SSQE48T25012-NAA0G

The new SSQE48T25012 DC-DC converter is an open frame sixteenth-brick DC-DC converter that conforms to the Distributed Open Standards Architecture (DOSA) specifications. The converter operates over an input voltage range of 36 to 75 VDC, and provides a tightly regulated output voltage with an output current up to 25 A. The output is fully isolated from the input and the converter meets Basic Insulation requirements permitting a positive or negative output configuration. The converter is constructed using a single-board approach with both planar and discrete magnetics. The standard feature set includes remote On/Off (positive or negative logic), input undervoltage lockout, output overvoltage, overcurrent, and short circuit protections, output voltage trim, and overtemperature shutdown with hysteresis. With standard pinout and trim equations and excellent thermal performance, the SSQE48T25012 converters can replace in most cases existing eighth-brick converters. Inclusion of this converter in a new design can result in significant board space and cost savings. • • • • • • • • • • • • • • • • • • • • • • 36-75 VDC Input Industry-standard DOSA pinout Output: 1.2 V @ 25 A; 30 W On-board input differential LC-filter Start-up into pre-biased load No minimum load required Weight: 0.44 oz [12.3 g] Meets Basic Insulation requirements of EN 62368-1 Withstands 100 V input transient for 100 ms Fixed-frequency operation Hiccup overcurrent protection Fully protected (OTP, OCP, OVP, UVLO) Remote sense Remote ON/OFF positive or negative logic option Output voltage trim range: +10%/−20% with industry-standard trim equations Low height of 0.374” (9.5 mm) Industry standard 1/16th brick footprint: 0.9” by 1.3” High reliability: MTBF = 16.23 million hours, calculated per Telcordia TR-332, Method I Case 1 Designed to meet Class B conducted emissions per FCC and EN 55032 when used with external filter All materials meet UL94, V-0 flammability rating Approved to the latest edition and amendment of ITE Safety standards, UL/CSA 62368-1 and IEC 62368-1 RoHS lead free solder and lead-solder-exempted products are available SSQE48T25012 2 Conditions: TA = 25ºC, Airflow = 300 LFM (1.5 m/s), Vin = 48 VDC, Cin = 33 µF, unless otherwise specified. PARAMETER CONDITIONS /DESCRIPTION MIN TYP MAX UNITS Absolute Maximum Ratings Input Voltage 0 80 VDC Operating Ambient Temperature Continuous -40 85 °C Storage Temperature -55 125 °C Isolation Characteristics I/O Isolation 2250 Isolation Capacitance VDC 150 Isolation Resistance pF 10 MΩ Feature Characteristics Switching Frequency 411 1 Output Voltage Trim Range Industry-standard equations (1.2 V) Remote Sense Compensation1 Percent of VOUT (NOM) Output Over-voltage Protection2 Non-latching Over-temperature Shutdown (PCB) Auto-Restart Period Non-latching Sinking current from external voltage source equal VOUT(NOM) – 0.6V and connected to output via 1Ohm resistor Converter OFF external voltage = 5 VDC Applies to all protection features Turn-On Time See Figures E, F, and G Peak Backdrive Output Current during startup into prebiased output Backdrive Output Current in OFF state ON/OFF Control (Positive Logic) ON/OFF Control (Negative Logic) 440 -20 120 130 469 kHz +10 % +10 % 140 125 % °C 50 mADC 10 mADC 200 ms 5 ms Converter Off (logic low) -20 0.8 VDC Converter On (logic high) 2.4 20 VDC Converter Off (logic high) 2.4 20 VDC Converter On (logic low) -20 0.8 VDC Mechanical Weight 12.3 g Reliability Telcordia SR-332, Method I Case 1 50% electrical stress, 40°C ambient MTBF 16.23 MHrs Input Characteristics Operating Input Voltage Range Input Under-voltage Lockout 36 48 75 VDC Turn-on Threshold 33 34 35 VDC Turn-off Threshold 31 32 33 VDC Input Voltage Transient 100ms 100 VDC Maximum Input Current VIN = 36 VDC , IOUT = 25 ADC 1.1 ADC Input Stand-by Current Input No Load Current (0 load on the output) Input Reflected-Ripple Current, is Vin = 48V, converter disabled 10 mA Vin = 48V, converter enabled 23 mA Vin = 48V, 25 MHz bandwidth 10 mAPK-PK Input Voltage Ripple Rejection 120Hz 60 dB 1 Vout can be increased up to 10% via the sense leads or 10% via the trim function. However, the total output voltage trim from all sources shall not exceed 10% of VOUT(NOM) in order to ensure specified operation of overvoltage protection circuitry. 2 Output Over-voltage Protection for SSQE48T25012-NABSG will be 180% to 200% of VOUT Nominal. tech.support@psbel.com SSQE48T25012 3 Output Characteristics External Load Capacitance Plus full resistive load Output Current Range 1.2 VDC Current Limit Inception Non-latching, for 1.2 VDC Peak Short-Circuit Current Non-latching, Short = 10 mΩ RMS Short-Circuit Current Non-latching Output Voltage Setpoint Accuracy (no load) Output Regulation Overall Output Voltage Regulation Output Ripple and Noise – 25 MHz bandwidth 0 27.5 30,000 µF 25 ADC 35 ADC 35 A 8.75 Arms +1.5 %VOUT Over Line -1.5 ±2 ±5 mV Over Load ±2 ±5 mV +3.0 %Vout 70 mVPK-PK Over line, load and temperature3 -3.0 Full load + 10µF tantalum + 1µF ceramic 35 Co = 1µF ceramic + 10 µF tantalum Figure 8 30 mV 40 µs 120 mV 40 µs Dynamic Response Load Change 50%-75%-50% of Iout Max, di/dt = 0.1 A/μs Settling Time to 1% of Vout Load Change 50%-75%-50% of Iout Max, di/dt = 5 A/μs Settling Time to 1% of Vout Co = 470 µF POS + 1µF ceramic Figure 9 Efficiency 100% Load VOUT = 1.2 VDC 83 % 50% Load VOUT = 1.2 VDC 85.5 % These power converters have been designed to be stable with no external capacitors when used in low inductance input and output circuits. However, in some applications, the inductance associated with the distribution from the power source to the input of the converter can affect the stability of the converter. A 33 µF electrolytic capacitor with an ESR < 1Ω across the input is recommended to ensure stability of the converter over the wide range of input source impedance. In many applications, the user has to use decoupling capacitance at the load. The power converter will exhibit stable operation with external load capacitance up to 30,000 µF. The ON/OFF pin is used to turn the power converter on or off remotely via a system signal. There are two remote control options available, positive and negative logic, both referenced to Vin(-). A typical connection is shown in Fig. A. Vin (+) SSQE48 Converter (Top View) ON/OFF Vin Vout (+) SENSE (+) TRIM Rload SENSE (-) Vin (-) Vout (-) CONTROL INPUT Figure A. Circuit configuration for ON/OFF function. 3 Operating ambient temperature range is -40ºC to 85ºC Asia-Pacific +86 755 298 85888 Europe, Middle East +353 61 49 8941 North America +1 866 513 2839 © 2023 Bel Fuse Inc. BCD.00648_AC SSQE48T25012 4 The positive logic version turns on when the ON/OFF pin is at a logic high and turns off when the pin is at a logic low. The converter is on when the ON/OFF pin is left open. See the Electrical Specifications for logic high/low definitions. The negative logic version turns on when the pin is at a logic low and turns off when the pin is at a logic high. The ON/OFF pin can be hard wired directly to Vin(-) to enable automatic power up of the converter without the need of an external control signal. The ON/OFF pin is internally pulled up to 5 V through a resistor. A properly de-bounced mechanical switch, open-collector transistor, or FET can be used to drive the input of the ON/OFF pin. The device must be capable of sinking up to 0.2mA at a low level voltage of  0.8V. An external voltage source (±20V maximum) may be connected directly to the ON/OFF input, in which case it must be capable of sourcing or sinking up to 1mA depending on the signal polarity. See the Startup Information section for system timing waveforms associated with use of the ON/OFF pin. The remote sense feature of the converter compensates for voltage drops occurring between the output pins of the converter and the load. The SENSE(-) (Pin 5) and SENSE(+) (Pin 7) pins should be connected at the load or at the point where regulation is required (see Fig. B). SSQE48 Converter Vin (+) (Top View) Rw Vout (+) 100 SENSE (+) ON/OFF Vin TRIM Rload SENSE (-) 10 Vin (-) Vout (-) Rw Figure B. Remote sense circuit configuration. CAUTION If remote sensing is not utilized, the SENSE(-) pin must be connected to the Vout(-) pin (Pin 4), and the SENSE(+) pin must be connected to the Vout(+) pin (Pin 8) to ensure the converter will regulate at the specified output voltage. If these connections are not made, the converter will deliver an output voltage that is slightly higher than the specified data sheet value. Because the sense leads carry minimal current, large traces on the end-user board are not required. However, sense traces should be run side by side and located close to a ground plane to minimize system noise and ensure optimum performance. The converter’s output overvoltage protection (OVP) senses the voltage across Vout(+) and Vout(-), and not across the sense lines, so the resistance (and resulting voltage drop) between the output pins of the converter and the load should be minimized to prevent unwanted triggering of the OVP. When utilizing the remote sense feature, care must be taken not to exceed the maximum allowable output power capability of the converter, which is equal to the product of the nominal output voltage and the allowable output current for the given conditions. When using remote sense, the output voltage at the converter can be increased by as much as 10% above the nominal rating in order to maintain the required voltage across the load. Therefore, the designer must, if necessary, decrease the maximum current (originally obtained from the derating curves) by the same percentage to ensure the converter’s actual output power remains at or below the maximum allowable output power. The output voltage can be adjusted up 10% or down 20%. The TRIM pin should be left open if trimming is not being used. To minimize noise pickup, a 0.1 µF capacitor is connected internally between the TRIM and SENSE(-) pins. To increase the output voltage, refer to Fig. C. A trim resistor, RT-INCR, should be connected between the TRIM (Pin 6) and SENSE(+) (Pin 7), with a value of: RT−INCR = 5.11 (100 + Δ)  VO−NOM 511 − - 10.22 0.6Δ Δ , [kΩ], where, RT−INCR = Required value of trim-up resistor [kΩ] VO−NOM = Nominal value of output voltage [V] tech.support@psbel.com SSQE48T25012 5 Δ= (VO -REQ − VO -NOM ) X 100 VO -NOM , [%] VO−REQ = Desired (trimmed) output voltage [V]. When trimming up, care must be taken not to exceed the converter‘s maximum allowable output power. See the previous section for a complete discussion of this requirement. Vin (+) SSQE48 Converter Vout (+) (Top View) SENSE (+) Vin ON/OFF R T-INCR TRIM Rload SENSE (-) Vin (-) Vout (-) Figure C. Configuration for increasing output voltage. To decrease the output voltage (Fig. D), a trim resistor, RT-DECR, should be connected between the TRIM (Pin 6) and SENSE(-) (Pin 5), with a value of: RT−DECR = 511 − 10.22 |Δ| , [kΩ] where, RT-DECR = Required value of trim-down resistor [kΩ] and Δ is defined above. NOTE: The above equations for calculation of trim resistor values match those typically used in conventional industry-standard quarterbricks, eighth-bricks and sixteenth-bricks. Vin (+) SSQE48 Converter Vout (+) (Top View) SENSE (+) Vin ON/OFF TRIM Rload RT-DECR SENSE (-) Vin (-) Vout (-) Figure D. Configuration for decreasing output voltage. Trimming/sensing beyond 110% of the rated output voltage is not an acceptable design practice, as this condition could cause unwanted triggering of the output overvoltage protection (OVP) circuit. The designer should ensure that the difference between the voltages across the converter’s output pins and its sense pins does not exceed 10% of VOUT (nom), or: [VOUT(+) − VOUT(−)] − [VSENSE(+) − VSENSE(−)]  VO - NOM X 10% [V] This equation is applicable for any condition of output sensing and/or output trim. Asia-Pacific +86 755 298 85888 Europe, Middle East +353 61 49 8941 North America +1 866 513 2839 © 2023 Bel Fuse Inc. BCD.00648_AC 6 SSQE48T25012 Input undervoltage lockout is standard with this converter. The converter will shut down when the input voltage drops below a pre-determined voltage. The input voltage must be typically 34 V for the converter to turn on. Once the converter has been turned on, it will shut off when the input voltage drops typically below 32 V. This feature is beneficial in preventing deep discharging of batteries used in telecom applications. The converter is protected against overcurrent or short circuit conditions. Upon sensing an overcurrent condition, the converter will switch to constant current operation and thereby begin to reduce output voltage. During short circuit, when the output voltage drops below 50% its nominal value, the converter will shut down. Once the converter has shut down, it will attempt to restart nominally every 200ms with a very low duty cycle. The attempted restart will continue indefinitely until the overload or short circuit conditions are removed. Once the output current is brought back into its specified range, the converter automatically exits the hiccup mode and continues normal operation. The converter will shut down if the output voltage across Vout(+) (Pin 8) and Vout(-) (Pin 4) exceeds the threshold of the OVP circuitry. The OVP circuitry contains its own reference, independent of the output voltage regulation loop. Once the converter has shut down, it will attempt to restart every 200 ms until the OVP condition is removed. The converter will shut down under an overtemperature condition to protect itself from overheating caused by operation outside the thermal derating curves, or operation in abnormal conditions such as system fan failure. Converter will automatically restart after it has cooled to a safe operating temperature. The converters are safety approved to UL/CSA 62368-1 and IEC/EN 62368-1. Basic Insulation is provided between input and output. The converters have no internal fuse. If required, the external fuse needs to be provided to protect the converter from catastrophic failure. Refer to the “Input Fuse Selection for DC/DC converters” application note at belfuse.com/powersolutions for proper selection of the input fuse. Both input traces and the chassis ground trace (if applicable) must be capable of conducting a current of 1.5 times the value of the fuse without opening. The fuse must not be placed in the grounded input line. Abnormal and component failure tests were conducted with the input protected by an external UL-listed fuse, rated 20A. If a fuse rated greater than 20A is used, additional testing may be required. To protect a group of converters with a single fuse, the rating can be increased from the recommended value above. EMC requirements must be met at the end-product system level, as no specific standards dedicated to EMC characteristics of board mounted component DC-DC converters exist. However, Bel Power Solutions tests its converters to several system level standards, primary of which is the more stringent EN 55032, Information technology equipment - Radio disturbance characteristics-Limits and methods of measurement. An effective internal LC differential filter significantly reduces input reflected ripple current, and improves EMC. With the addition of a simple external filter, all versions of the SSQE48T25012 converters pass the requirements of Class B conducted emissions per EN 55032 and FCC requirements. Please contact Bel Power Solutions Applications Engineering for details of this testing. tech.support@psbel.com SSQE48T25012 7 VIN Scenario #1: Initial Startup From Bulk Supply ON/OFF function enabled, converter started via application of VIN. See Figure E. Time t0 Comments ON/OFF pin is ON; system front-end power is toggled on, VIN to converter begins to rise. t1 VIN crosses undervoltage Lockout protection circuit threshold; converter enabled. t2 Converter begins to respond to turn-on command (converter turn-on delay). t3 Converter VOUT reaches 100% of nominal value. For this example, the total converter startup time (t3- t1) is typically 5 ms. ON/OFF STATE OFF ON VOUT t0 t1 t2 t t3 Figure E. Startup scenario #1. VIN Scenario #2: Initial Startup Using ON/OFF Pin With VIN previously powered, converter started via ON/OFF pin. See Figure F. Time Comments t0 VINPUT at nominal value. t1 Arbitrary time when ON/OFF pin is enabled (converter enabled). End of converter turn-on delay. Converter VOUT reaches 100% of nominal value. t2 t3 ON/OFF STATE OFF ON For this example, the total converter startup time (t3- t1) is typically 5 ms. VOUT t0 t1 t2 t t3 Figure F. Startup scenario #2. V IN Scenario #3: Turn-off and Restart Using ON/OFF Pin With VIN previously powered, converter is disabled and then enabled via ON/OFF pin. See Figure G. Time t0 t1 Comments VIN and VOUT are at nominal values; ON/OFF pin ON. ON/OFF pin arbitrarily disabled; converter output falls to zero; turn-on inhibit delay period (200 ms typical) is initiated, and ON/OFF pin action is internally inhibited. t2 ON/OFF pin is externally re-enabled. If (t2- t1) ≤ 200 ms, external action of ON/OFF pin is locked out by startup inhibit timer. If (t2- t1) > 200 ms, ON/OFF pin action is internally enabled. t3 Turn-on inhibit delay period ends. If ON/OFF pin is ON, converter begins turn-on; if off, converter awaits ON/OFF pin ON signal; see Figure F. t4 End of converter turn-on delay. t5 Converter VOUT reaches 100% of nominal value. For the condition, (t2- t1) ≤ 200 ms, the total converter startup time (t5- t2) is typically 204 ms. For (t2- t1) > 200 ms, startup will be typically5 ms after release of ON/OFF pin. 200 ms ON/OFF STATE OFF ON V OUT t0 Asia-Pacific +86 755 298 85888 t1 t2 t3 t4 t5 t Figure G. Startup scenario #3. Europe, Middle East +353 61 49 8941 North America +1 866 513 2839 © 2023 Bel Fuse Inc. BCD.00648_AC SSQE48T25012 8 The converters have been characterized for many operational aspects, to include thermal derating (maximum load current as a function of ambient temperature and airflow) for vertical and horizontal mounting, efficiency, startup and shutdown parameters, output ripple and noise, transient response to load step-change, overload, and short circuit. All data presented were taken with the converter soldered to a test board, specifically a 0.060” thick printed wiring board (PWB) with four layers. The top and bottom layers were not metallized. The two inner layers, comprised of two-ounce copper, were used to provide traces for connectivity to the converter. The lack of metallization on the outer layers as well as the limited thermal connection ensured that heat transfer from the converter to the PWB was minimized. This provides a worst-case but consistent scenario for thermal derating purposes. All measurements requiring airflow were made in the vertical and horizontal wind tunnel using Infrared (IR) thermography and thermocouples for thermometry. Ensuring components on the converter do not exceed their ratings is important to maintaining high reliability. If one anticipates operating the converter at or close to the maximum loads specified in the derating curves, it is prudent to check actual operating temperatures in the application. Thermographic imaging is preferable; if this capability is not available, then thermocouples may be used. The use of AWG #40 gauge thermocouples is recommended to ensure measurement accuracy. Careful routing of the thermocouple leads will further minimize measurement error. Refer to Fig. H for the recommended measuring thermocouple location. Fig. H: Location of the thermocouple for thermal testing. Load current vs. ambient temperature and airflow rates are given in Figure 1. Ambient temperature was varied between 25°C and 85°C, with airflow rates from 30 to 500 LFM (0.15 to 2.5m/s). For each set of conditions, the maximum load current was defined as the lowest of: (i) The output current at which any FET junction temperature does not exceed a maximum specified temperature of 125°C as indicated by the thermographic image, or (ii) The temperature of the transformer does not exceed 125°C, or (iii) The nominal rating of the converter. During normal operation, derating curves with maximum FET temperature less or equal to 125°C should not be exceeded. Temperature at thermocouple locations TC1 and TC2 shown in Fig. H should not exceed 100°C and 125°C respectively, in order to operate inside the derating curves. Figure 2 shows the efficiency vs. load current plot for ambient temperature of 25ºC, airflow rate of 300 LFM (1.5 m/s) with vertical mounting and input voltages of 36V, 48V, and 72V. Also, a plot of efficiency vs. load current, as a function of ambient temperature with Vin=48V, airflow rate of 200 LFM (1 m/s) with vertical mounting is shown in Figure 3. tech.support@psbel.com SSQE48T25012 9 Figure 4 shows the power dissipation vs. load current plot for Ta = 25ºC, airflow rate of 300 LFM (1.5 m/s) with vertical mounting and input voltages of 36 V, 48 V, and 72 V. Also, a plot of power dissipation vs. load current, as a function of ambient temperature with Vin = 48 V, airflow rate of 200 LFM (1 m/s) with vertical mounting is shown in Figure 5. Output voltage waveforms during the turn-on transient using the ON/OFF pin for full rated load currents (resistive load) are shown without and with external load capacitance in Figure 6 and Figure 7, respectively. 30 90 25 85 20 80 Efficiency, % Load Current, A Figure 10 shows the output voltage ripple waveform, measured at full rated load current with a 10 µF tantalum and 1 µF ceramic capacitor across the output. Note that all output voltage waveforms are measured across a 1 µF ceramic capacitor. The input reflected-ripple current waveforms are obtained using the test setup shown in Figure 11. 15 10 65 30 40 72V 60 0 20 36V 70 48V NC ~ 30 LFM (0.15 m/s) 100 LFM (0.5 m/s) 200 LFM (1 m/s) 300 LFM (1.5 m/s) 400 LFM (2 m/s) 500 LFM (2.5 m/s) 5 75 50 60 70 80 90 0 5 Ambient Temperature, C Figure 1. Available load current vs. ambient air temperature and airflow rates for SSQE48T25012 converter mounted vertically with air flowing from pin 1 to pin 3, Vin = 48 V. Note: NC – Natural convection 10 15 Load Current, A 20 25 Figure 2. Efficiency vs. load current and input voltage for SSQE48T25012 converter mounted vertically with air flowing from pin 1 to pin 3 at a rate of 300 LFM (1.5 m/s) and Ta=25C. 90 8 Power Dissipation, W Efficiency, % 85 80 40C 55C 70C 75 6 4 36V 2 48V 72V 85C 0 70 0 0 5 10 15 Load Current, A 20 25 Figure 3. Efficiency vs. load current and ambient temperature for SSQE48T25012 converter mounted vertically with Vin = 48 V and air flowing from pin 1 to pin 3 at a rate of 200LFM (1.0m/s). 5 10 15 Load Current, A 20 25 Figure 4. Power dissipation vs. load current and input voltage for SSQE48T25012 converter mounted vertically with air flowing from pin 1 to pin 3 at a rate of 300 LFM (1.5 m/s) and Ta = 25C. Asia-Pacific +86 755 298 85888 Europe, Middle East +353 61 49 8941 North America +1 866 513 2839 © 2023 Bel Fuse Inc. BCD.00648_AC SSQE48T25012 10 Power Dissipation, W 8 6 4 40C 55C 70C 85C 2 0 0 5 10 15 Load Current, A 20 25 Figure 5. Power dissipation vs. load current and ambient temperature for SSQE48T25012 converter mounted vertically with Vin = 48 V and air flowing from pin 1 to pin 3at a rate of 200 LFM (1.0 m/s). Figure 6. Turn-on transient at full rated load current (resistive) with Co=1µF cer+10µF tant at Vin = 48 V, triggered via ON/OFF pin. Top trace: ON/OFF signal (5 V/div.). Bottom trace: Output voltage (0.5 V/div.). Time scale: 5 ms/div. Figure 7. Turn-on transient at full rated load current (resistive) plus 30,000 µF at Vin = 48 V, triggered via ON/OFF pin. Top trace: ON/OFF signal (5 V/div.). Bottom trace: Output voltage (0.5 V/div.). Time scale: 5 ms/div. Figure 8. Output voltage response to load current step-change (12.5A–18.75A–12.5A) at Vin=48V. Top trace: output voltage (100mV/div.). Bottom trace: load current (10A/div.). Current slew rate: 0.1A/µs. Co=1µF cer+10µF tant. Time scale: 0.2ms/div. Figure 9. Output voltage response to load current step-change (12.5A–18.75A–12.5A) at Vin=48V. Top trace: output voltage (100 mV/div.). Bottom trace: load current (10A/div.). Current Figure 10. Output voltage ripple (20 mV/div.) at full rated load current into a resistive load with Co = 10µF tantalum + 1µF slew rate: 5A/µs. Co=470µF POS+1µF cer. ceramic and Vin = 48V. Time scale: 1µs/div. Time scale: 0.2ms/div. tech.support@psbel.com SSQE48T25012 11 iS 10 H source inductance Vsource iC 33 F ESR < 1  electrolytic capacitor SSQE48 DC-DC Converter 1 F Ceramic + 10 F Vout Tantalum Capacitor Figure 11. Test setup for measuring input reflected ripple currents, ic and is. Figure 12. Input reflected-ripple current, iS (10 mA/div.), measured through 10 µH at the source at full rated load current and Vin = 48V. Refer to Figure 11 for test setup. Time scale: 1 µs/div. Figure 14. Output voltage vs. load current showing current limit point and converter shutdown point. Input voltage has almost no effect on current limit characteristic. Figure 13. Input reflected ripple-current, iC (200 mA/div.), measured at input terminals at full rated load current and Vin = 48 V. Refer to Figure 11 for test setup. Time scale: 1 µs/div. Figure 15. Load current (top trace, 20 A/div., 50 ms/div.) into a 10 m short circuit during restart, at Vin = 48 V. Bottom trace (10 A/div., 5 ms/div.) is an expansion of the on-time portion of the top trace Asia-Pacific +86 755 298 85888 Europe, Middle East +353 61 49 8941 North America +1 866 513 2839 © 2023 Bel Fuse Inc. BCD.00648_AC SSQE48T25012 12 PAD / PIN CONNECTIONS Pad/Pin # Function 1.300±0.020 [33.02±0.51] 0.100 [2.54] 0.150 [3.81] 1.100 [27.94] 0.600 [15.24] 0.150 [3.81] 4X Vin (+) 2 3 ON/OFF Vin (-) 4 Vout (-) 5 6 SENSE(-) TRIM 7 8 SENSE(+) Vout (+) 0.900±0.020 [22.86±0.51] 0.300 [7.62] 2X SSQE48T Pinout (Through-hole) SSQE48T Platform Notes • • • • • • 1 All dimensions are in inches [mm] Pins 1-3 and 5-7 are Ø 0.040” [1.02] with Ø 0.078” [1.98] shoulder Pins 4 and 8 are Ø 0.062” [1.57] without shoulder Pin material: Brass Pin Finish: Matte Tin over Nickel Converter Weight: 0.44 oz [12.3 g] PRODUCT SERIES INPUT VOLTAGE MOUNTING SCHEME RATED CURRENT OUTPUT VOLTAGE SSQE 48 T 25 012 - Height Option A Pin Option PL Pin Length ±0.005 [±0.13] A B 0.188 [4.78] 0.145 [3.68] C 0.110 [2.79] HT (Max. Height) +0.000 [+0.00] -0.038 [- 0.97] 0.374 [9.5] ON/OFF LOGIC MAXIMUM HEIGHT [HT] PIN LENGTH [PL] N A B CL (Min. Clearance) +0.016 [+0.41] -0.000 [- 0.00] 0.027 [0.7] SPECIAL FEATURES RoHS 0 G 0  No special features Sixteenth Brick Format 36-75 V T Throughhole 25  25 ADC 012  1.2 V N Negative P Positive Through hole A⇒ 0.374” A  0.188” B  0.145” C  0.110” N  Sink current during start-up is limited to 50 mA S  Modules per Nokia/Alcatel specification. Pass the surge test at their end. No Suffix  RoHS lead-solderexemption compliant G  RoHS compliant for all six substances The example above describes P/N SSQE48T25012-NAB0G: 36-75 V input, through-hole, 25A @ 1.2V output, negative enable (ON/OFF logic), pin length of 0.145”, maximum height of 0.374”, standard feature set, and RoHS compliant for all 6 substances. Consult factory for availability of other options. NUCLEAR AND MEDICAL APPLICATIONS - Products are not designed or intended for use as critical components in life support systems, equipment used in hazardous environments, or nuclear control systems. TECHNICAL REVISIONS - The appearance of products, including safety agency certifications pictured on labels, may change depending on the date manufactured. Specifications are subject to change without notice. tech.support@psbel.com