Technical Reference Notes (TRN) REV Description PR-A Preliminary Release PR-B Preliminary Release PR-C Remove 1.5, 2, 5V unit – misc. BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Date 4/30/00 9/05/00 3/28/01 Approved KTF updates TECHNICAL REFERENCE NOTES (TRN) BK60C-H SERIES HIGH EFFICIENCY DC-DC CONVERTER ASTEC POWER ANDOVER, MA _____________________________________________________________ ASTEC POWER - Andover 1 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Electrical Specifications Absolute Maximum Ratings Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are absolute stress ratings only. Functional operation of the device in not implied at these or any other conditions in excess of those given in the operational sections of the TRN. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability. Table 1. Absolute Maximum Ratings Parameter Device Input Voltage: Continuous: All Transient (100ms) All Operating Case Temperature All Storage Temperature All Operating Humidity All I/O Isolation All Symbol Min Typ Max Unit VI VI, trans Tc Tstg - 0 0 -40 -55 - - 80 100 100 125 95 1500 Vdc Vdc ºC ºC % Vdc Device All 018FX 025FX 033FX All Symbol VI II,max II,max II,max II Min 36 - Typ 48 10 Max 75 3.0 4.0 5.0 - Unit Vdc A A A mAp-p All - - - 7.5 W All - - - 3.7 uF Typ 1.8 2.5 3.3 Max 1.83 2.54 3.35 Unit Vdc Vdc Vdc Input Specifications Table 2. Input Specifications Parameter Operating Input Voltage Maximum Input Current (VI = 0 to VI,max: Io = Io,max) Input Reflected-ripple Current (5Hz to 20MHz: 12uH source impedance: TA = 25 ºC.) See Figure 9. No Load Input Power (VI = VI,nom ) Internal Input Capacitance Output Specifications Table 3. Output Specifications Parameter Output Voltage Setpoint (VI = VI,min to VI,max: Io = Io,max; TA = 25 ºC ) Device 018FX 025FX 033FX Symbol Vo,set Vo,set Vo,set Min 1.77 2.46 3.25 _____________________________________________________________ ASTEC POWER - Andover 2 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Output Specifications (continued) Table 3. Output Specifications (continued) Parameter Output Regulation: Line (VI = VI,min to VI,max) Device Symbol Min Typ Max Unit All - - 0.05 0.1 15 - 0.2 0.3 50 150 %Vo %Vo mV mVp-p 0.5 0.5 0.5 45 - 10,000 uF 018FX 025FX 033FX All Io Io Io Io 40 40 40 55 A A A A All - - - 190 %Io,max 018FX 025FX 033FX 018FX 025FX 033FX Io Io Io f f f 80 82 84 - 82 84 86 330 330 400 - % % % kHz kHz kHz All - - - 6 300 %Vo usec All - - - 6 300 %Vo usec All - - 2 5 msec All - - - 5 %Vo Load(Io = Io,min to Io,max) Temperature (Tc = -40 ºC to +100 ºC) Output Ripple and Noise All (Across 0.1uF ceramic and 10uF tantalum capacitors) See Figure 10. External Load Capacitance Output Current Output Current-limit Inception All (Vo = 90% Vo,set) Output Short-circuit Current (Vo = 250mV) Efficiency (VI = VI,nom ; Io = Io,max; Tc = 25°C) Switching Frequency Dynamic Response: (∆Io/∆t = 1A/10us; VI = VI,nom ; Tc = 70 ºC ) Load Change from Io = 50% to 75% of Io, max: Peak Deviation Settling Time Load Change from Io = 50% to 25% of Io, max: Peak Deviation Settling Time Turn-on Time (Io = Io,max; Vo within 1%) Output Voltage Overshoot (Io = Io,max; Tc = 70 ºC) _____________________________________________________________ ASTEC POWER - Andover 3 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Isolation Specifications Table 4. Isolation Specifications Parameter Isolation Capacitance Isolation Resistance Device All All Symbol - Min - Typ 2300 1000 Max - Unit pF Mohm Device All Symbol - Min - Typ TBD Max - Unit hours All - - - 100(3.5) g (oz.) Device Symbol Min Typ Max Unit All Ion/off - - 1.0 mA All All Von/off Von/off -0.7 - - 1.2 10 V V All Ion/off - - 50 uA All Von/off - - 1.2 V All All - 90 - 0.5 110 V %Vo General Specifications Table 5. General Specifications Parameter Calculated MTBF (Io = Io,max; TA = 25 ºC) Weight Feature Specifications Table 6. Feature Specifications Parameter Remote On/Off Signal Interface: (VI = 0 to VI,max ; Open collector or equivalent compatible; Signal referenced to VI (-) terminal.) Positive Logic – No Suffix Low Logic – Module Off High Logic – Module On Negative Logic –Suffix “N” Low Logic – Module On High Logic – Module Off Module Specifications: On/Off Current – Logic Low On/Off Voltage: Logic Low Logic High (Ion/off = 0) Open Collector Switch Specifications: Leakage Current – Logic High (Von/off = 10V) Output Voltage – Logic Low (Ion/off = 1mA) Output Voltage Adjustment Remote Sense Range Voltage Adjustment Range _____________________________________________________________ ASTEC POWER - Andover 4 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Feature Specifications (continued) Table 6. Feature Specifications (continued) Parameter Output Overvoltage Clamp Overtemperature Shutdown Undervoltage Lockout Turn-on Point Turn-off Point Device 018FX 025FX 033FX All Symbol Vo,clamp Vo,clamp Vo,clamp Tc Min 2.4 3.1 3.9 105 Typ 110 Max 2.7 3.5 4.6 120 Unit V V V ºC All All - 32 34.5 32.5 35 - V V _____________________________________________________________ ASTEC POWER - Andover 5 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Characteristic Curves BK60C-048L-033F40H Input Current (Worst Case) Tc = 25 C, Iout = 40A 6 5 4 3 2 1 0 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 Vin (Volts) Figure 1. Typical Input Current vs Input Voltage. Vin = 36Vdc Vin = 48Vdc Vin = 75Vdc BK60C-048L-018F40H Efficiency vs Output Current Tc = 25 Deg Celsius Vin = 36Vdc Vin = 48Vdc Vin = 75Vdc BK60C-048L-025F40H Efficiency vs Output Current Tc = 25 Deg Celsius 95% 95% 90% 90% 85% 85% 80% 80% 75% 75% 70% 70% 65% 65% 60% 60% 55% 55% 50% 50% 0 5 10 15 20 25 Output Current (Amps) 30 35 40 Figure 2. 018F Efficiency vs Load Current. 0 5 10 15 20 25 Output Current (Amps) 30 Figure 3. 025F Efficiency vs Load Current. Vin = 36 Vdc Vin = 48 Vdc Vin = 75 Vdc BK60C-048L-033F40H Efficiency vs Output Current Tc = 25 Deg Celsius 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 0 5 10 15 20 25 Output Current (Amps) 30 35 40 Figure 4. 033F Efficiency vs Load Current. _____________________________________________________________ ASTEC POWER - Andover 6 of 14 35 40 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Characteristic Curves (continued) Figure 5. Typical Output Voltage Startup Vi = Vi,nom, Io = Io,max. Figure 6. Typical Output Ripple (033F) Vi = Vi,nom, Io = Io,max. Figure 7. Typical Dynamic Response (033F) Step Load Change from 50% to 75% Io,max Figure 8. Typical Dynamic Response (033F) Step Load Change from 50% to 25% Io,max _____________________________________________________________ ASTEC POWER - Andover 7 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Test Configurations TO OSCILLOSCOPE Vi(+) Ltest 12 uH Cs 220 uF ESR < 0.1 OHM @ 20 ºC, 100 kHz BATTERY 33 uF ESR < 0.7 OHM @ 20 ºC, 100 kHz Vi(-) Note: Measure input reflected-ripple current with a simulated source inductance (Ltest) of 12 uH. Capacitor Cs offsets possible battery impedance. Measure current as shown above. Figure 9. Input Reflected-ripple Test Setup. COPPER STRIP Vo(+) 0.1 uF 10 uF SCOPE RESISTIVE LOAD Vo(-) Note: Use a 0.1 uF ceramic capacitor and a 10 uF tantalum capacitor. Scope measurement should be made using a BNC socket. Position the load between 51 mm and 76 mm (2 in. and 3 in. ) from module. Figure 10. Peak-to-Peak Output Noise Measurement Test Setup. _____________________________________________________________ ASTEC POWER - Andover 8 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Feature Descriptions Output Overvoltage Clamp The output overvoltage clamp consists of a separate control loop, independent of the primary control loop. This control loop has a higher voltage setpoint than the primary loop. In a fault condition the converter goes into “Hiccup Mode”, and the output overvoltage clamp ensures that the output voltage does not exceed Vo,clamp,max. This secondary control loop provides a redundant voltage-control that reduces the risk of output overvoltage. Output Current Protection To provide protection in an output overload or short circuit condition, the converter is equipped with current limiting circuitry and can endure the fault condition for an unlimited duration. At the point of current-limit inception, the converter goes into “Hiccup Mode”, causing the output current to be limited both in peak and duration. The converter operates normally once the output current is brought back into its specified range. Enable (Optional) Two enable option are available. Positive Logic Enable, no suffix, and Negative Logic Enable, suffix “N”. Positive Logic Enable turns the converter on during a logic-high voltage on the enable pin, and off during a logic-low. Negative Logic Enable turns the converter off during a logic-high and on during a logic-low. Output Voltage Adjustment Output voltage adjustment is accomplished by connecting an external resistor between the Vadj Pin and either the +Sense or –Sense Pins. With an external resistor between the Vadj Pin and -Sense Pin (Radj-down) the output voltage set point (Vo,adj) decreases (see Figure 11). The following equation determines the required external resistor value to obtain an adjusted output voltage: Radj_down 100 2 . kohm %Vo, adj Where Radj-down is the resistance value and %Vo,adj is the percent change in the output voltage. With an external resistor between the Vadj Pin and +Sense Pin (Radj-up) the output voltage set point (Vo,adj) increases (see Figure 12). The following equation determines the required external resistor value to obtain an adjusted output voltage: Radj_up Vo. ( 100 %Vo , adj ) 1.225. %Vo , adj 100 2. %Vo, adj . kohm %Vo, adj Where Radj-up is the resistance value and %Vo,adj is the percent change in the output voltage. _____________________________________________________________ ASTEC POWER - Andover 9 of 14 Technical Reference Notes (TRN) -Vin Case BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W -Vout -Sense Radj-down Vadj Enable +Vin Rload +Sense +Vout Figure 11 . Circuit Configuration to Decrease Output Voltage. -Vin Case -Vout -Sense Rload Vadj Radj-up Enable +Vin +Sense +Vout Figure 12 . Circuit Configuration to Increase Output Voltage. _____________________________________________________________ ASTEC POWER - Andover 10 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Thermal Considerations The power converter operates in a variety of thermal environments: however, sufficient cooling should be provided to help ensure reliable operation of the converter. Heat-dissipating components are thermally coupled to the case. Heat is removed by conduction, convection and radiation to the surrounding environment. Proper cooling can be verified by measuring the case temperature. Heat Transfer Characteristics Increasing airflow over the converter enhances the heat transfer via convection. Figure 13 shows the maximum power that can be dissipated by the converter without exceeding the maximum case temperature versus local ambient temperature (TA) for natural convection through 2.0 m/s (400 ft/min). Systems in which these converters are used generate airflow rates of 0.25 m/s (50 ft/min) due to other heat dissipating components in the system. Therefore, the natural convection condition represents airflow rates of approximately 0.25 m/s (50 ft/min). Use of Figure 13 is shown in the following example. Example What is the minimum airflow required for an 033F40H operating at 48 V, an output current of 25 A, and maximum ambient temperature of 55 ºC. Solution: Given: Vi = 48 V, Io = 25 A, TA = 55 ºC. Determine PD (Figure 16): PD = 13 W. Determine airflow (Figure 16): v = 1.0 m/s (200 ft/min) Nat. Conv. BK60C SERIES Power Derating Curve 0.5 m/s (100 ft/min) 1.0 m/s (200 ft/min) 2.0 m/s (400 ft/min) 30 25 20 15 10 5 0 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 Ambient Temperature (ºC) Figure 13. Forced Convection Power Derating _____________________________________________________________ ASTEC POWER - Andover 11 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Thermal Considerations (continued) BK60C-048L-018F40H Dissipation vs Output Current Tc = 100 Deg Celsius BK60C-048L-025F40H Dissipation vs Output Current Tc = 100 Deg Celsius Vin = 36 Vdc Vin = 48 Vdc Vin = 75 Vdc 25 25 20 20 15 15 10 10 5 5 0 Vin = 36 Vdc Vin = 48 Vdc Vin = 75 Vdc 0 0 5 10 15 20 25 Output Current (Amps) 30 35 40 Figure 14. 018F Pwr. Diss. vs Load Current. 0 5 10 15 20 25 Output Current (Amps) 30 Figure 15. 025F Pwr. Diss. vs Load Current. Vin = 36 Vdc Vin = 48 Vdc Vin = 75 Vdc BK60C-048L-033F40H Dissipation vs Output Current Tc = 100 Deg Celsius 30 25 20 15 10 5 0 0 5 10 15 20 25 Output Current (Amps) 30 35 40 Figure 16. 033F Pwr. Diss. vs Load Current. _____________________________________________________________ ASTEC POWER - Andover 12 of 14 35 40 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Outline Drawing Tolerances: x.xx +/- 0.02 in (x.x +/- 0.5mm) x.xxx +/- 0.010 in (x.xx +/- 0.25mm Pin Assignment 1. 2. 3. 4. 5. 6. 7. 8. 9. -Vin Case Enable (on/off) + Vin - Output - Sense Trim + Sense + Output All pins are 0.040 diameter except pins 5 & 9 which are 0.080 diameter. _____________________________________________________________ ASTEC POWER - Andover 13 of 14 Technical Reference Notes (TRN) BK60C-H Series 36 Vdc to 75 Vdc Inputs, 150 W Table 8 Part Numbers. Model Designation 018FN 025FN 033FN 018F 025F 033F Part Number BK60C-048L-018F40HN BK60C-048L-025F40HN BK60C-048L-033F40HN BK60C-048L-018F40H BK60C-048L-025F40H BK60C-048L-033F40H Table 9. Options Suffix N No Suffix -6 -8 Option Negative Logic Enable Positive Logic Enable 3.7 mm Pin Length 2.8 mm Pin Length _____________________________________________________________ ASTEC POWER - Andover 14 of 14