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