SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 Programmable DC Solid State Power Controller Module Description: These Solid State Power Controller (SSPC) Modules are designed to operate without any heatsink requirements. They are microcontroller-based Solid State Relays rated up to 30A designed to be used in high reliability 28V DC applications. These modules have integrated current sensing with no derating over the full operating temperature range. These modules are the electronic equivalent to electromechanical circuit breakers with isolated control and status. This series is supplied in 6 SSPC families, with each family being programmable over a 5:1 current range. SPDP05D28: Programmable from 1A to 5A SPDP10D28: Programmable from 2A to 10A SPDP15D28: Programmable from 3A to 15A SPDP20D28: Programmable from 4A to 20A SPDP25D28: Programmable from 5A to 25A SPDP30D28: Programmable from 6A to 30A Compliant Documents & Standards: MIL-STD-1275B, Notice1 MIL-STD-704F MIL-STD-217F, Notice 2 Characteristics of 28 Volt DC Electrical Systems in Military Vehicles-4/20/04 Aircraft Electrical Power Characteristics 12 March 2004 Reliability Prediction of Electronic Equipment 28 Feb 1995 Module Features: • • • • • • • No additional heat sinking or external cooling required! Extremely Low Power, No Derating Over the Full Temperature Range Low Weight (20 gms) Same Pin Out as Industry Standard SSPCs in a Smaller Outline Epoxy Shell Construction Solid State Reliability High Power Density Electrical Features (SPDPXXD28 Series): • • • • • • • • • • • • • 28VDC Input with Very Low Voltage Drop; 64mV, typ. @15A for SPDP25D28 True I2t Protection up to 10X rating with Nuisance Trip Suppression Instant Trip Protection (50 μsec typ) for Loads Above 10X rating Unlimited Interrupt Capability; Repetitive Fault Handling Capability Thermal Memory Internally Generated Isolated Supply to Drive the Switch Low Bias Supply Current: 25 mA typ @ 5V DC High Control Circuit Isolation: 750V DC Control to Power Circuit Soft Turn-On to Reduce EMC Issues EMI Tolerant Module Reset with a Low Level Signal; Reset Circuit is Trip-Free TTL/CMOS Compatible, Optically Isolated, Input and Outputs Schmitt-Trigger Control Input for Noise Immunity ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 1 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 Table 1 - Electrical Characteristics (at 25 oC and Vbias = 5.0V DC unless otherwise specified) Control & Status (TTL/CMOS Compatible) BIAS (Vcc) BIAS (Vcc) Current GATE Status, Load Status Signals CONTROL Signal VT+ (Positive-going input threshold voltage) VT− (Negative-going input threshold voltage) ΔVT Hysteresis (VT+ VT−) Reset 5.0V DC Nominal, 6.5V DC Absolute Maximum 4.5V to 5.5 VDC 25 mA typ 31 mA, max Voh=3.7V, min, at Ioh=-20mA Vol=0.4V, max, at Iol=20mA 2.0V, min, 3.5V, max 1.2V, min, 2.3V, max 0.6V, min, 1.4V, max Cycle CONTROL Signal Power Input Voltage – Continuous – Transient Power Dissipation Max Voltage Drop Max current without tripping 0 to 40V DC, 55V DC Absolute Maximum +600V or –600V Spike (< 10 µs) See Table 5 See Table 5 See Figure 1, Trip Curve See Table 5 110% min Trip time Output Rise Time (turn ON) Output Fall Time under normal turn-off Output Fall Time under Fault Min Load Requirement See Figure 1, Trip Curve 300 μsec typ 150 usec typ 50 usec typ Nil Current Protection Short Circuit Protection Instant Trip Unlimited 800%, min; 1200%, max Table 2 - Physical Characteristics Temperature Operating Temperature Storage Temperature TA = -55 °C to +100 °C TA = -55 °C to +125 °C Environmental Altitude Case Dimensions Operating Orientation Weight MTBF (Estimate: MIL STD 217F) Up to 30,000 ft Can be installed in an unpressurized area 1.875”L x 1.125”W x 0.385”H Any 30 grams typ 1.1 Mhrs at 25°C Full load Note: Extreme temperature performance at -55C is only guaranteed if the bias power is left ON while the unit is being cooled. The product family has a guaranteed low temperature performance down to -20C below which some units may exhibit higher bias current (up to 65mA) and unstable Gate and Load Status upon cold start up to 15 seconds. This issue has been addressed and eliminated in a newer version of this product family. Contact factory for further information. ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 2 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 Figure 1 - Trip Curve Figure 2 - Timing Diagram CONTROL t0 t4 SWITCH STATUS t5 LOAD CURRENT t1 t6 t2 t7 LOAD STATUS t3 ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 3 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 Table 3 - Signal Timing – (-55 oC to 100 oC @ LINE = 28V DC) Parameter CONTROL to GATE Status Delay for Turn On Turn ON Delay Load Current Rise Time Turn ON to LOAD Status Delay CONTROL to GATE Status Delay for Turn Off Turn OFF Delay Load Current Fall Time Turn OFF to LOAD Delay Symbol t0 t1 t2 t3 t4 t5 t6 t7 Min (μs) 80 150 175 750 125 175 50 300 Max (μs) 300 325 250 1500 375 325 100 500 Note: Current Fall Time from trip dependent on magnitude of overload Figure 3 - Mechanical Dimensions All dimensions are in inches ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 4 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 Table 4 - Pin Definitions Pin Number 1 2 3 4 5 6 7 8 9 10 Pin Name BIAS GND GATE Status LOAD Status CONTROL Input LINE GAINRET PWRGND GAIN LOAD Function +5V DC Supply 5V Return Switch Status Load Current Detection On/Off Control +28V DC Supply Internally connected to LOAD (pin 10) 28V Return Gain Adjust Load Connection Table 5 – Individual Model Ratings SPDP05D28 Current Rating @ 100OC Power Dissipation (including Control Power) Max Voltage Drop SPDP05D28 Set for 1.0 Amp Rating SPDP05D28 Set for 2.5 Amp Rating SPDP05D28 Set for 5 Amp Rating 1.0A 0.18W typ @ 0.6A 25OC 0.19W max @ 1A 25OC 0.19W max @ 1A 100OC 9mV typ @ 0.6A 25OC 15mV max @ 1A 25OC 17mV max @ 1A 100OC 2.5A 0.21W typ @ 1.5A 25OC 0.27W max @ 2.5A 25OC 0.28W max @ 2.5A 100OC 22mV typ @ 1.5A 25OC 36mV max @ 2.5A 25OC 42mV max @ 2.5A 100OC 5A 0.31W typ @ 3A 25OC 0.54W max @ 5A 25OC 0.59W max @ 5A 100OC 44mV typ @ 3A 25OC 73mV max @ 5A 25OC 83mV max @ 5A 100OC SPDP10D28 Set for 2.0 Amp Rating SPDP10D28 Set for 5 Amp Rating SPDP10D28 Set for 10 Amp Rating 2.0A 0.19W typ @ 1.2A 25OC 0.21W max @ 2A 25OC 0.22W max @ 2A 100OC 11mV typ @ 1.2A 25OC 19mV max @ 2A 25OC 23mV max @ 2A 100OC 5A 0.26W typ @ 3A 25OC 0.41W max @ 5A 25OC 0.47W max @ 5A 100OC 29mV typ @ 3A 25OC 48mV max @ 5A 25OC 58mV max @ 5A 100OC 10A 0.52W typ @ 6A 25OC 1.13W max @ 10A 25OC 1.34W max @ 10A 100OC 57mV typ @ 6A 25OC 95mV max @ 10A 25OC 117mV max @ 10A 100OC SPDP15D28 Set for 3.0 Amp Rating SPDP15D28 Set for 7.5 Amp Rating SPDP15D28 Set for 15 Amp Rating 3.0A 0.20W typ @ 1.8A 25OC 0.24W max @ 3A 25OC 0.26W max @ 3A 100OC 14mV typ @ 1.8A 25OC 23mV max @ 3A 25OC 29mV max @ 3A 100OC 7.5A 0.33W typ @ 4.5A 25OC 0.60W max @ 7.5A 25OC 0.72W max @ 7.5A 100OC 34mV typ @ 4.5A 25OC 56mV max @ 7.5A 25OC 73mV max @ 7.5A 100OC 15A 0.78W typ @ 9A 25OC 1.87W max @ 15A 25OC 2.35W max @ 15A 100OC 68mV typ @ 9A 25OC 113mV max @ 15A 25OC 145mV max @ 15A 100OC SPDP10D28 Current Rating @ 100OC Power Dissipation (including Control Power) Max Voltage Drop SPDP15D28 Current Rating @ 100OC Power Dissipation (including Control Power) Max Voltage Drop ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 5 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 SPDP20D28 Current Rating @ 100OC Power Dissipation (including Control Power) Max Voltage Drop SPDP20D28 Set for 4.0 Amp Rating SPDP20D28 Set for 10 Amp Rating SPDP20D28 Set for 20 Amp Rating 4.0A 0.21W typ @ 2.4A 25OC 0.26W max @ 4A 25OC 0.28W max @ 4A 100OC 13mV typ @ 2.4A 25OC 21mV max @ 4A 25OC 26mV max @ 4A 100OC 10A 0.36W typ @ 6A 25OC 0.70W max @ 10A 25OC 0.83W max @ 10A 100OC 32mV typ @ 6A 25OC 53mV max @ 10A 25OC 65mV max @ 10A 100OC 20A 0.93W typ @ 12A 25OC 2.28W max @ 20A 25OC 2.80W max @ 20A 100OC 63mV typ @ 12A 25OC 105mV max @ 20A 25OC 131mV max @ 20A 100OC SPDP25D28 Set for 5.0 Amp Rating SPDP25D28 Set for 12.5 Amp Rating SPDP25D28 Set for 25 Amp Rating 5.0A 0.21W typ @ 3A 25OC 0.28W max @ 5A 25OC 0.31W max @ 5A 100OC 13mV typ @ 3A 25OC 21mV max @ 5A 25OC 28mV max @ 5A 100OC 12.5A 0.41W typ @ 7.5A 25OC 0.84W max @ 12.5A 25OC 1.04W max @ 12.5A 100OC 32mV typ @ 7.5A 25OC 53mV max @ 12.5A 25OC 69mV max @ 12.5A 100OC 25A 1.13W typ @ 15A 25OC 2.84W max @ 25A 25OC 3.64W max @ 25A 100OC 64mV typ @ 15A 25OC 107mV max @ 25A 25OC 139mV max @ 25A 100OC SPDP30D28 Set for 6.0 Amp Rating SPDP30D28 Set for 15 Amp Rating SPDP30D28 Set for 30 Amp Rating 6.0A 0.23W typ @ 3.6A 25OC 0.33W max @ 6A 25OC 0.37W max @ 6A 100OC 15mV typ @ 3.6A 25OC 26mV max @ 6A 25OC 33mV max @ 6A 100OC 15A 0.52W typ @ 9A 25OC 1.13W max @ 15A 25OC 1.42W max @ 15A 100OC 38mV typ @ 9A 25OC 64mV max @ 15A 25OC 83mV max @ 15A 100OC 30A 1.55W typ @ 18A 25OC 4.01W max @ 30A 25OC 5.16W max @ 30A 100OC 77mV typ @ 18A 25OC 123mV max @ 30A 25OC 166mV max @ 30A 100OC SPDP25D28 Current Rating @ 100OC Power Dissipation (including Control Power) Max Voltage Drop SPDP30D28 Current Rating @ 100OC Power Dissipation (including Control Power) Max Voltage Drop ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 6 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 Figure 5 - Electrical Block Diagram GAIN GAIN RTN Description Figure 5 shows the block diagram of the SPDPXXD28 SSPC Series. It uses a SN74LVC3G14 device for digital I/O. This TTL compatible device has a Schmitt-Trigger input to minimize the effects of noise on the input. Its outputs can each drive more than 10 standard TTL loads. It’s also compatible with CMOS inputs and outputs. The SN74LVC3G14 is isolated from the remainder of the module circuitry by three optocouplers. The block labeled “Control & Protection Circuitry” gets power from the DC-DC converter and is referenced to the output of the SSPC. This block contains an amplifier to gain up the voltage developed across the sense resistor. It also contains a microcontroller with on-board timers, A/D converter, clock generator and independent watchdog timer. The microcontroller implements a precision I2t protection curve as well as an Instant Trip function to protect the wiring and to protect itself. It performs all of the functions of multiple analog comparators and discrete logic in one high-reliability component. The “Control & Protection Circuitry” block also has the ability to adjust the current rating of each model of the SPDPXXD28 Series over a 5:1 range. If the “Gain” terminal is left open, the SSPC will be set for maximum rating. If the “Gain” terminal is connected directly to the “Gain Return” terminal, the SSPC will be set for 1/5 of the maximum rating. Furthermore, a resistor connected between the “Gain” terminal and the “Gain Return” terminal will set a rating between maximum and 1/5 of maximum. See Figure 10 for the relationship between rating and resistor value. ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 7 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 The code programmed in the microcontroller acquires the output of the internal A/D converter, squares the result and applies it to a simulated RC circuit. It checks the output of the simulated circuit to determine whether or not to trip (turn off the power Mosfets). 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 an overload if current had been flowing prior to the overload. The watchdog timer operates from its own internal clock so a failure of the main clock will not stop the watchdog timer. The code programmed in the microcontroller will periodically reset the watchdog timer preventing it from timing out. If the code malfunctions for any reason, the watchdog timer is not reset and it times out. When the watchdog timer times out, it resets the microcontroller. Since the code is designed to detect levels and not edges, the output of the module, and therefore the output of the SPDPXXD28, immediately reflects the command on its input. The Power Mosfets used in the SPDPXXD28 Series have been selected for very low Rds(on) and results in low voltage drop and low power dissipation. In most applications, the SPDPXXD28 will be operated at 50 – 60% of rated current to provide a safety margin. As can be seen in Table 1, when the SPDP25D28 is operated at 15 Amps, 60% of rated current, it only dissipates 1.0 Watt at room temperature. No heat sinking is required for this condition. However, if the SPDP25D28 is to be operated at maximum rating and/or at elevated temperatures, the dissipation can exceed 4 Watts and heat sinking is required. Some heat sinking can be accomplished by adding copper area to the LINE and LOAD pins, a heatsink can be epoxy attached to the surface of the module or a flat copper or aluminum heatsink can be sandwiched between the SPDP25D28 and the printed circuit board using a thermal pad to maximize heat transfer. Each application should be evaluated at maximum expected constant current. The lower current models in the SPDPXXD28 Series do not require heat sinking under all conditions. For overloads, no heat sinking is required provided the SPDPXXD28 Series is allowed some time to cool down. The SPDPXXD28 has sufficient thermal mass that the temperature will rise only a few degrees under the worstcase overload. Repetitive overloads should be avoided. When the SPDPXXD28 reports a trip condition, the controller driving the SPDPXXD28 should allow no more than four repetitions and then allow thirty seconds to cool down before trying to turn on again. The SPDPXXD28 will trip on overloads in the ALWAYS TRIP region shown in Figure 1 and will never trip when in the NEVER TRIP region. The SPDPXXD28 can be reset by bringing the CONTROL pin to a logic low. When the CONTROL pin is brought back to logic high, the SPDPXXD28 will turn back on. If the overload is still present, the SPDPXXD28 will trip again. Cycling the 5 Volt BIAS power will also reset the SPDPXXD28. If the CONTROL pin is at logic high when the BIAS power is cycled, the SPDPXXD28 will turn back on when the BIAS power is re-applied. Status Outputs The LOAD and GATE status outputs of the SPDPXXD28 show whether or not the load is drawing current and Power Mosfet switch is on. A logic high on the LOAD status output shows that the load draws < 5% of rated load and a logic low shows that the load draws > 15% of rated current. A load that draws between 5% and 15% of rated current could result in either a high or low logic level on the LOAD status output. Logic high on the GATE 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, LOAD and GATE, only 3 states represent valid SSPC operation. The other 5 states indicate either a failed SSPC or, more likely, a short to ground or a short to the BIAS supply of one of the logic outputs. By comparing the CONTROL input with the LOAD and GATE outputs, the user can determine whether or not the load is supposed to be ON (GATE), ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 8 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 whether or not it’s drawing current (GATE) and whether or not the LOAD and GATE outputs are valid responses to the CONTROL input. Table 6 – CONTROL, LOAD & GATE Truth Table State 1 2 3 4 5 6 7 8 CONTROL L L L L H H H H LOAD L L H H L L H H GATE L H L H L H L H Comments SSPC failure or shorted LOAD output to ground SSPC failure Normal OFF condition SSPC failure or shorted GATE output to BIAS supply SSPC failure or shorted GATE output to ground Normal ON condition with load current > 15% rated current Tripped Normal ON condition with load current < 5% rated current Wire Size MIL-W-5088L has a chart the shows wire size as a function of wire temperature and current. This chart is for a single copper wire in free air. For an ambient temperature of 70 oC, the chart allows an 18-gauge wire to handle 25 Amps continuously at a wire temperature of 200 oC – a wire temperature rise of 130 oC. For a wire temperature limited to 150 oC, the chart requires a 16-gauge wire and for a wire temperature of 105 oC, the chart requires a 14-gauge wire. Amendment 1 of MIL-W-5088L has a table for copper wire in a bundle, group or harness with condition on the number of wires, percent of total harness capacity, etc. This table shows that a 12 gauge wire is necessary for 200 oC operation, 10-gauge for 150 oC and 8-gauge for 105 oC. MIL-W-5088L has various figures showing derating for harnesses as a function of the number of current carrying conductors for different altitudes. MIL-W-5088L only specifies wire for DC or RMS AC conditions, not for transient or overload conditions. MIL-W-5088L and its amendment should be consulted to determine minimum wire sizes for other currents and conditions. 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. The maximum I2t rating for the SPD2P05D28 is 7.45 x 103 Amp2-Seconds. Every wire size in the paragraphs above has an I2t rating that exceeds the SPDP25D28 I2t rating for the temperature rises stated. Therefore, to select a wire size, it’s simply a matter of determining the maximum temperature rise of the application and deciding whether or not the wire will be in a bundle and use the information above. Similarly, the I2t ratings for the SPDP12D28 and SPDP05D28 are 1.72 x 103 Amp2-Seconds and 300 Amp2-Seconds, respectively. ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 9 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 Application Connections The SPDPXXD28 Series may be configured as a high-side or low-side switch and may be used in positive or negative supply applications. Figure 6 – High-Side Switch, Positive Supply Figure 6 shows the connections as a high-side switch with a positive power supply. GAIN GAIN RTN Figure 7 – Low-Side Switch, Positive Supply Figure 7 shows a low-side switch with a negative power supply. Note that the PWRGND pin is now connected to the LINE pin (see Rise/Fall Time paragraph below for more information on the PWRGND pin). ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 10 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 GAIN GAIN RTN Figures 8 and Figure 9 show negative supply high-side switch and low-side switch implementations. Again, note the connection of the PWRGND pin. Figure 8 – High Side Switch, Negative Supply GAIN GAIN RTN Figure 9 – Low Side Switch, Negative Supply ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 11 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 GAIN GAIN RTN Rise Time & Fall Time The rise and fall times of the SPDPXXD28 are pre-set at the factory for a nominal 100μS with a LINE supply of 28VDC (see Table 3 for min/max limits). The rise and fall times will vary linearly with supply voltage. The PWRGND pin is used to control the rise and fall times. If the PWRGND pin is left open, the rise and fall times will be about 50uS. Leaving the PWRGND pin open can be useful when a faster rise or fall time is desirable. With the PWRGND pin connected as in Figures 6 through 9, the SPDPXXD28, when set for a 25 Amp rating, can turn on into a capacitive load of 440uF, min, 880uF, typ, without tripping for any power supply voltage within the ratings. The capacitive load capability is proportional to current rating and can be therefore easily calculated for each model and setting in the SPDPXXD28 Series. Wiring and Load Inductance Wiring inductance can cause voltage transients when the SPDPXXD28 is switched off due to an overload. Generally, these transients are small but must be considered when long wires are used on either the LINE or LOAD pins or both. A 10 foot length of wire in free air will cause a transient voltage of about 10 Volts when the SPDP25D28 trips at an Instant Trip level of 250 Amps. At the rated load current of 25 Amps, the voltage transient will be about 1 Volt. If longer wire lengths are used, a transient suppressor may be used at the LINE pin and a power diode may be used at the LOAD pin so that the total voltage between the LINE and LOAD pins is less than 50 Volts. When powering inductive loads, the negative voltage transient at the LOAD pin can cause the voltage between LINE and LOAD to exceed the SPDPXXD28 rating of 50 Volts and a power diode from the LOAD pin to ground must be used. The cathode of the power diode is connected to the LOAD pin with the anode connected to ground. The power diode must be able to carry the load current when the SPDPXXD28 switches off. Voltage transients due to wiring or load inductance are proportional to the operating current. Paralleling For example, putting two SPDP25D28s in parallel will not double the rating to 50 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 SPDP25D28s in parallel may possibly trip at 35 Amps. Also, both SPDP25D28s will not trip together; the SPDP25D28 carrying the higher current will trip first followed by the other SPDP25D28. Multiple SPDP25D28s may be used in parallel as long as these complexities are appreciated. Due not parallel different models of this series as the current sharing will not be predictable. ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 12 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 Board 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 SPDPXXD28 back on after an overload. The SPDPXXD28 Series 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. MIL-STD-704F and MIL-STD-1275B These standards cover the characteristics of the electrical systems in Military Aircraft and Vehicles. The SPDPXXD28 Series meets all of the requirements of MIL-STD-704F including Normal, Emergency, Abnormal and Electric Starting conditions with the Ripple, Distortion Factor and Distortion Spectrum defined in the standard. The SPDPXXD28 Series also meets all of the requirements of MIL-STD-1275B including operation with Battery and Generator, Generator Only and Battery Only for all of the conditions described in the standard including Cranking, Surges, Spikes and Ripple. In addition, the SPDPXXD28 Series can withstand + 600 V spikes for 10μS. This capability is beyond that required by the standards cited above. Figure 10 – SPDPXXD28 Rating vs. “Gain” and “Gain Return” Terminals 100.00% 90.00% % of Current Rating 80.00% 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% 0.00% 10 100 1000 10000 100000 Proramming Resistor ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 13 SENSITRON SEMICONDUCTOR SPDPXXD28 SERIES TECHNICAL DATA DATASHEET 5023, Rev D.1 ORDERING INFORMATION SPDPXXD28: XX is for maximum amps. For example, SPDP05D28 is programmable from 1A to 5A. 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. ©2007 Sensitron Semiconductor • 221 West Industry Court • Deer Park, NY 11729-4681 Phone (631) 586 7600 Fax (631) 242 9798 • www.sensitron.com • [email protected] • Page 14