APPLICATION NOTES WALL INDUSTRIES, INC. B Q S E R I E S Model No. BQ48S2.5-50 Technical Specifications All specifications are based on 25C, Nominal Line and Full Load unless otherwise noted. We reserve the right to change specifications based on technological advances. SPECIFICATION Related condition MIN INPUT Turn on at Turn off at Input Over voltage Shutdown Turn off at Turn on at Operating Voltage Range Maximum Input Current No Load Input Current Input Current under “LOGIC OFF” Inrush Current Transient Rating Reflected Ripple Current OUTPUT Output Voltage Set point Output Voltage Regulation Over Load Over Line Over Temperature Output Voltage Ripple and Noise Basic Ripple Spikes P-P Output Current Ranges Output Current Limit Short Term Output Current Surge DYNAMIC CHARACTERISTICS Input Voltage Ripple Rejection Output Transient and Load Changes Load step / delta V Load step / delta V Recovery Time Turn on Delay Overshoot of Output Voltage EFFICIENCY @ 100% load @ 75% load @ 50% load @ 25% load TEMPERATURE CONSIDERATIONS Thermal Resistance Normal Convection 100 lfm 200 lfm 300 lfm 400 lfm Heatsink Considerations General Technical Data Switching Frequency Remote ON OFF Control Trimmablility Over Temperature Shutdown MTBF Rated Input Voltage Low Line 100% load 2.475 Rated Output Current 0 24 MAX Unit Measured 34 32 Volt DC Volt DC n/a n/a 48 1.69 50 2 1 50 Volt DC Volt DC Volt DC A mA mA A2 Sec mA 2.500 28 75 2.525 Volt DC 0.1 0.1 0.02 % % % / oC 150 20 32 mV mV A A A/sec 120 Hz 60 dB 50 to 75% 50 to 100% 75 to 50% 100 to 50 % To within 1% Rated Vo From Vin(nom) to 90% Vout (nom) Full Load Resistive 100 100 100 0 mV mV µsec M sec % 83 86 86 83 % % % % X X Rtheta c-a 35 10.2 8.0 5.4 4.4 3.4 o C/Watt C/Watt o C/Watt o C/Watt o C/Watt o Contact Factory Fixed Positive or Negative 370 Case Temperature 105 Bellcore TR-332 nom is 2.35M (888) 597-WALL 36 NOM www.wallindustries.com KHz High/Low TTL o C Hours 1 APPLICATION NOTES WALL INDUSTRIES, INC. B Q S E R I E S %RATEDOUTPUTPOWER DERATING CURVE 100 90 80 70 60 50 40 30 20 10 0 NATURAL CONVECTION 100 LFM 200 LFM 300 LFM 400 LFM 5 15 25 35 45 55 65 75 85 95 105 0 AMBIENT TEMPERATURE C BQ48S2.5-50 POWERDISSIPATION(Watts) POWER DISSIPATION VS OUTPUT POWER 20 18 16 14 12 10 8 6 4 2 0 36 VIN 48 VIN 75VIN 0 10 20 30 40 50 60 70 80 90 100 % OUTPUT POWER BQ48S2.5-50 EFFICIENCY(%) EFFICIENCY VS RATED OUTPUT POWER 90 85 80 75 70 65 60 55 50 45 40 36V 48V 75V 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 10 0 RATED OUTPUT POWER (%) BQ48S2.5-50 (888) 597-WALL www.wallindustries.com 2 APPLICATION NOTES WALL INDUSTRIES, INC. TYPICAL OUTPUT RIPPLE VOLTAGE 50mV/div, 2 us/div, full load 48 vin 10 uF decoupling cap. Room temperature. B Q S E R I E S TYPICAL INPUT REFLECTED RIPPLE CURRENT 10mA/div, full load 48 vin.(using 12uH, 33uF (low ESR) source impedance). Room temperature. TYPICAL RISE TIME AND TURN ON DELAY USING LOGIC ENABLE 1 V/div, 10 mS/div, (vout) 2 V/div, 10 mS/div (logic enable) 48 vin, full load. Room temperature. TYPICAL RISE TIME AND TURN ON DELAY WITH VIN 0-48V 1V/div, 10 mS/div, (vout) 20 V/div 10 mS/div (vin) 48 vin full load. Room temperature. BQ48S2.5-50AR (888) 597-WALL www.wallindustries.com 3 Wall Industries, Inc. BQ Series Application Notes BQ Series Trim Function The following information is provided to allow quick calculation of the trim resistor value for a desired output voltage. The general procedure for calculating a trim resistor is as follows: 1. Determine the desired output voltage change. (∆%). 2. Select Equation. (Trim Low/Trim High) 3. Evaluate. * If no voltage trim is required, the trim pin may be left floating (unconnected). In order to trim low use Equation 1 to calculate resistor RTL (external) for the desired output voltage. Equation 1: Trim Low RTL = [(510/∆%)-10.2]KΩ Basic Schematic : Trim Low In order to trim high use Equation 2 and Table 1 to calculate resistor RTH (external) for the desired output voltage. Equation 2: Trim High RTH=[(5.1Vo(100+∆%)/1.225∆%)-(510/∆%)-10.2]KΩ Vo = Nominal output voltage. Basic Schematic : Trim High Wall Industries, Inc. 5 Watson Brook Road Exeter, NH 03833 (888) 597-9255 (603) 778 2300 www.wallindustries.com