TECHNICAL DATASHEET Rev. C CMFA12S24-300 300W DC-DC Chassis Mount Converter 10-36 Vdc Input 24Vdc Output at 12.5A Full-Brick Package Features: 88% Efficient at Full Load 90% Efficiency at 1/2 Load Fast Transient Response Operation to No Load Output Trim ±10% Remote ON/OFF (Active High/Low) Remote Sense Compensation Delivers a Continuous 150W at 25°C with No Air / No Heatsink Very Low Output Ripple Fixed Switching Frequency Output Over Current Foldback Output Short Circuit Protection Over Temperature Protection 1500 V Isolation 100% Burn In Synchronizable UL 60950/CE Mark (PENDING) Description: The CMFA Series is a high-density full brick converter on a chassis mount that incorporates the desired features required in today’s demanding low voltage bus applications. Its unique dual interleaved phase-shifted topology minimizes both input and output noise. When performance, reliability, and low cost are needed, the CMFA Series delivers. (888) 597-WALL www.wallindustries.com Page 1 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET Rev C CMFA12S24-300 Model No. CMFA12S24-300 Technical Specifications All specifications are based on 25°C, Nominal Input Voltage, and Maximum Output Current unless otherwise noted. We reserve the right to change specifications based on technological advances. SPECIFICATION Switching Frequency INPUT (Vin) Operating Voltage Range UVLO Turn On at UVLO Turn Off at UVLO Hysterisis Maximum Input Current (Graph 3) No Load Input Current (Graph 3) Input Current under “Remote Off” Reflected Ripple Current Input Surge Voltage EFFICIENCY (Graph 1) OUTPUT (Vo) Related condition Low Line No Load With L-C filter as shown in Fig. 7. 100 mS Io=12.5A Voltage Set Point ±Sense shorted to ±Vout Voltage Adjustment (Table1) Max Output limited to 300W Load Regulation Line Regulation Temperature Drift ±Sense shorted to ±Vout ±Sense shorted to ±Vout Remote Sense Compensation Ripple Spikes Current Current Limit Over Voltage Limit DYNAMIC RESPONSE Load step / V Recovery Time Turn On Delay Turn On Overshoot Hold Up Time REMOTE ON/OFF Remote ON – Positive logic Remote OFF – Positive logic Remote ON pin Floating - Positive logic ION/OFF Sink current - Positive logic Remote ON – Negative logic Remote OFF – Negative logic Remote ON/OFF pin Floating – Negative logic ION/OFF Sink to pull low – Negative logic ION/OFF Source to drive high – Active High or Low Turn On Delay Turn Off Delay ISOLATION Input-Output Isolation Resistance Isolation Capacitance THERMAL Ambient (Graph 2) Over Temperature Protection Storage Temperature MTBF MECHANICAL Weight (888) 597-WALL Max Output limited to 300W (max. drop in each + and – output trace) 0.1µF Ceramic & 10µF Tantalum 0.1µF Ceramic & 10µF Tantalum Rated maximum output current Power Limited-Dependent upon SENSE compensation and TRIM adjustment Min Nom Max Unit - 600 - KHZ 10 9.5 9.0 - 12 9.7 9.25 0.5 35.7 0.10 1 20 86 36 10 9.5 50 - Vdc Vdc Vdc Vdc A A mA mA Vdc % 24.250 +1% 26.4 +10% 0.2 0.2 0.02 1 Vdc % % % % / °C Vdc 23.74 -1% 21.6 -10% - 24.00 0.05 0.05 0.01 - - 0 50 50 - 240 240 12.5 mV p-p mV p-p A - 17.5 - A 27 30 33 Vdc - V mS mS % mS 5.0 2.0 5.0 1.0 2.0 5.0 4.7 1 1 10 Vdc Vdc Vdc mA Vdc Vdc - Vdc GΩ µF 50% to 100% Io Recovery to within 1% Nominal Vout From Vin (min) to Vout (nom) Full Load Resistive 1 0.4 50 0.0 0 Active High or Active Low (See page 12 for ordering details) TTL high or Open-circuit 2.5 TTL Low Over Operating Voltage Range 4.4 VON/OFF =0V, Vin=75V Max Low to Enable Min High to Disable 2.5 Over Operating Voltage Range 4.4 VON/OFF =0V, Vin=75V Enabled 6 Disabled 1 minute Max. Ambient limited by Derating Curves (Graph 2) Self Resetting Ambient Calculated Using Bellcore TR-332 Method 1 case 3 1500 1 -40 -55 - www.wallindustries.com Vdc 0.010 mA µA mS µS Graph 2 25 110 125 2,212,456 See Figure 1 318 - °C °C °C Hours g Page 2 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET CMFA12S24-300 Rev C Figure 1: Mechanical Dimensions Unit: inches [mm] 8.00 [203.2] 7.000 [177.80] .50 [12.7] 3.500 [88.90] +INPUT +OUTPUT +S SD 3.40 [86.4] 2.875 [73.03] TRIM SYNC -S -INPUT -OUTPUT .000 [0.00] .26 [6.7] DATE CODE LABEL SERIAL NO: UNIT THRU HOLE Ø.125 [3.2] 6X REF PCB THRU HOLE Ø.140 [3.6] 6X REF Ø.143 [3.6] MOUNTING HOLES 6X GROUNDED 6-PLACES TERMINAL SCREW .136 (NO:6)-32UNC 9X .91 [23.0] .24 [6.0] REF Ø.28 [7.1] 6X .000 [0.00] .13 [3.2] 6X REF .000 [0.00] TO ORDER 1. Unit comes with either 3M x 0.5 threaded thru inserts for the chassis mount board or for ø.125 thruhole for the chassis mount board add the suffix "TH" to the model part number. Ex: CMFA12S24-300TH. 2. For Heat Sink Add “HS” suffix to model part number. Ex: CMFA12S24-300HS (888) 597-WALL www.wallindustries.com Page 3 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET Rev C CMFA12S24-300 DESIGN CONSIDERATIONS Under Voltage Lock Out (UVLO) The converter output is disabled until the input voltage exceeds the UVLO turn-on limit. The converter will remain ON until the input voltage falls below the UVLO turn-off limit. There is approximately 0.5V hysteresis in the UVLO circuit. Over Current Protection The converter is internally protected from short circuit and over current conditions. During these fault conditions, the converter output will “hiccup”- (short) or “fold back” - (over current). The converter output will recover once the short or over current fault is removed. Over Temperature Protection The converter is protected from over temperature conditions. Upon exceeding this temperature, the converter will shut down. The converter will automatically recover once it has sufficiently cooled. Output Filter No additional output capacitor is needed for the power supply to operate within stated specifications. However, if it is a requirement to reduce the ripple and noise on the output, additional capacitance may be added. Usually, ceramic MLCC’s capacitor works best for reducing H.F. spike noise. Also, capacitance in the form of a tantalum or aluminum electrolytic capacitor may also be placed across the output in order reduce base ripple, and improve the load transient peak-to-peak voltage deviation. Remote Sense To improve the voltage regulation at the load, route the connections from the -Sense and the +Sense pins to the –Vout and +Vout connections AT the load. This will force the converter to regulate the voltage at the load and not at the pins of the converter. If it is not desired to use the Remotes Sense feature, the –Sense and +Sense pins should be connected to the -Vout and +Vout pins respectively. Fusing It is required that the input to the converter be supplied with a maximum 50 A, 250 V rated fuse. Safety The CMFA series is CE pending and pending approval of the following: UL1950, CUL950, TUV60950 FILE 155800. The isolation provided by the CMFA Series is a Basic insulation in accordance with EN60950. SELV output reliability is maintained only if the input to the CMFA converter is an SELV source. Remote ON/OFF The CMFA Series has Remote ON/OFF (Enable/Disable) capability using TTL logic levels. This function is offered as either Active=TTL High (no suffix) or Active=TTL Low (R suffix), see order details on page 12. For Remote ON/OFF limits, see page 2. Figure 2. Remote (L/E) Synchronization The CMFA series provides synchronization of switching frequencies between multiple FA series power supplies. The synchronization function is accomplished without the need for any added external circuitry. By tying the SYNC pin between CMFA modules, they will all automatically synchronize. If synchronization is not used, the pin should be tied to –Vin. (888) 597-WALL www.wallindustries.com Page 4 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET Rev C CMFA12S24-300 Output Voltage Trim 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. 2. 3. 4. Determine the desired output voltage deviation %. To trim down, solve for resistor value using the “Rtlow” equation. To trim up, solve for resistor value using the “Rthi” equation. Solved resistor values are in KΩ. Figure 3 510 10.2 Rtlow % Figure 4 5.1 Vo (100 %) 510 Rthi 10.2 % 1.2225 % Notes: 1. 2. 3. 4. 5. Maximum trim range is ±10%. This includes remote sense drops if applicable. Output current is limited to specified current when trimming down. Output power is limited to specified power when trimming up. Trim resistors should be placed close to the module. If the trim function is not used, it is advised to leave the trim pin floating / not connected. (888) 597-WALL www.wallindustries.com Page 5 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET CMFA12S24-300 Rev C Graph 1: CMFA12S24-300 Efficiency vs. Output Current 100% 95% EFFICIENCY (%) 90% Low Line 85% 80% Nominal Line 75% High Line 70% 65% 60% 55% 50% 0 2 4 6 8 10 12 14 OUTPUT CURRENT (AMPS) Graph 2: CMFA12S24-300 Max Ambient vs. Output Power OUTPUT POWER (WATTS) 300 250 0 LFM 200 100 LFM 200 LFM 150 300 LFM 400 LFM 100 50 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 AMBIENT TEMPERATURE (DEG. C.) Note: When trimming the output high, Io vs. Ambient is derated by power. i.e.: from Graph 2, find the maximum current at the desired ambient and airflow, and multiply this current by the nominal voltage (24V) to get the maximum power. Divide this power by the desired trimmed high voltage to get the maximum current at that ambient. When trimming low, the maximum current stays the same as shown in graph 2. (888) 597-WALL www.wallindustries.com Page 6 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET CMFA12S24-300 Rev C Graph 3: Input Current vs. Input Voltage 40.00 INPUT CURRENT (AMPS) 35.00 30.00 Io=3.12A 25.00 Io=6.25A 20.00 Io=9.37A 15.00 Io=12.5A 10.00 5.00 0.00 0 5 10 15 20 25 30 35 40 INPUT VOLTAGE POWER DISSIPATION (WATTS) Graph 4: Power Dissipation vs. Input Voltage 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Io=0A Io=3.12A Io=6.25A Io=9.37A Io=12.5A 0 5 10 15 20 25 30 35 40 INPUT VOLTAGE (888) 597-WALL www.wallindustries.com Page 7 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET CMFA12S24-300 Rev C Graph 5: Input Current Characteristics at Light Load 3.5 3 Input Current 2.5 No Load 0.125A 0.250A 0.500A 0.750A 1.000A 2 1.5 1 0.5 0 10 15 20 25 30 35 40 Input voltage (888) 597-WALL www.wallindustries.com Page 8 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET Rev C CMFA12S24-300 TEST SETUP: The CMFA12S24-300 specifications are tested with the following configurations: Regulation and Efficiency Setup To ensure that accurate measurement are taken, the voltage measurements are taken directly at the terminals of the module. This minimizes errors due to contact and trace lengths between the load and the output of the supply. The following diagram is of the test setup. Figure 5: Regulation and Efficiency Probe Setup Output Ripple Voltage Setup The module is tested with a 0.1µF ceramic capacitor in parallel with a 10µF tantalum capacitor across the output terminals. Unless otherwise specified, bandwidth is limited to 20MHZ. Figure 6: Ripple Voltage Probe Setup (888) 597-WALL www.wallindustries.com Page 9 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET Rev C CMFA12S24-300 Input Reflected Ripple Current and Input Ripple Voltage Setup The module is tested for input reflected ripple current (Irrc). The input ripple voltage is also measured at the pins with and without an additional 33µF electrolytic capacitor. To reduce either the input ripple current or voltage additional capacitors and/or an inductor may be added to the input of the converter. Figure 7: Ripple Current Setup Converter Thermal Consideration The converter is designed to operate without convective cooling if the de-rating curves are followed. The converter can operate at higher temperatures and higher output currents if airflow and/or a heatsink are applied. Airflow should be aligned lengthwise to the converter’s heatsink fins for optimum heat transfer. See Graph 2 for de-rating curves or contact factory for additional thermal information. Figure 8: Airflow Orientation (888) 597-WALL www.wallindustries.com Page 10 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET Rev C CMFA12S24-300 Paralleling Converters The CMFA series converters may be paralleled both for redundancy and for higher output current. However, in order to do this, a highcurrent, low Vf, Schottky diode must be placed at the +Vo pin of each supply as shown in Figure 9. To improve sharing, tie the two TRIM pins together. The converters may be trimmed by adding a resistor value from each TRIM pin to ±RS pin, or alternatively, a single resistor of half the value from the common TRIM pins to the common ±RS pins. Figure 9: Paralleling Converters (888) 597-WALL www.wallindustries.com Page 11 of 12 WALL INDUSTRIES, INC. TECHNICAL DATASHEET CMFA12S24-300 Rev C Ordering Information: Part Number Example: CMFA 12 S 24 – 300 R TH Series Designation Nominal Input Voltage Single Output Nominal Output Voltage Options Maximum Output Power No Suffix TH HS Threaded Thru Inserts (3M x 0.5) Thru-Hole Inserts Heat sink Options No suffix Active High Enable (standard) R Active Low Enable (option) Company Information: Wall Industries, Inc. has created custom and modified units for over 40 years. Our in-house research and development engineers will provide a solution that exceeds your performance requirements on time and on budget. Our ISO9001-2000 certification is just one example of our commitment to producing a high quality, well-documented product for our customers. Our past projects demonstrate our commitment to you, our customer. Wall Industries, Inc. has a reputation for working closely with its customers to ensure each solution meets or exceeds form, fit and function requirements. We will continue to provide ongoing support for your project above and beyond the design and production phases. Give us a call today to discuss your future projects. Contact Wall Industries for further information: Phone: Toll Free: Fax: E-mail: Web: Address: (888) 597-WALL (603)778-2300 (888)587-9255 (603)778-9797 [email protected] www.wallindustries.com 5 Watson Brook Rd. Exeter, NH 03833 www.wallindustries.com Page 12 of 12