capacitor at the Delay pin sets the time an out-of-
tolerance fault must persist before a fault is actually declared.
This feature allows switching noise on the supplies to be rejected.
The delay time is given by: Delay = 25ms/µF .
AC LINE MONITORING
The AC line voltage can be monitored for single-cycle dropouts
with the few components shown in the example. A half-wave
rectifier charges the capacitor on positive line cycles. After the
positive peak and during the negative line cycle the capacitor
discharges from a fixed voltage controlled by the internal Zener
diode. If a positive cycle is missing, the capacitor discharges to
below the +2.5V trip point of the comparator, causing the output
transistor to turn on.
3
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG1548/SG2548/SG3548
APPLICATION EXAMPLE
In this example, the SG1548 simultaneously monitors four DC voltages: +5V, +24V, and ±15V. Three different fault tolerances are
programmed: ±5% on the two 15V supplies, ±10% on the +5V supply, and ±20% on the +24V supply. The 5µF delay capacitor provides
125 milliseconds of fault delay.
CONNECTION DIAGRAMS & ORDERING INFORMATION
Package
16-PIN CERAMIC DIP
J - PACKAGE
(See Notes Below)
Part No.
SG1548J/883B
SG1548J
SG2548J
SG3548J
SG2548N
SG3548N
SG2548DW
SG3548DW
Ambient
Temperature Range
-55°C to 125°C
-55°C to 125°C
-25°C to 85°C
0°C to 70°C
-25°C to 85°C
0°C to 70°C
-25°C to 85°C
0°C to 70°C
Connection Diagram
LOWER THRESHOLD
GROUND
V
REF
+V
IN
LINE SENSE
EMITTER OUTPUT
COLLECTOR OUTPUT
DELAY
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
INV. OUTPUT
INV. INPUT
SENSE 4
SENSE 3
SENSE 2
SENSE 1
U.V. FAULT
O.V. FAULT
16-PIN PLASTIC DIP
N - PACKAGE
16-PIN WIDE BODY
PLASTIC S.O.I.C.
DW - PACKAGE
LOWER THRESHOLD
GROUND
V
REF
+V
IN
LINE SENSE
EMITTER OUTPUT
COLLECTOR OUTPUT
DELAY
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
INV. OUTPUT
INV. INPUT
SENSE 4
SENSE 3
SENSE 2
SENSE 1
U.V. FAULT
O.V. FAULT
20-PIN CERAMIC (LCC)
LEADLESS CHIP CARRIER
L- PACKAGE
SG1548L/883B
SG1548L
-55°C to 125°C
-55°C to 125°C
1. N.C.
2. LOWER THRESHOLD
3. GROUND
4. V
REF
5. +V
IN
6. N.C.
7. LINE SENSE
8. EMITTER OUTPUT
9. COLLECTOR
OUTPUT
10.DELAY
3
2
1
20 19
4
5
6
7
8
18
17
16
15
14
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
N.C.
O.V. FAULT
U.V. FAULT
SENSE 1
SENSE 2
N.C.
SENSE 3
SENSE 4
INV. INPUT
INV. OUTPUT
9
10 11 12 13
Note 1. Contact factory for JAN and DESC product availability.
2. All parts are viewed from the top.
11/91 Rev 1.3
9/02
Copyright
©
1997
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
4
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