SG1543/SG2543/SG3543
POWER SUPPLY OUTPUT SUPERVISORY CIRCUIT
DESCRIPTION
This monolithic integrated circuit contains all the functions necessary to monitor and
control the output of a sophisticated power supply system. Over-voltage (O.V.) sensing
with provision to trigger an external SCR “crowbar” shutdown; an under-voltage (U.V.)
circuit which can be used to monitor either the output or to sample the input line voltage;
and a third op amp/comparator usable for current sensing (C.L.) are all included in this
IC, together with an independent, accurate reference generator.
Both over and under-voltage sensing circuits can be externally programmed for mini-
mum time duration of fault before triggering. All functions contain open collector outputs
which can be used independently or wire-ORed together; and although the SCR trigger
is directly connected only to the over-voltage sensing circuit, it may be optionally
activated by any of the other outputs, or from an external signal. The O.V. circuit also
includes an optional latch and external reset capability.
The current sense circuit may be used with external compensation as a linear amplifier
or as a high gain comparator. Although nominally set for zero input offset, a fixed
threshold may be added with an external resistor. Instead of current limiting, this circuit
may also be used as an additional voltage monitor.
The reference generator circuit is internally trimmed to eliminate the need for external
potentiometers and the entire circuit may be powered directly from either the output being
monitored or from a separate bias voltage.
FEATURES
•
Over-voltage, under-voltage, and
current sensing circuits all
included
•
Reference voltage trimmed to 1%
accuracy
•
SCR "Crowbar" drive of 300mA
•
Programmable time delays
•
Open-collector outputs and
remote activation capability
•
Total standby current less than
10mA
HIGH RELIABILITY FEATURES
- SG1543
♦
Available to MIL-STD-883 and
DESC SMD
♦
LMI level "S" processing avail-
able
BLOCK DIAGRAM
11/91 Rev 1.1 2/94
Copyright
©
1994
1
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG1543/SG2543/SG3543
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Input Supply Voltage (+V
IN
)................................................. 40V
Sense Inputs ...................................................................... +V
IN
SCR Trigger Current
(Note 2)
......................................... 300mA
Indicator Output Voltage ..................................................... 40V
Indicator Output Sink Current ..........................................
Operating Junction Temperature
Hermetic (J, L Packages) ............................................
Plastic (N, DW Packages) ...........................................
Storage Temperature Range ............................ -65°C to
50mA
150°C
150°C
150°C
Note 1. Values beyond which damage may occur.
Note 2. At higher input voltages, a dissipation limiting resistor, R
G
, is required. See Figure 1.
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
3)
Input Supply Voltage (+V
IN
) .................................... 4.7V to 40V
Current Limit Common Mode
Input Voltage Range ....................................... 0V to +V
IN
-3V
Reference Load Current ........................................... 0 to 10mA
Indicator Output Voltage ......................................... 4.7V to 40V
Indicator Output Current ........................................... 0 to 10mA
Delay Timing Capcitor
(Note 4)
..................................... 0 to 1µF
Operating Ambient Temperature Range
SG1543 ......................................................... -55°C to 125°C
SG2543 ........................................................... -25°C to 85°C
SG3543 .............................................................. 0°C to 70°C
Note 3: Range over which the device is functional.
Note 4. Larger value capacitor may be used with peak current limiting. See Figure 7.
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperatures for SG1543 with -55°C
≤
T
A
≤
125°C, SG2543 with
-25°C
≤
T
A
≤
85°C, SG3543 with 0°C
≤
T
A
≤
70°C, and +V
IN
= 10V. Indicator outputs have 2KΩ pull-up resistor. Low duty cycle testing techniques are
used which maintains junction and case temperatures equal to the ambient temperature.)
Parameter
Supply Section
Input Voltage Range
Supply Current
Reference Section
Output Voltage
Line Regulation
Load Regulation
Short Circuit Current
Temperature Stability
Test Conditions
T
J
= 25°C to T
MAX
+V
IN
= 40V, Outputs open, T
J
= 25°C
T
J
= 25°C
+V
IN
= 5 to 30V
I
REF
= 0 to 10mA
V
REF
= 0V
SG1543/2543
SG3543
Units
Min. Typ. Max. Min. Typ. Max.
4.5
4.7
7
40
40
10
4.5
4.7
7
40
40
10
V
V
mA
V
V
mV
mV
mA
%/°C
2.48 2.50 2.52 2.45 2.50 2.55
2.55 2.40
2.60
2.45
1
5
1
5
1
10
1
10
25
40
12
25
40
12
.005
.005
11/91 Rev 1.1 2/94
Copyright
©
1994
2
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG1543/SG2543/SG3543
ELECTRICAL CHARACTERISTICS
Parameter
Comparator Section
Input Threshold
(Note 5)
Input Hysteresis
Input Bias Current
Delay Saturation
Delay High Level
Delay Charging Current
Indicate Saturation
Indicate Leakage
Propagation Delay
T
J
= 25°C
Sense input = 0V
(continued)
Test Conditions
SG1543/2543
SG3543
Units
Min. Typ. Max. Min. Typ. Max.
2.45 2.50 2.55 2.40 2.50 2.60
2.40
2.60 2.35
2.65
25
25
0.3 1.0
0.3 1.0
0.2 0.5
0.2 0.5
6
8
6
8
200 250 300 200 250 300
0.2 0.5
0.2 0.5
.01 1.0
0.1 1.0
400
10
100
12
200
13
0
0.4
2
0.4
2
400
300
500
400
0.1
0.8
6
0.8
6
100
12
400
10
200
13
0
0.4
2
0.4
2
400
300
500
400
V
V
mV
µA
V
V
µA
V
µA
ns
ms
mA
V
0.1
V
mA
0.8
6
V
0.8
mA
6
V
mA/µs
ns
ns
V
µA
mV
mV
dB
dB
V
µA
MHz
ns
V
D
= 0V
I
L
= 10mA
V
IND
= 40V
V
O.V. INPUT
= 2.7V, V
U.V. INPUT
= 2.3V , T
J
= 25°C
C
D
= 0
C
D
= 1µF
+V
IN
= 5V, R
G
= 0, V
O
= 0
+V
IN
= 15V, I
O
= 100mA
+V
IN
= 40V, R
L
= 1KΩ
REM. ACT. pin = Gnd
REM. ACT pin open
RESET pin = Gnd, REM. ACT. = Gnd
RESET pin open, REM. ACT. = Gnd
R
L
= 50Ω, T
J
= 25°C, C
D
= 0
V
REM. ACT.
= 0.4V
V
O.V. INPUT
= 2.7V
SCR Trigger Section
Peak Output Current
Peak Output Voltage
Output Off Voltage
Remote Activate Current
Remote Activate Voltage
Reset Current
Reset Voltage
Output Current Rise Time
Prop. Delay from REM. ACT. Pin
Prop. Delay fom O.V. INPUT Pin
Current Limit Section
Input Voltage Range
Input Bias Current
Input Offset Voltage
CMRR
AVOL
Output Saturation
Output Leakage
Small Signal Bandwidth
Propagation Delay
0
OFFSET/COMP pin open, V
CM
= 0V
OFFSET/COMP pin open, V
CM
= 0V,
10kΩ from OFFSET/COMP pin to Gnd,T
J
=25°C
0
≤
V
CM
≤
12V, V
IN
= 15V
OFFSET/COMP pin open, V
CM
= 0V
I
L
= 10mA
V
IND
= 40V
A
V
= 0dB, T
J
= 25°C
V
OVERDRIVE
= 100mV, T
J
= 25°C
0.3
0
100
70
80
0.2
.01
5
200
V
IN
-3V
0
0.3
0
100
70
80
0.2
.01
5
200
V
IN
-3V
80
60
72
1.0
10
120
70
60
72
1.0
15
130
0.5
1.0
0.5
1.0
Note 5. Input voltage rising on O.V. Input and falling on U.V. Input.
CHARACTERISTIC CURVES
FIGURE 1.
SCR TRIGGER POWER LIMITING
FIGURE 2 .
ACTIVATION DELAY VS. CAPACITOR VALUE
11/91 Rev 1.1 2/94
Copyright
©
1994
3
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG1543/SG2543/SG3543
CHARACTERISTIC CURVES
(continued)
FIGURE 3.
COMPARATOR INPUT HYSTERESIS
FIGURE 4.
CURRENT LIMIT INPUT THRESHOLD
FIGURE 5.
CURRENT LIMIT AMPLIFIER GAIN
FIGURE 6.
CURRENT LIMIT AMPLIFIER FREQUENCY RESPONSE
APPLICATION INFORMATION
FIGURE 7 - SURGE LIMIT CIRCUIT FOR LARGE DELAY CAPACITORS
FIGURE 8 - INPUT LINE MONITOR
The 100 ohm resistor limits the peak discharge current into the
SG1543 while the external PNP transistor provides a high peak-
current discharge path for the delay capacitor.
11/91 Rev 1.1 2/94
Copyright
©
1994
4
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG1543/SG2543/SG3543
APPLICATION INFORMATION
(continued)
The values for the external components are
determined as follows:
1000
Current limit input threshold, V
TH
≈
R
1
C
S
is determined by the current loop dynamics
V
TH
V
O
R
2
Peak current to load, I
P
≈
R + R
R
2
+R
3
SC
SC
V
TH
Short circuit current, I
SC
= R
SC
2.5 (R
4
+R
5
+R
6
)
Low output voltage limit, V
O
(Low) =
R
5
+R
6
2.5 (R
4
+R
5
+R
6
)
High output voltage limit, V
O
(High) =
R
6
(
)
Voltage sensing delay, t
D
= 10,000 C
D
FIGURE 9 - TYPICAL APPLICATION CIRCUIT
V
IN
- 5
SCR trigger power limiting resistor, R
G
> 0.2
FIGURE 10 - SENSING MULTIPLE SUPPLY VOLTAGES
FIGURE 11 - OVERCURRENT SHUTDOWN
11/91 Rev 1.1 2/94
Copyright
©
1994
5
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
微控制器 MCU
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