5101

SENSITRON
SEMICONDUCTOR
SRPC80D28
SRPC100D28
TECHNICAL DATA
DATASHEET 5101, Rev B
28V DC 80AMP and 100AMP
Solid State Power Controller Module
Description:
This Solid State Power Controller (SSPC) Module is a microcontroller-based Solid State Relay designed to be
used in high reliability 28V DC applications. This module has integrated current sensing with no derating over
the full operating temperature range. This module is the electronic equivalent to an electromechanical circuit
breaker with isolated control and status.
SRPC80D28
SRPC100D28
28VDC
28VDC
80A
100A
Latching
Latching
Module Features:
• Extremely Low Power Dissipation, No Derating Over the Full Temperature Range
• Potted Module
• Solid State Reliability
Electrical Features:
•
•
•
•
•
•
•
•
•
•
•
•
28VDC Input with Very Low Voltage Drop; 175 mV, max. @ 100A
True I2t Protection up to 12X rating with Nuisance Trip Suppression
Instant Trip Protection (200 μsec typ)
Unlimited Interrupt Capability; Repetitive Fault Handling Capability
Thermal Memory
Internally Generated Isolated Supply to Drive the Switch
Low Aux Supply Current: 10 mA typ @ 5V DC
High Control Circuit Isolation: 100V DC Control to Power Circuit
Soft Turn-On to Reduce EMC and capacitive load Issues
EMI Tolerant
Input control doubles as reset; Reset Circuit is Trip-Free
TTL/CMOS Compatible, Optically Isolated, Input and Outputs
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 1
SENSITRON
SEMICONDUCTOR
SRPC80D28
SRPC100D28
TECHNICAL DATA
DATASHEET 5101, Rev B
Table 1: Electrical Characteristics (at 25°C and VAUX = 5.0V DC unless otherwise specified)
Control & Status (TTL/CMOS Compatible)
AUX Supply (Vcc)
AUX Supply (Vcc) Current
Status & BIT/TRIP Signals
CONTROL Signal
VIL
VIH
RIN
5.0V DC Nominal, 7V DC Absolute Maximum
4.5V to 5.5 VDC
10 mA typ
20 mA, max
Voh=3.7V, min, at Ioh = -8mA
Vol=0.4V, max, at Iol = 2mA
0.8V, max
2V, min
101 kOhm, typ
Power
Input Voltage – Continuous
– Transient
Max current without tripping
9V to 40V DC, 43V DC Absolute Maximum
+100V or –100V Spike (< 10 µs)
See
Table 5
See
Table 5
See Trip Curve in Figure 1
See
Table 5
110% min
Trip time
See Trip Curve in Figure 1
Power Dissipation
Current
Max Voltage Drop
Protection
Instant Trip
See Trip Curve in Figure 1
Table 2: Physical Characteristics
Temperature
Operating Temperature
Storage Temperature
TA = -40 °C to +100 °C
TA = -55 °C to +125 °C
Environmental
Altitude
Case Dimensions
Weight
Up to 30,000 ft
Can be installed in an unpressurized area
2.00” x 1.95” x 0.44”
400 grams typ, 450 grams max
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 2
SENSITRON
SEMICONDUCTOR
SRPC80D28
SRPC100D28
TECHNICAL DATA
DATASHEET 5101, Rev B
Figure 1: Trip Curve for SRPC80D28 (rated current is 80 Amp)
Figure 2: Trip Curve for SRPC100D28 (rated current is 100 Amp)
ALWAYS
TRIP
NEVER
TRIP
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 3
SENSITRON
SEMICONDUCTOR
SRPC80D28
SRPC100D28
TECHNICAL DATA
DATASHEET 5101, Rev B
Figure 3: Timing Diagram
CONTROL
t4
BIT / TRIP
t5
t0
LOAD VOLTAGE
trip
t2
t7
STATUS
t6
t1
t3
Table 3: Signal Timing (-40°C to 100°C, 28VDC_IN = 28VDC)
Parameter
CONTROL to GATE Status Delay for Turn On
Turn ON Delay
Load Voltage Rise Time
Turn ON to LOAD Status Delay
CONTROL to GATE Status Delay for Turn Off
Turn OFF Delay
Load Voltage Fall Time
Turn OFF to LOAD Status Delay
Symbol
t0
t1
t2
t3
t4
t5
t6
t7
Min
50
50
Max
500
1
200
2
500
1
200
2
Units
μs
ms
μs
ms
μs
ms
μs
ms
Note: Voltage Fall Time from trip is dependent on magnitude of overload
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 4
SENSITRON
SEMICONDUCTOR
TECHNICAL DATA
DATASHEET 5101, Rev B
SRPC80D28
SRPC100D28
All dimensions are in inches
Figure 4: SRPC80D28 Mechanical Dimensions
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 5
SENSITRON
SEMICONDUCTOR
SRPC80D28
SRPC100D28
TECHNICAL DATA
DATASHEET 5101, Rev B
Table 4: Pin Definitions
Pin Number
A
B
C
D
E
F
G
H
J
K
L
M
Pin Name
28V RETURN
AUX. IN (5VDC)
AUX. COMMON
28V RETURN
AUX. IN (5VDC)
AUX. COMMON
CONTROL
STATUS
BIT/TRIP
CONTROL
STATUS
BIT/TRIP
Function
14-30V POWER RETURN
LOGIC POWER 5V POSITIVE
LOGIC POWER RETURN
14-30V POWER RETURN
LOGIC POWER 5V POSITIVE
LOGIC POWER RETURN
Control Input
Load Status Output
Switch Status Output
Control Input
Load Status Output
Switch Status Output
1 (STUD)
2 (STUD)
28V DC, IN
28VDC, LOAD
14-30V POSITIVE
OUTPUT LOAD CONNECTION
Table 5: Model Current Rating, Power Dissipation, Voltage Drop
Model
SRPC80D28
Current
Rating
80 A
Pdiss
25°C
20 W max
Pdiss
100°C
20 W max
Vdrop
25°C
175 mV max
Vdrop
100°C
195 mV max
Figure 5: Electrical Block Diagram
AUX_IN
28VDC_IN
DC-DC
28VDC_RTN
CONTROL
BIT/TRIP
Aux Loss
STATUS
5v 15v Gate
Control
uController
BIT
Status
A/D
G
28VDC_LOAD
AUX_COMMON
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 6
SENSITRON
SEMICONDUCTOR
TECHNICAL DATA
DATASHEET 5101, Rev B
SRPC80D28
SRPC100D28
Description
Figure 5 shows the block diagram of the SRPC80D28. A 74HCT1G04 device is used for the CONTROL input
and the BIT/TRIP and STATUS digital outputs. These digital I/O are TTL and CMOS compatible. The outputs
can each drive more than 1 standard TTL loads. This digital circuitry is optically isolated from the 28V power
and the microcontroller circuitry.
Isolated power for the microcontroller electronics is generated from the DC-DC converter off of the 28VDC_IN
power. This isolated power is referenced to the 28VDC_LOAD output of the SSPC.
Load current is measured by the microcontroller using an integrated A/D, a voltage amplifier, ‘G’, and a current
sense resistor, Rsense. The microcontroller code implements a precision I2t protection curve as well as an
Instant Trip function. This circuit breaker action protects the user application wiring as well as the power
components of the SSPC itself. The microcontroller performs all of the functions of multiple analog comparators
and discrete logic in one high-reliability component. The STATUS output is set active when >10% rated load
current is measured and inactive otherwise.
The I2t software algorithm in the microcontroller performs a reading at the A/D converter, squares this reading,
and applies it to a simulated RC circuit. The algorithm trips the output (turns off the power Mosfets) when the
simulated RC output becomes too high. Because the microcontroller simulates an analog RC circuit, the SSPC
has ‘thermal memory’. That is, it trips faster if there had been current flowing prior to the overload than if there
hadn’t been current flowing. This behavior imitates thermal circuit breakers and better protects the application’s
wiring since the wiring cannot take as much of an overload if current had been flowing prior to the overload.
The CONTROL input is monitored by the microprocessor. When this input is active, the power mosfet is turned
on. When inactive, the mosfet is turned off. The turning on of the mosfet is overridden if an I2t overload or
instant trip condition are detected. In either of these conditions the mosfet is turned off independently of the
CONTROL input and may not be turned on again until a ‘reset’ is performed.
The BIT/TRIP output goes active whenever the mosfet is turned on and inactive whenever the mosfet is turned
off.
The AUX LOSS input is used to detect loss of AUX_IN power. When AUX LOSS is detected, the mosfet state
is held on/off based on the last CONTROL input on/off that was detected.
The microcontroller has a watchdog timer that can detect certain types of failures in software execution. The
software programmed in the microcontroller is set to periodically reset the free running watchdog timer. If the
software malfunctions in such a way that the watchdog timer cannot be reset, the watchdog times out and resets
the processor hardware. The watchdog timer operates from its own internal clock so a failure of the main
internal clock will not stop the watchdog timer. On watchdog timeout the processor will restart just as if 28V
power had been lost and restored. Since the code is designed to detect levels and not edges on the Control
input, the output of the SSPC immediately reflects the state of the Control input after reset.
The Power Mosfets used in the SSPC have been selected for very low Rds(on). This results in low voltage drop
across and low power dissipation in the SSPC. In most applications, the Mosfets will be operated at 50% to
60% of rated current to provide a safety margin. As can be seen in Table 5, when the SRPC80D28 is operated
at 80 Amps, it only dissipates 20 W at room temperature. Each application should be evaluated for heat sinking
requirements at maximum expected constant current. Because the mosfet’s are thermally attached to the
module baseplate, temperature rise from power dissipation may be controlled by headsinking the baseplate.
For overloads, no heat sinking is required provided the SSPC is allowed some time to cool down. The design
has sufficient thermal mass that the temperature will rise only a few degrees under the worst-case overload.
Repetitive overloads should be avoided. When the SSPC reports a trip condition, the controller driving the
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 7
SENSITRON
SEMICONDUCTOR
SRPC80D28
SRPC100D28
TECHNICAL DATA
DATASHEET 5101, Rev B
SSPC should allow no more than four repetitions and then allow thirty seconds to cool down before trying to turn
on again.
The SSPC will trip on overloads in the ALWAYS TRIP region shown in the trip curve of Figure 1. The SSPC will
never trip when operated in the NEVER TRIP region. When overload occurs, the SSPC will trip, turning off the
output mosfet. The SSPC mosfet will remain off until reset. The SSPC can be reset by bringing the CONTROL
pin to a logic low. When the CONTROL pin is brought back to logic high, the SSPC will turn back on. If the
overload is still present, the SSPC will trip again. Removing and reapplying power to the 28VDC_IN pin will also
reset the SSPC. If the CONTROL pin is at logic high when the 28VDC_IN power is cycled off/on, the SSPC will
turn back on when the 28VDC_IN power is re-applied.
Removing AUX_IN power will not change the on;off state of the SSPC mosfet. The last state commanded by
CONTROL will be held until AUX_IN power is reapplied.
Logic Outputs
The STATUS and BIT/TRIP status outputs of the SSPC reflect the operating state of the SSPC. A logic high on
the STATUS output indicates that the current drawn on the 28V_LOAD output is < 10% of rated load. A logic
low shows that the current drawn from the 28V_LOAD output is > 10% of rated current. Because of load
detection tolerances, a load that draws between 5% and 15% of rated current could result in either a high or low
logic level on the STATUS output. Logic high on the BIT/TRIP output indicates that the Power Mosfet switch is
on while a logic low indicates that the switch is off.
As can be seen in Table 6, of the 8 possible states for the combination of CONTROL, STATUS, and BIT/TRIP,
only 4 states represent valid SSPC operation. The other 4 states indicate either a failed SSPC or, more likely, a
short to Aux Common or a short to the AUX supply of one of the logic outputs. By comparing the CONTROL
input with the STATUS and BIT/TRIP outputs, the user can determine whether or not the load is supposed to be
ON, whether or not it’s drawing current, and whether or not the STATUS and BIT/TRIP outputs are valid
responses to the CONTROL input.
State 4 may be used as a normal operating mode for detecting loss of 28VDC IN voltage. Both STATUS and
BIT/TRIP will be logic high if AUX power is applied but 28VDC IN power is not.
Table 6: CONTROL, STATUS & BIT/TRIP Truth Table
State
1
2
3
4
5
6
7
8
CONTROL
L
L
L
L
H
H
H
H
STATUS
L
L
H
H
L
L
H
H
BIT/TRIP
L
H
L
H
L
H
L
H
Comments
SSPC failure or shorted STATUS output to AUX Common
SSPC failure
Normal OFF condition
SSPC failure or 28VDC IN voltage too low
SSPC failure or shorted BIT/TRIP output to AUX Common
Normal ON condition with load current detected
Normal overcurrent trip condition
Normal ON condition with no load current detected
Wire Size
For transient or overload conditions, the transient or overload happens so quickly that heat is not transferred
from the wire to the surroundings. The heat caused by the I2R heating of the wire causes the temperature to
rise at a linear rate controlled by the heat capacity of the wire. The equation for this linear rise in temperature,
with respect to time, can be solved as: I2t = constant. Every wire has an I2t rating that’s dependent on the
temperature rise allowed and the diameter of the wire. If the I2t rating of the SSPC or circuit breaker is less than
the I2t rating of the wire, then the SSPC or circuit breaker can protect the wire.
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 8
SENSITRON
SEMICONDUCTOR
SRPC80D28
SRPC100D28
TECHNICAL DATA
DATASHEET 5101, Rev B
Application Connections
The connections to the SSPC in a typical application are shown in Figure 6.
Figure 6: Typical Application
+
28VDC_IN
DC-DC
28V
28VDC_RTN
AUX_IN
CONTROL
+
5V
APPLICATION
CONTROLLER
BIT/TRIP
28VDC_LOAD
STATUS
AUX_COMMON
Rise Time & Fall Time
The rise and fall times of the SSPC are pre-set at the factory for a nominal 100µS (see Table 3 for min/max
limits).
The 80A SSPC can turn on into a capacitive load of 2000uF without tripping.
Wiring and Load Inductance
Wiring inductance can cause voltage transients when the SSPC is switched off due to an overload. Generally,
these transients are small but must be considered when long wires are used on either the 28VDC IN or 28V
LOAD pins or both. A 10 foot length of wire in free air will cause a transient voltage of about 80 Volts when the
80A SSPC trips at an Instant Trip level of 1200 Amps. At the rated load current of 80 Amps, the voltage
transient will be about 5 Volt. If longer wire lengths are used, a transient suppressor may be used at the 28VDC
IN pin and a power diode may be used at the 28VDC LOAD pin so that the total voltage between these pins is
less than 100 V.
When powering inductive loads, the negative voltage transient at the 28VDC LOAD pin can cause the voltage
between 28VDC IN and 28VDC LOAD to exceed the SSPC rating of 100 Volts and a power diode from the 28V
DC LOAD pin to 28V RETURN must be used. The cathode of the power diode is connected to the 28VDC
LOAD pin with the anode connected to 28V RTN . The power diode must be able to carry the load current when
the SSPC switches off. Voltage transients due to wiring or load inductance are proportional to the operating
current.
Paralleling
For example, putting two 80A SSPCs in parallel will not double the rating to 160 Amps. Due to differences in
the Rds(on) of the Power Mosfets in the SSPCs, the current will not share equally. In addition, there are unit-tounit differences in the trip curves so that two SSPCs in parallel may possibly trip at 120 Amps. Also, both
SSPCs will not trip together; the SSPC carrying the higher current will trip first followed by the other SSPC.
Multiple SSPCs may be used in parallel as long as these complexities are appreciated.
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 9
SENSITRON
SEMICONDUCTOR
TECHNICAL DATA
DATASHEET 5101, Rev B
SRPC80D28
SRPC100D28
Layout
The current-carrying power circuit should be kept well away from the control circuit and other low-level circuits in
the system. It’s unlikely, but possible, that magnetic coupling could affect the control circuit when turning normal
loads on and off. However, in the case of an overload, the magnetic coupling could be 10 times greater than
with normal loads. Effects of such coupling could cause ‘chattering’ when turning on and off, oscillation, and the
possibility of turning the SSPC back on after an overload. The SSPC is a Trip-Free device. Once tripped it will
not turn back on until reset and commanded on again. Reset is accomplished by bringing the CONTROL pin
low and turning the SSPC back on is accomplished by bringing the CONTROL pin high. Sufficient magnetic
coupling between the current-carrying power circuit and the control circuit can negate the Trip-Free
characteristic.
DISCLAIMER:
1- The information given herein, including the specifications and dimensions, is subject to change without prior notice to improve product
characteristics. Before ordering, purchasers are advised to contact the Sensitron Semiconductor sales department for the latest version of the
datasheet(s).
2- In cases where extremely high reliability is required (such as use in nuclear power control, aerospace and aviation, traffic equipment, medical
equipment , and safety equipment) , safety should be ensured by using semiconductor devices that feature assured safety or by means of users’
fail-safe precautions or other arrangement .
3- In no event shall Sensitron Semiconductor be liable for any damages that may result from an accident or any other cause during operation of
the user’s units according to the datasheet(s). Sensitron Semiconductor assumes no responsibility for any intellectual property claims or any
other problems that may result from applications of information, products or circuits described in the datasheets.
4- In no event shall Sensitron Semiconductor be liable for any failure in a semiconductor device or any secondary damage resulting from use at
a value exceeding the absolute maximum rating.
5- No license is granted by the datasheet(s) under any patents or other rights of any third party or Sensitron Semiconductor.
6- The datasheet(s) may not be reproduced or duplicated, in any form, in whole or part, without the expressed written permission of Sensitron
Semiconductor.
7- The products (technologies) described in the datasheet(s) are not to be provided to any party whose purpose in their application will hinder
maintenance of international peace and safety nor are they to be applied to that purpose by their direct purchasers or any third party. When
exporting these products (technologies), the necessary procedures are to be taken in accordance with related laws and regulations.
• 221 West Industry Court Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 •
• World Wide Web - http://www.sensitron.com • E-Mail Address - [email protected] • Page 10
Similar pages