1000 WATT FXP SERIES DC/DC CONVERTERS Features Description The 4:1 Input Voltage 1000 Watt Single FXP DC/DC converter provides a regulated dc output with capability for paralleling up to three converters delivering up to 2.8kW. Current sharing among converters is achieved using droop method and does not require a current share pin. The output voltage is fully isolated from the input, allowing the output to be positive or negative polarity and with various ground connections. The 1000 Watt FXP meets the most rigorous performance standards in an industry standard footprint for mobile (12Vin), process control (24Vin), and military COTS (28Vin) applications. The 4:1 Input Voltage 1000W FXP includes trim and remote ON/OFF. Threaded through holes are provided to allow easy mounting or addition of a heatsink for extended temperature operation. The converters high efficiency and high power density are accomplished through use of high-efficiency synchronous rectification technology, advanced electronic circuit, packaging and thermal design thus resulting in a high reliability product. Converter operates at a fixed frequency and follows conservative component de-rating guidelines. 4:1 Input voltage range High power density Parallel Operation - up to 3 units (2.8kW) Small size 2.5" x 4.7" x 0.52" Efficiency up to 96% Excellent thermal performance with metal case Over-Current and Short Circuit Protection Over-Temperature protection Auto-restart Monotonic startup into pre bias Constant frequency Remote ON/OFF Good shock and vibration damping Temperature Range -40C to +105C Available. RoHS Compliant Input Range VDC Model Vout VDC Iout ADC Min Max 24S24.42FXP (ROHS) 9 36 24 42 24S28.36FXP (ROHS) 9 36 28 36 24S48.21FXP (ROHS) 9 36 48 21 24S53.19FXP (ROHS) 9 36 53 19 1. Negative Logic ON/OFF feature available. Add "-N" to the part number when ordering. i.e. 24S24.42FXP-N (ROHS) 2. Designed to meet MIL-STD-810G for functional shock and vibration. The unit must be properly secured to the interface medium (PCB/Chassis) by use of the threaded inserts of the unit. 3. A thermal management device, such as a heatsink, is required to ensure proper operation of this device. The thermal management medium is required to maintain baseplate < 105C for full rated power. 4. Non-Standard output voltages are available. Please contact the factory for additional information. Product is designed and manufactured in the USA. 2401 Stanwell Drive, Concord Ca. 94520 Fax: 925-687-3333 Ph: 925-687-4411 Page 1 of 22 www.calex.com Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS Electrical Specifications Conditions: TA = 25 C, Airflow = 300 LFM (1.5 m/s), Vin = 24VDC, unless otherwise specified. Specifications are subject to change without notice. All Models Parameter Notes Min Typ Max Units 40 50 V V -40 105 C -55 125 C Absolute Maximum Ratings Input Voltage Continuous 0 Transient (100ms) Operating Temperature Baseplate (100% load) Storage Temperature Isolation Characteristics and Safety Isolation Voltage Input to Output 2250 V Input to Baseplate & Output to Baseplate 1500 V Isolation Capacitance Isolation Resistance 9000 pF 20 M 10 Insulation Safety Rating Basic Designed to meet UL/cUL 60950, IEC/EN 60950-1 Feature Characteristics Fixed Switching Frequency 200 Input Current and Output Voltage Ripple Output Voltage Trim Range Adjustable via TRIM (Pin 12) Remote Sense Compensation Between SENSE+ and +OUT pins Output Overvoltage Protection Non-latching 114 Overtemperature Shutdown (Baseplate) Non-latching (Vin=9V; 12V, 24/36V) 108 Auto-Restart Period Applies to all protection features Time from UVLO to Vo=90%VOUT(NOM) Resistive load 1.7 Turn-On Delay Time from Vin Turn-On Delay Time from ON/OFF Control (From ON to 90%VOUT(NOM) Resistive load) Rise Time (Vout from 10% to90%) kHz kHz 400 110 % 1 V 122 130 % 112 115 C 2 2.3 s 480 517 530 ms 24S24.42FXP & 24S28.36FXP 20 27 35 ms 24S48.21FXP & 24S53.19FXP 20 35 50 24S24.42FXP & 24S28.36FXP 4 7 11 ms ms 24S48.21FXP & 24S53.19FXP 7 15 25 ms Pin open = ON or 2 60 ON/OFF Control - Positive Logic ON state Control Current Leakage current OFF state Control current Sinking 12 V 0.16 mA 0 0.8 V 0.3 0.36 mA ON/OFF Control - Negative Logic ON state Pin shorted to - ON/OFF pin or 0 0.8 V OFF state Pin open = OFF or 2 12 V Thermal Characteristics Thermal resistance Baseplate to Ambient 2401 Stanwell Drive, Concord Ca. 94520 Converter soldered to 5" x 3.5" x 0.07", 3.3 4 layers/ 2Oz copper FR4 PCB. Ph: 925-687-4411 Fax: 925-687-3333 Page 2 of 22 www.calex.com C/W Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS Electrical Specifications (Continued): Conditions: TA = 25 C, Airflow = 300 LFM (1.5 m/s), Vin = 24VDC, unless otherwise specified. Specifications are subject to change without notice. 24S24.42FXP Parameter Notes Min Typ Max 9 24 36 V 8.2 8.5 8.8 V 7.7 8.0 0.55 8.3 V Units Input Characteristics Operating Input Voltage Range Input Under Voltage Lockout Turn-on Threshold Non-latching Turn-off Threshold Lockout Hysteresis Voltage 0.4 Maximum Input Current Vin = 9V, 80% Load Vin = 12V, 100% Load A A 92 Input Stand-by Current Converter Disabled Input Current @ No Load Converter Enabled 330 Minimum Input Capacitance (external)1) ESR < 0.1 1000 mARMS 3 4 mA 420 500 mA 0.19 F 2 A s Inrush Transient Input Terminal Ripple Current, iC V 89 350 Vin = 24V, Output Shorted 2) 0.7 ARMS 1.6 20 MHz bandwidth, 100% Load (Fig.24) Output Characteristics Output Voltage Range Over Load, Line and temperature 23.549 24.301 V Output Voltage Set Point Accuracy (No load) 24.179 24.240 24.301 V Output Regulation Over Line Vin = 9V to 36V Over Load Vin = 24V, Load 0% to 100% 2.37 Temperature Coefficient External Load Capacitance1), 2) Output Current Range (See Fig. A) Current Limit Inception RMS Short-Circuit Current 0.10 % 2.5 2.63 % 0.005 0.015 %/C 27.4 Overvoltage Protection Output Ripple and Noise 20 MHz bandwidth 0.05 See Fig. 6 and Table 1 for details. Full load, 20 MHz bandwidth. 31.2 V 60 120 mVPK-PK 15 35 mVRMS 1000 4700 F 10 100 m Vin = 12V - 36V 0 42 A Vin = 9V 0 33.6 A Full Load (resistive) (over operating temp range) CEXT ESR Vin = 12V - 36V 46.2 50.2 54.6 A 9V Vin < 12V 37 49 54.6 A 2.7 5 ARMS Non-latching, Continuous 2) Dynamic Response Load Change 50%-75%-50%, di/dt = 1A/s See Fig. 21 and Table 1 for CEXT. 560 800 mVP-P Load Change 50%-100%-50%, di/dt = 1A/s See Fig 22 and Table 1 for CEXT. 1100 1600 mVP-P 700 Settling Time to 1% of VOUT s Efficiency 100% Load 50% Load Vin = 24V 93.6 94.6 95.3 % Vin = 12V 92.4 93.4 94.1 % Vin = 24V 94.8 95.6 96.4 % Vin = 12V 94.7 95.4 96.3 % 1) Section "Input and Output Capacitance" and Table 1 (Section "Test Configuration")" 2) See Section "Test Configuration" for details. Output voltage deviation is measured peak to peak (includes switching ripple and voltage droop). 2401 Stanwell Drive, Concord Ca. 94520 Ph: 925-687-4411 Fax: 925-687-3333 Page 3 of 22 www.calex.com Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS Electrical Specifications (Continued): Conditions: TA = 25 C, Airflow = 300 LFM (1.5 m/s), Vin = 24VDC, unless otherwise specified. Specifications are subject to change without notice. 24S28.36FXP Notes Parameter Min Typ Max Units 9 24 36 V Turn-on Threshold 8.2 8.5 8.8 V Turn-off Threshold 7.7 8.3 V Lockout Hysteresis Voltage 0.4 8.0 0.55 0.7 V Vin = 9V, 80% Load 89 A Vin = 12V, 100% Load 92 A Operating Input Voltage Range Input Under Voltage Lockout Non-latching Maximum Input Current 330 Vin = 24V, Output Shorted Input Stand-by Current Converter Disabled Input Current @ No Load Converter Enabled 400 ESR < 0.1 1000 1) Minimum Input Capacitance (external) mARMS 3 4 mA 460 560 mA 0.19 F 2 A s ARMS Inrush Transient Input Reflected Ripple Current, iC 2) 20 MHz bandwidth, 100% Load (Fig. 26) 1.3 Output Characteristics Nominal Output Voltage Over Load, Line and temperature 27.463 Output Voltage Set Point Accuracy (No load) 28.205 28.347 V 28.347 V 0.05 0.1 % 2.5 0.005 2.63 0.015 %/C 28.276 Output Regulation Over Line Over Load Vin = 9V to 36V Vin = 24V, Load 0% to 100% 2.37 Temperature Coefficient 31.9 Overvoltage Protection Output Ripple and Noise 50 See Fig. 6 and Table 1 for details. Full load 20 MHz bandwidth. 12 CEXT ESR % 36.4 V 100 mVPK-PK 25 mVRMS 1000 4700 F 10 100 m 0 36 A External Load Capacitance1),2) Full Load (resistive) (over operating temp range) Output Current Range (See Fig. A) Vin = 12V - 36V 0 28.8 A Current Limit Inception Vin = 12V - 36V 39.6 46.8 A 9V Vin < 12V 31.7 Vin = 9V 46.8 A Non-latching 1.8 2.5 ARMS Load Change 50%-75%-50%, di/dt = 1A/s See Fig. 27 and Table 1 for CEXT. 500 720 mV Load Change 50%-100%-50%, di/dt = 1A/s See Fig. 28 and Table 1 for CEXT. 1000 1500 mV RMS Short-Circuit Current Dynamic Response 700 Settling Time to 1% of VOUT s Efficiency 100% Load 50% Load 1) 2) 94.8 Vin = 24V 95.6 96.3 % Vin = 12V 93.0 93.8 94.5 % Vin = 24V 95.6 96.4 97.1 % Vin = 12V 94.3 95.4 96.2 % Section "Input and Output Capacitance" and Table 1 (Section "Test Configuration") See Section "Test Configuration" for details. Output voltage deviation is measured peak to peak (includes switching ripple and voltage droop). 2401 Stanwell Drive, Concord Ca. 94520 Ph: 925-687-4411 Fax: 925-687-3333 Page 4 of 22 www.calex.com Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS Electrical Specifications (Continued): Conditions: TA = 25 C, Airflow = 300 LFM (1.5 m/s), Vin = 24VDC, unless otherwise specified. Specifications are subject to change without notice. 24S48.21FXP Parameter Notes Min Typ Max 9 24 36 V Units Input Characteristics Operating Input Voltage Range Input Under Voltage Lockout Turn-on Threshold Non-latching 8.2 8.5 8.8 V Turn-off Threshold 7.7 8.3 V Lockout Hysteresis Voltage 0.4 8.0 0.55 0.7 V Vin = 9V, 80% Load 89 A Vin = 12V, 100% Load 92 A Maximum Input Current 350 Vin = 24V, Output Shorted Input Stand-by Current Converter Disabled Input Current @ No Load Converter Enabled 360 Minimum Input Capacitance (external)1) ESR < 0.1 1000 4 mA 460 550 mA 0.19 F 2 A s Inrush Transient Input Terminal Ripple Current, iC2) mARMS 3 ARMS 1.6 20 MHz bandwidth, 100% Load (Fig. 36) Output Characteristics Output Voltage Range Over Load, Line and temperature 47.086 48.601 V Output Voltage Set Point Accuracy (No load) 48.359 48.480 48.601 V Output Regulation Over Line Vin = 9V to 36V Over Load Vin = 24V, Load 0% to 100% 2.37 Temperature Coefficient 0.05 0.10 2.5 2.63 % 0.005 0.015 %/C 54.7 Overvoltage Protection See Fig. 6 and Table 1 for details. Full load 20 MHz bandwidth. Output Ripple and Noise CEXT ESR % 62.4 V 100 240 mVPK-PK 30 80 mVRMS 470 3000 F m External Load Capacitance Full Load (resistive) (over operating temp range) 10 100 Output Current Range (See Fig. A) Vin = 12V - 36V 0 21 A Vin = 9V 0 16.8 A 1), 2) Current Limit Inception RMS Short-Circuit Current Vin = 12V - 36V 23.1 25.2 9V Vin < 12V 18.5 24.2 27.3 27.3 A 1.4 2.4 ARMS Non-latching, Continuous A 2) Dynamic Response Load Change 50%-75%-50%, di/dt = 1A/s See Fig. 33. 660 950 mVP-P Load Change 50%-100%-50%, di/dt = 1A/s See Fig. 34. 1320 1900 mVP-P 600 Settling Time to 1% of VOUT s Efficiency 100% Load 50% Load 1) 2) Vin = 24V 94.3 95 95.7 % Vin = 12V 93.2 93.9 94.6 % Vin = 24V 95.3 96 96.7 % Vin = 12V 95.1 95.8 96.5 % Section "Input and Output Capacitance" and Table 1 (Section "Test Configuration") See Section "Test Configuration" for details. Output voltage deviation is measured peak to peak (includes switching ripple and voltage droop). 2401 Stanwell Drive, Concord Ca. 94520 Ph: 925-687-4411 Fax: 925-687-3333 Page 5 of 22 www.calex.com Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS Electrical Specifications (Continued): Conditions: TA = 25 C, Airflow = 300 LFM (1.5 m/s), Vin = 24VDC, unless otherwise specified. Specifications are subject to change without notice. 24S53.19FXP Notes Parameter Min Typ Max Units 9 24 36 V Turn-on Threshold 8.2 8.5 8.8 V Turn-off Threshold 7.7 8.3 V Lockout Hysteresis Voltage 0.4 8.0 0.55 0.7 V Vin = 9V, 80% Load 89 A Vin = 12V, 100% Load 92 A Operating Input Voltage Range Input Under Voltage Lockout Non-latching Maximum Input Current 330 Vin = 24V, Output Shorted Input Stand-by Current Converter Disabled Input Current @ No Load Converter Enabled 400 ESR < 0.1 1000 1) Minimum Input Capacitance (external) mARMS 2 4 mA 460 560 mA 0.19 F 2 A s ARMS 53.664 V 53.664 V 0.05 0.1 % 2.5 0.005 2.63 0.015 %/C Inrush Transient Input Reflected-Ripple Current, iC 1.2 25 MHz bandwidth, 100% Load (Fig. 6) Output Characteristics Nominal Output Voltage Over Load, Line and temperature 51.991 Output Voltage Set Point Accuracy (No load) 53.396 53.530 Output Regulation Over Line Over Load Vin = 9V to 36V Vin = 24V, Load 0% to 100% 2.37 Temperature Coefficient 60.4 Overvoltage Protection Output Ripple and Noise External Load Capacitance1) Output Current Range (See Fig. A) Current Limit Inception RMS Short-Circuit Current 100 See Fig. 6 and Table 1 for details. Full load 20 MHz bandwidth Full Load (resistive) (over operating temp range) 30 CEXT ESR % 68.9 V 240 mVPK-PK 80 mVRMS 470 2200 F 10 100 m Vin = 12V - 36V 0 19 A Vin = 9V 0 15.2 A Vin = 12V - 36V 20.9 22.8 24.7 A 9V Vin < 12V 16.7 20 24.7 1 2 A ARMS Non-latching Dynamic Response2) Load Change 50%-75%-50%, di/dt = 1A/s Load Change 50%-100%-50%, di/dt = 1A/s See Fig. 39. 550 800 mVP-P See Fig. 40. 1100 1600 mVP-P mV s 600 Settling Time to 1% of VOUT Efficiency 100% Load 50% Load 1) 2) Vin = 24V 94.7 95.5 96.2 % Vin = 12V 93.3 94 94.8 % Vin = 24V 95.5 96.2 97 % Vin = 12V 94.8 95.5 96.2 % Section "Input and Output Capacitance" and Table 1 (Section "Test Configuration"). See Section "Test Configuration" for details. Output voltage deviation is measured peak to peak (includes switching ripple and voltage droop). 2401 Stanwell Drive, Concord Ca. 94520 Ph: 925-687-4411 Fax: 925-687-3333 Page 6 of 22 www.calex.com Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS Environmental and Mechanical Specifications. Specifications are subject to change without notice. Parameter Note Min Max Typ Units Environmental Operating Humidity Non-condensing 95 % Storage Humidity Non-condensing 95 % 1 ROHS Compliance See Calex Website http://www.calex.com/RoHS.html for the complete RoHS Compliance statement Shock and Vibration Designed to meet MIL-STD-810G for functional shock and vibration. Water washability Not recommended for water wash process. Contact the factory for more information. Mechanical Weight Pins 3, 3A, 4, 4A, 5, 6, 8 and 9 Through Hole Pins Diameter Pins 1, 2, 10, 11 and 12 Through Hole Pins Material Through Hole Pin Finish 8.55 Ounces 242 Grams 0.079 0.081 0.083 Inches 2.006 2.057 2.108 mm 0.038 0.04 0.042 Inches 0.965 1.016 1.667 mm Pins 3, 3A, 4, 4A, 5, 6 , 8 and 9 C14500 or C1100 Copper Alloy Pins 1, 2, 10, 11 and 12 Brass Alloy TB3 or "Eco Brass" All pins 10" Gold over nickel Case Dimension 4.7 x 2.5 x 0.52 Inches 119.38 x 63.50 x 13.21 mm Plastic: Vectra LCP FIT30: 1/2-16 EDM Finish Case Material Aluminum Material Baseplate Flatness 0.010 Inches 0.25 mm Reliability Telcordia SR-332, Method I Case 1 50% electrical stress, 40C components MTBF MHrs 5.4 EMI and Regulatory Compliance Conducted Emissions 1 MIL-STD 461F CE102 with external EMI filter network (See Figs. 39-41) Additional Notes: The RoHS marking is as follows \ Output Power vs. Input Voltage Output Power [W] 1200 1000 800 600 400 200 0 9 12 15 18 21 24 27 30 33 36 Input Voltage [V] Figure A: Output Power as function of input voltage. 2401 Stanwell Drive, Concord Ca. 94520 Ph: 925-687-4411 Fax: 925-687-3333 Page 7 of 22 www.calex.com Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS Operations When converter is started by applying the input voltage with ON/OFF pin active there is delay of 500msec that was intentionally provided to prevent potential startup issues especially at low input voltages Input Fusing The FXP converters do not provide internal fusing and therefore in some applications external input fuse may be required. Use of external fuse is also recommended if there is possibility for input voltage reversal. For greatest safety, it is recommended to use fast blow fuse in the ungrounded input supply line. Input Reverse Polarity Protection The FXP converters do not have input reverse polarity. If input voltage polarity is reversed, internal diodes will become forward biased and draw excessive current from the power source. If the power source is not current limited or input fuse not used, the converter could be permanently damaged. Input Undervoltage Protection Input undervoltage lockout is standard with this converter. The FXP converter will start and regulate properly if the ramping-up input voltage exceeds Turn-on threshold of typ. 8.5V (See Specification) and remains at or above Turn-on Threshold. The converter will turn off when the input voltage drops below the Turn-off Threshold of typical 8V (See specification) and converter enters hiccup mode and will stay off for 2 seconds. The converter will restart after 2 seconds only if the input voltage is again above the Turn-on Threshold. The built-in hysteresis and 2 second hiccup time prevents any unstable on/off operation at the low input voltage near Turn-on Threshold. User should take into account for IR and inductive voltage drop in the input source and input power lines and make sure that the input voltage to the converter is always above the Turn-off Threshold voltage under ALL OPERATING CONDITIONS. Because of the switching nature and negative input impedance of DC/DC converters, the input of these converters must be driven from the source with both low AC impedance and DC input regulation. The FXP converters are designed to operate without external components as long as the source voltage has very low impedance and reasonable voltage regulation. However, since this is not the case in most applications an additional input capacitor is required to provide proper operations of the FXP converter. Specified values for input capacitor are recommendation and need to be adjusted for particular application. Due to large variation between applications some experimentation may be needed. In many applications, the inductance associated with the distribution from the power source to the input of the converter can affect the stability and in some cases, if excessive, even inhibit operation of the converter. This becomes of great consideration for input voltage at 12V or below. The DC input regulation, associated with resistance between input power source and input of the converter, plays significant role in particular in low input voltage applications such as 12V battery systems. Note that input voltage at the input pins of the connector must never degrade below Turn-off threshold under all load operating conditions. Note that in applications with high pulsating loads additional input as well as output capacitors may be needed. In addition, for EMI conducted measurement, due to low input voltage it is recommended to use 5H LISNs instead of typical 50H LISNs. Input/ Output Filtering Input Capacitor Start-Up Time The start-up time is specified under two different scenarios: a) Startup by ON/OFF remote control (with the input voltage above the Turn-on Threshold voltage) and b) Start-up by applying the input voltage (with the converter enabled via ON/OFF remote control). The startup times are measured with maximum resistive load as: a) the interval between the point when the ramping input voltage crosses the Turn-on Threshold and the output voltage reaches 90% of its nominal value and b) the interval between the point when the converter is enabled by ON/OFF remote control and time when the output voltage reaches 90% of its nominal value. 2401 Stanwell Drive, Concord Ca. 94520 Input Source Impedance Minimum required input capacitance, mounted close to the input pins of the converter, is 1000F with ESR < 0.1. Several criteria need to be met when choosing input capacitor: a) type of capacitor, b) capacitance to provide additional energy storage, c) RMS current rating, d) ESR value that will ensure that output impedance of the input filter is lower than input impedance of the converter and its variation over the temperature. Since inductance of the input power cables could have significant voltage drop due to rate of change of input current di(in)/dt during transient load operation, an external capacitor on the output of the converter is also Fax: 925-687-3333 Ph: 925-687-4411 Page 8 of 22 www.calex.com Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS required to reduce di(in)/dt. Another constraint is minimum rms current rating of the input capacitors which is application dependent. One component of input rms current is high frequency component at switching frequency of the converter (typ. 400kHz) and is specified under "Input terminal ripple current" iC. Typical values at full rated load and 24 Vin are provided in Section "Characteristic Waveforms" for each model. It is recommended to use ceramic capacitors for attenuating this component of input terminal ripple current, which is also required to meet requirement for conducted EMI (See EMI Section). The second component of the input ripple current is due to pulsating load current being reflected to the input. An electrolytic capacitors, usually used for this purpose, need to be selected accordingly. ESR of the electrolytic capacitors, need to be carefully chosen taken into account temperature dependence. Output Capacitor Similar considerations apply for selecting external output capacitor. For additional high frequency noise attenuation use of ceramic capacitors or very low ESR electrolytic capacitors is recommended while in order to provide stability of the converter during high pulsating loads high value electrolytic capacitor is required. It is recommended to use several electrolytic capacitors in parallel in order to reduce effective ESR and support required RMS pulsating load current. ESR temperature dependence needs to be taken into account. Recommended output capacitors for various models, used for obtaining characteristic waveforms are given in Table 1 ("Test Configuration" section). ON/OFF (Pins 1 and 2) The ON/OFF pin is used to turn the power converter on or off remotely via a system signal and has positive logic. A typical connection for remote ON/OFF function is shown in Fig. 1. 12V is applied between +ON/OFF pin -ON/OFF pin. See the Electrical Specifications for logic high/low definitions. The negative logic version turns on when the +ON/OFF pin is at logic low and turns off when at logic high. The converter is on when the +ON/OFF pin is either shorted to -ON/OFF pin or kept below 0.8V. The converter is off when the +ON/OFF pin is either left open or external voltage not more than 12V is applied between +ON/OFF pin and -ON/OFF pin. See the Electrical Specifications for logic high/low definitions. The +ON/OFF pin is internally pulled up to typically 4.5V via resistor and connected to internal logic circuit via RC circuit in order to filter out noise that may occur on the ON/OFF pin. The -ON/OFF pin is internally connected to --INPUT. 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 0.36mA at a low level voltage of 0.8 V. During logic high, the typical maximum voltage at ON/OFF pin (generated by the converter) is 4.5V, and the maximum allowable leakage current is 160A. If not using the remote on/off feature leave the +ON/OFF pin open. TTL Logic Level - The range between 0.81V and 2V is considered the dead-band. Operation in the dead-band is not recommended. External voltage for ON/OFF control should not be applied when there is no input power voltage applied to the converter. 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 approx. 50% of the nominal value of output voltage, the converter will shut down. Once the converter has shut down, it will attempt to restart every 2 seconds until the overload or short circuit conditions are removed or the output voltage rises above 45% of its nominal value within 100 msec. Once the output current is brought back into its specified range, the converter automatically exits the hiccup mode and continues normal operation. Fig. 1: 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 either left open or external voltage greater than 2V and not more than 2401 Stanwell Drive, Concord Ca. 94520 In case of startup into short circuit, internal logic detects short circuit condition and shuts down converter typically 5 msec after the condition is detected. The converter will attempt to restart after 2 seconds until short circuit condition exists. Fax: 925-687-3333 Ph: 925-687-4411 Page 9 of 22 www.calex.com Email: sales@calex.com ECO 170203-4, 170227-2, 170802-1, 171121-1 1000 WATT FXP SERIES DC/DC CONVERTERS Output Overvoltage Protection (OVP) The converter will shut down if the output voltage across +OUT (Pins 5 and 6) and -OUT (Pins 8 and 9) 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 2 seconds until the OVP condition is removed. Sense function is not used for remote regulation, the user should connect SENSE+ (Pin 11) to +OUT (Pins 5 and 6) at the converter pins. Note that SENSE- (Pin 10) is internally connected to -OUT (Pins 8 and 9) and should be used for connecting Trim-down resistor when trimming function is used. Do not connect this pin to -OUT externally. Note that OVP threshold is set for nominal output voltage and not trimmed output voltage value or remote sense voltage. Overtemperature Protection (OTP) The FXP converters have non-latching overtemperature protection. It will shut down and disable the output if temperature at the center of the base plate exceeds a threshold of typical 108C for 9Vin, 112 C for 12Vin and 115 C for 24Vin/36Vin. Measured with FXP converter soldered to 5" x 3.5" x 0.07" 4 layers/ 2 Oz Cooper FR4 PCB. The converter will automatically restart when the base temperature has decreased by approximately 20C. Safety Requirements Basic Insulation is provided between input and the output. The converters have no internal fuse. To comply with safety agencies requirements, a fast-acting or timedelay fuse is to be provided in the unearthed lead. Recommended fuse values are: a) 140A for 9V