SQM48S25010-NS00

TM SemiQ SQM48 Series Data Sheet Family 25A DC-DC Converters The new 25A SemiQ™ Family of DC-DC converters provide a high-efficiency single output in a size that is only 60% of industry-standard quarter-bricks, while preserving the same pinout and functionality. The 25A SQM48 Series converters of the SemiQ™ Family provide thermal performance in high temperature environments that exceeds most competitors' 25 A quarter-bricks. This is accomplished through the use of patent pending circuit, packaging and processing techniques to achieve ultrahigh efficiency, excellent thermal management and a very low body profile. Low body profile and the preclusion of heatsinks minimize airflow shadowing, thus enhancing cooling for downstream devices. The use of 100% automation for assembly, coupled with advanced electric and thermal design, results in a product with extremely high reliability. Operating from a 36-75 V input, the 25A SQM48 Series converters provide any standard output voltage from 2.5 V down to 1.2 V. Outputs can be trimmed from –20% to +10% of the nominal output voltage (±10% for output voltage 1.2 V), thus providing outstanding design flexibility. With a standard pinout and trim equations, the SQM48 Series converters are perfect drop-in replacements for existing 25 A quarter-brick designs. Inclusion of this converter in new designs can result in significant board space and cost savings. The device is also available in a surface mount package. In both cases the designer can expect reliability improvement over other available converters because of the SQM48 Series’ optimized thermal efficiency. Applications  Telecommunications  Data communications  Wireless  Servers SQM48T and SQM48S Converters Features                         MCD10085 Rev. 1.1, 08-Jul-10 Page 1 of 30 RoHS lead-free solder and lead-solder-exempted products are available Delivers up to 25 A (62.5 W) Industry-standard quarter-brick pinout Extremely small footprint: 0.896” x 2.30” (2.06 in2), 40% smaller than conventional quarter-bricks Higher current capability at elevated temperatures than most competitors' 25 A quarter-bricks On-board input differential LC-filter for the lowest input ripple current in industry Outputs available in 2.5, 2.0, 1.8, 1.5, and 1.2 V High efficiency – no heatsink required Start-up into pre-biased output No minimum load required Available in through-hole and SM packages Low profile: 0.28” (7.1 mm) Light weight: 0.66 oz (18.5 g) Meets Basic Insulation requirements of EN60950 Withstands 100 V input transient for 100 ms Fixed-frequency operation Fully protected Remote output sense Output voltage trim range: +10%/−20% with Industrystandard trim equations (except 1.2 V output) High reliability: MTBF of 3.4 million hours, calculated per Telcordia TR-332, Method I Case 1 Positive or negative logic ON/OFF option UL 60950 recognized in US and Canada and DEMKO certified per IEC/EN 60950 (pending) Meets conducted emissions requirements of FCC Class B and EN 55022 Class B with external filter All materials meet UL94, V-0 flammability rating www.power-one.com TM SemiQ SQM48 Series Data Sheet Family 25A DC-DC Converters Electrical Specifications (common to all versions) Conditions: TA=25ºC, Airflow=300 LFM (1.5 m/s), Vin=48 Vdc, All output voltages, unless otherwise specified. PARAMETER ABSOLUTE MAXIMUM RATINGS Input Voltage Operating Ambient Temperature Storage Temperature NOTES Continuous MIN TYP 0 -40 -55 MAX UNITS 80 85 125 Vdc °C °C INPUT CHARACTERISTICS Operating Input Voltage Range Input Under Voltage Lockout Turn-on Threshold Turn-off Threshold Input Voltage Transient 36 48 75 Vdc 33 31 34 32 35 33 100 Vdc Vdc Vdc Non-latching 100 ms ISOLATION CHARACTERISTICS I/O Isolation Isolation Capacitance Isolation Resistance 2000 Vdc pF MΩ 160 10 FEATURE CHARACTERISTICS Switching Frequency 1 Output Voltage Trim Range 435 1 Remote Sense Compensation Output Over-Voltage Protection Over-Temperature Shutdown (PCB) Auto-Restart Period Turn-On Time ON/OFF Control (Positive Logic) Converter Off Converter On ON/OFF Control (Negative Logic) Converter Off Industry-std. equations (2.5 - 1.5 V) Use trim equation on Page 4 (1.2 V) Percent of VOUT(NOM) Non-latching Non-latching Applies to all protection features -20 -10 117 122 125 100 3 +10 +10 +10 127 kHz % % % % °C ms ms -20 2.4 0.8 20 Vdc Vdc 2.4 20 Vdc Additional Notes: 1. Vout can be increased up to 10% via the sense leads or up to 10% via the trim function, however total output voltage trim from all sources should not exceed 10% of VOUT(NOM), in order to insure specified operation of over-voltage protection circuitry. MCD10085 Rev. 1.1, 08-Jul-10 Page 2 of 30 www.power-one.com TM SemiQ SQM48 Series Data Sheet Family 25A DC-DC Converters tion section for system timing waveforms associated with use of the ON/OFF pin. Operation Input and Output Impedance These power converters have been designed to be stable with no external capacitors when used in low inductance input and output circuits. However, in many applications, the inductance associated with the distribution from the power source to the input of the converter can affect the stability of the converter. The addition of a 33 µF electrolytic capacitor with an ESR < 1  across the input helps ensure stability of the converter. 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 20,000 µF on 2.5 – 1.2 V outputs. Remote Sense (Pins 5 and 7) 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). SemiQ Family Rw TM Vin (+) Converter (Top View) Vin ON/OFF Vout (+) 100 SENSE (+) TRIM Rload SENSE (-) 10 ON/OFF (Pin 2) Vin (-) Vout (+) Rw 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 logic and negative logic and both are referenced to Vin(-). Typical connections are shown in Fig. A. SemiQ Family TM Vin (+) Converter (Top View) ON/OFF Vin Vout (+) SENSE (+) TRIM Rload SENSE (-) Vin (-) If remote sensing is not required, 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 value. Because the sense leads carry minimal current, large traces on the end-user board are not required. However, sense traces should be located close to a ground plane to minimize system noise and insure optimum performance. When wiring discretely, twisted pair wires should be used to connect the sense lines to the load to reduce susceptibility to noise. Vout (-) CONTROL INPUT Fig. A: Circuit configuration for ON/OFF function. The positive logic version turns on when the ON/OFF pin is at logic high and turns off when at logic low. The converter is on when the ON/OFF pin is left open. The negative logic version turns on when the pin is at logic low and turns off when the pin is at 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. ON/OFF pin is internally pulled-up to 5 V through a resistor. A 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 0.2 mA at a low level voltage of  0.8 V. An external voltage source of ±20 V max. may be connected directly to the ON/OFF input, in which case it should be capable of sourcing or sinking (depending on the signal polarity) up to 1 mA. See the Start-up Informa- MCD10085 Rev. 1.1, 08-Jul-10 Fig. B: Remote sense circuit configuration. 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, 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 Page 3 of 30 www.power-one.com TM SemiQ actual output power remains at or below the maximum allowable output power. Output Voltage Adjust /TRIM (Pin 6) The output voltage can be adjusted up 10% or down 20% for Vout ≥ 1.5 V, and ±10% for Vout = 1.2 V relative to the rated output voltage by the addition of an externally connected resistor. 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  RTINCR  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 [k] (2.5 – 1.5 V) Δ RTDECR  700  15 [k] (1.2 V) Δ where, RTDECR  Required value of trim-down resistor [k] and Δ is as defined above. Note: The above equations for calculation of trim resistor values match those typically used in conventional industrystandard quarter bricks. 5.11(100  Δ)VONOM  626  10.22 [k] (2.5 –1.5V) 1.225Δ 84.6  7.2 [k] Δ SQM48 Series Data Sheet Family 25A DC-DC Converters SemiQ Family TM Vin (+) Converter (Top View) (1.2 V) Vin ON/OFF Vout (+) SENSE (+) TRIM SENSE (-) Vin (-) where, RTINCR  Required value of trim-up resistor k] VONOM  Nominal value of output voltage [V] 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 previous the section for a complete discussion of this requirement. SemiQ Family TM Converter (Top View) Vin ON/OFF Vout (-) Fig. D: Configuration for decreasing output voltage. (VO-REQ  VO-NOM) Δ X 100 [%] VO -NOM Vin (+) Rload R T-DECR 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 over-voltage 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. Vout (+) SENSE (+) R T-INCR TRIM Rload SENSE (-) Vin (-) Vout (-) Fig. C: Configuration for increasing output voltage. MCD10085 Rev. 1.1, 08-Jul-10 Page 4 of 30 www.power-one.com TM SemiQ SQM48 Series Data Sheet Family 25A DC-DC Converters (pending). Basic Insulation is provided between input and output. Protection Features Input Undervoltage Lockout Input undervoltage lockout is standard with this converter. The converter will shut down when the input voltage drops below a pre-determined voltage. To comply with safety agencies requirements, an input line fuse must be used external to the converter. The Table below provides the recommended fuse rating for use with this family of products. The input voltage must be at least 35 V for the converter to turn on. Once the converter has been turned on, it will shut off when the input voltage drops below 31 V. This feature is beneficial in preventing deep discharging of batteries used in telecom applications. Output Voltage 2.5 V 2.0 - 1.5 V 1.2 V Fuse Rating 4-A 3-A 2.5-A Modules are UL approved for maximum fuse rating of 15-A. To protect a group of modules with a single fuse, the rating can be increased from the recommended values above. Output Overcurrent Protection (OCP) 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. When the output voltage drops below 40-50% of the nominal value of output voltage, the converter will shut down (Fig. x.11). Once the converter has shut down, it will attempt to restart nominally every 100 ms with a typical 1-2% duty cycle (Fig. x.12). The attempted restart will continue indefinitely until the overload or short circuit conditions are removed or the output voltage rises above 40-50% of its nominal value. Output Overvoltage Protection (OVP) 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 100 ms until the OVP condition is removed. Electromagnetic Compatibility (EMC) 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, Power-One tests its converters to several system level standards, primary of which is the more stringent EN55022, Information technology equipment - Radio disturbance characteristics - Limits and methods of measurement. Effective internal LC differential filter significantly reduces input reflected ripple current (Fig. x.9), and improves EMC. With the addition of a simple external filter, all versions of the SQM48 Series of converters pass the requirements of Class B conducted emissions per EN55022 and FCC, and meet at a minimum, Class A radiated emissions per EN 55022 and Class B per FCC Title 47CFR, Part 15-J. Please contact di/dt Applications Engineering for details of this testing. Characterization Overtemperature Protection (OTP) General Information 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. After the converter has cooled to a safe operating temperature, it will automatically restart. The converter has 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, start-up and shutdown parameters, output ripple and noise, transient response to load step-change, overload and short circuit. Safety Requirements The converters meet North American and International safety regulatory requirements per UL60950 and EN60950 MCD10085 Rev. 1.1, 08-Jul-10 The figures are numbered as Fig. x.y, where x indicates the different output voltages, and y associates with specific plots (y = 1 for the vertical thermal derating, …). For example, Fig. x.1 will refer to the vertical thermal derating for all the output voltages in general. Page 5 of 30 www.power-one.com TM SemiQ The following pages contain specific plots or waveforms associated with the converter. Additional comments for specific data are provided below. Test Conditions 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 metalized. The two inner layers, comprising two-ounce copper, were used to provide traces for connectivity to the converter. The lack of metalization 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 vertical and horizontal wind tunnel facilities 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. Power-One recommends the use of AWG #40 gauge thermocouples to ensure measurement accuracy. Careful routing of the thermocouple leads will further minimize measurement error. Refer to Figure H for optimum measuring thermocouple location. SQM48 Series Data Sheet Family 25A DC-DC Converters Efficiency Efficiency vs. load current plot is shown in Fig. x.2 for ambient temperature of 25 ºC, airflow rate of 300 LFM (1.5 m/s), vertical converter mounting, and input voltages of 36 V, 48 V and 72 V. Start-up 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 Fig. x.3 and Fig. x.4, respectively. Ripple and Noise Fig. x.7 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 F ceramic capacitor. The input reflected ripple current waveforms are obtained using the test setup shown in Fig x.8. The corresponding waveforms are shown in Fig. x.9 and Fig. x.10. Thermal Derating Load current vs. ambient temperature and airflow rates are given in Fig. x.1 for through-hole version. Ambient temperature was varied between 25 °C and 85 °C, with airflow rates from 30 to 500 LFM (0.15 to 2.5 m/s), and vertical converter mounting. For each set of conditions, the maximum load current was defined as the lowest of: (i) The output current at which either any FET junction temperature did not exceed a maximum specified temperature (120°C) as indicated by the thermographic image, or (ii) The nominal rating of the converter (25 A on 2.5 – 1.2 V). During normal operation, derating curves with maximum FET temperature less or equal to 120 °C should not be exceeded. Temperature on the PCB at the thermocouple location shown in Fig. H should not exceed 118 °C in order to operate inside the derating curves. MCD10085 Rev. 1.1, 08-Jul-10 Page 6 of 30 www.power-one.com TM SemiQ SQM48 Series Data Sheet Family 25A DC-DC Converters V IN Start-up Information (using negative ON/OFF) Scenario #1: Initial Start-up From Bulk Supply ON/OFF function enabled, converter started via application of VIN. See Figure E. Time Comments t0 ON/OFF pin is ON; system front end power is toggled on, VIN to converter begins to rise. t1 VIN crosses Under-Voltage 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 start-up time (t3- t1) is typically 3 ms. ON/OFF STATE OFF ON V OUT t0 t1 t2 t t3 VIN Scenario #2: Initial Start-up 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). t2 End of converter turn-on delay. t3 Converter VOUT reaches 100% of nominal value. For this example, the total converter start-up time (t3- t1) is typically 3 ms. 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 Comments t0 VIN and VOUT are at nominal values; ON/OFF pin ON. t1 ON/OFF pin arbitrarily disabled; converter output falls to zero; turn-on inhibit delay period (100 ms typical) is initiated, and ON/OFF pin action is internally inhibited. t2 ON/OFF pin is externally re-enabled. If (t2- t1) ≤ 100 ms, external action of ON/OFF pin is locked out by start-up inhibit timer. If (t2- t1) > 100 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) ≤ 100 ms, the total converter start-up time (t5- t2) is typically 103 ms. For (t2- t1) > 100 ms, start-up will be typically 3 ms after release of ON/OFF pin. ON/OFF STATE OFF ON VOUT t0 t1 t 2 t t3 Fig. F: Start-up scenario #2. VIN 100 ms ON/OFF STATE OFF ON VOUT t0 t1 t2 t3 t4 t t5 Fig. G: Start-up scenario #3. Fig. E: Start-up scenario #1. MCD10085 Rev. 1.1, 08-Jul-10 Page 7 of 30 www.power-one.com TM SemiQ SQM48 Series Data Sheet Family 25A DC-DC Converters Electrical Specifications: SQM48T/S25025 (2.5 Volts Out) Conditions: TA=25ºC, Airflow=300 LFM (1.5 m/s), Vin=48 Vdc, Vout=2.5 Vdc unless otherwise specified. PARAMETER INPUT CHARACTERISTICS NOTES Maximum Input Current Input Stand-by Current Input No Load Current (0 load on the output) Input Reflected-Ripple Current Input Voltage Ripple Rejection MIN 25 Adc, 2.5 Vdc Out @ 36 Vdc In Vin = 48 V, converter disabled Vin = 48 V, converter enabled 25MHz bandwidth 120Hz TYP MAX UNITS 2.0 Adc mAdc mAdc mAPK-PK dB 2.500 2.525 Vdc ±2 ±2 ±5 ±5 2.538 50 20,000 25 32 46 6.7 mV mV Vdc mVPK-PK μF Adc Adc A Arms 3 37 6 TBD OUTPUT CHARACTERISTICS Output Voltage Set Point (no load) Output Regulation Over Line Over Load Output Voltage Range Output Ripple and Noise - 25MHz bandwidth External Load Capacitance Output Current Range Current Limit Inception Peak Short-Circuit Current RMS Short-Circuit Current -40ºC to 85ºC 2.475 Over line, load and temperature Full load + 10 μF tantalum + 1 μF ceramic Plus full load (resistive) 2.462 30 0 26.5 Non-latching Non-latching. Short=10mΩ. Non-latching 30 35 DYNAMIC RESPONSE Load Change 20% of Iout Max, di/dt = 0.1 A/μS di/dt = 5 A/μS Setting Time to 1% Co = 1 μF ceramic Co = 450 μF tant. + 1 μF ceramic 80 140 100 mV mV µs 85.5 89 % % EFFICIENCY 30 0.95 25 0.90 20 0.85 Efficiency Load Current [Adc] 100% Load 50% Load 15 500 LFM (2.5 m/s) 400 LFM (2.0 m/s) 300 LFM (1.5 m/s) 200 LFM (1.0 m/s) 100 LFM (0.5 m/s) 30 LFM (0.15 m/s) 10 5 0.80 0.75 72 V 48 V 36 V 0.70 0 0.65 20 30 40 50 60 70 80 90 0 Ambient Temperature [°C] 10 15 20 25 30 Load Current [Adc] Fig. 2.5V.1: Available load current vs. ambient air temperature and airflow rates for SQM48T25025 converter with D height pins mounted vertically with air flowing from pin 3 to pin 1, MOSFET temperature  120 C, Vin = 48 V. MCD10085 Rev. 1.1, 08-Jul-10 5 Fig. 2.5V.2: Efficiency vs. load current and input voltage for SQM48T/S25025 converter mounted vertically with air flowing from pin 3 to pin 1 at a rate of 300 LFM (1.5 m/s) and Ta = 25 C. Page 8 of 30 www.power-one.com TM SemiQ SQM48 Series Data Sheet Family 25A DC-DC Converters SQM48T/S25025 (2.5 Volts Out) Fig. 2.5V.3: Turn-on transient at full rated load current (resistive) with no output capacitor at Vin = 48 V, triggered via ON/OFF pin. Top trace: ON/OFF signal (5 V/div.). Bottom trace: output voltage (1 V/div.). Time scale: 1 ms/div. Fig. 2.5V.4: Turn-on transient at full rated load current (resistive) plus 20,000 F at Vin = 48 V, triggered via ON/OFF pin. Top trace: ON/OFF signal (5 V/div.). Bottom trace: output voltage (1 V/div.). Time scale: 2 ms/div. Fig. 2.5V.5: Output voltage response to load current stepchange (5 A – 10 A – 5 A) at Vin = 48 V. Top trace: output voltage (100 mV/div.). Bottom trace: load current (5 A/div.). Current slew rate: 0.1 A/s. Co = 1 F ceramic. Time scale: 0.2 ms/div. Fig. 2.5V.6: Output voltage response to load current stepchange (5 A – 10 A – 5 A) at Vin = 48 V. Top trace: output voltage (100 mV/div.). Bottom trace: load current (5 A/div.). Current slew rate: 5 A/s. Co = 450 F tantalum + 1 F ceramic. Time scale: 0.2 ms/div. MCD10085 Rev. 1.1, 08-Jul-10 Page 9 of 30 www.power-one.com TM SemiQ SQM48 Series Data Sheet Family 25A DC-DC Converters SQM48T/S25025 (2.5 Volts Out) is 10 H source inductance Vsource ic 33 F ESR