Technical Reference Notes ALO25F24 (Single Output 8th Brick) ALO25F24 Single Output 8th Brick: Open-Frame Module The ALO25F24 is Astec’s 8th Brick industry standard offering. Operating from an input voltage range of 18V to 36V. It delivers up to 25A max current at 3.3V output voltage. It provides tight regulation and exhibits clean and monotonic output start up characteristics. This model comes with industry standard features such as Input UVLO; Enable On/Off, OCP, OVP and OTP; Output Trim; Differential Remote Sense pins. Open frame construction is available with TH and SMT termination. With its wide operating temperature range of -40°C to 85°C ambient, the converter is deployable into almost any environment. Electrical Parameters Input Input Range Input Surge 18-36 VDC 50V / 100ms Control Enable TTL compatible (Positive or Negative Logic Enable Options) Output Special Features • • • • • • • • Industry Standard 8th Brick Footprint Open frame construction Low Ripple and Noise Regulation to zero load High Capacitive Load Start-up Fixed Switching Frequency Industry standard features: Input UVLO; Enable; OVP, OCP and OTP; Output Trim, Remote Sense Meets Basic Insulation Load Current Line/Load Regulation Ripple and Noise Output Voltage Adjust Range Transient Response Remote Sense Over Current Protection Over Voltage Protection Over Temperature Protection 3.3V @ 25A max (PO = 82.5W) < 1% VO 75mVP-P ±10% VO 5% Typical deviation 50% to 75% Load Change 100µ µs settling time (Typ) +10%VO 120% (Typ) 130% (Typ) 103°°C Environmental Specifications Safety • • • UL + cUL 60950, Recognized EN60950 through TUV-PS -40ºC to 85ºC Operating Temperature -40ºC to 125ºC Storage Temperature MTBF > 1 million hours MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H SHEET 1 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Electrical Specifications ABSOLUTE MAXIMUM RATINGS Stresses in excess of the absolute maximum ratings can cause permanent damage to the converter. Functional operation of the device is converter is not implied at these or any other conditions in excess of those given in the operational section of the specs. Exposure to absolute maximum ratings for extended period can adversely affect device reliability. Parameter Input Voltage Continuous Transient (100ms) Device Symbol Min Typical Max Unit All Vin Vin trans - - 36 50 Vdc All All All All All All TA TSTG PO,MAX -40 -40 10 - - 1500 85 125 85 25 82.5 Vdc ºC ºC % Vdc W Symbol VIN Min 18 Typical 24 Max 36 Unit Vdc 17.2 15.8 - 17.95 16.50 Vdc 5 1 - - 6.0 ms - - 4.6 W - 6 - mAp-p All - - 1.7 V/ms All - - 5 Apk I/O Isolation (Conditions 50µA for 5 sec, slew rate of 1500V/10sec) Input-to-Output Operating Temperature Storage Temperature Operating Humidity Max Voltage at Enable Pin Max Output Power INPUT SPECIFICATIONS Parameter Operating Input Voltage Range Input Under-Voltage Lock-out T_ON Threshold T_OFF Threshold Input Line Drop Out Time (25°C) - within overshoot spec - within 450mV overshoot Max Input Current 1 (VIN = VIN, Min ; IO = IO, Max) Max Pdiss @ IO = 0A (VIN = VIN, Nom) Temperature: TA = 25°C Input Ripple Current 2 5Hz to 20MHz Input Voltage Rise Time 10% to 90% of Vout Inrush Current dIIN/dt MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H Device All All All All All VIN VIN Iinmax All All II1 A SHEET 2 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Electrical Specifications (continued) OUTPUT SPECIFICATIONS Parameter Output Voltage Set point VIN = VIN, Min to VIN, Max IO = IO, Max Output Regulation Line VIN = VIN, Min to VIN, Max Load IO = IO, Min to IO, Max Temperature: TA = -40°C to 85°C Output Ripple and Noise 3 Peak-to-Peak: (5Hz to 20MHz) External Load Capacitance Capacitor ESR Output Current 4 Output Current-limit Inception VOUT = 90% VO, Set ; TA = 25°C Output Over Voltage Protection Over Temperature Protection Device All Symbol VO, SET Min 3.24 Typical 3.30 Max 3.35 Unit Vdc All - - - ± 0.20 % - - - ± 0.20 - - - ± 1.00 All - - 40 75 mVp-p All - All All IO IO 15 0 26.5 - 15,000 25 35 µF mΩ A A All All VO 3.9 103 4.1 - 4.9 117 °C All η 87 88 - % All - - - 15 ms All - - - 15 ms All - - - 15 ms All All All - 580 90 660 - 740 10 110 kHz %VO %VO All - 0.01 - - V/ms - 0 2.95 - 0.8 20 V V - 2.95 0 - 20 0.8 V V V (AVG. PCB TEMP) Efficiency VIN = VIN, Nom; IO = IO, Max TA = 25ºC Turn On Response Time VIN = VIN, Min toVIN, Max Enable to Output Turn-On Delay VIN = VIN, Min toVIN, Max IO = IO, Min to IO, Max + VIN to Output Turn-On Delay Enable Pin: Active VIN = VIN, Nom IO = IO, Max Switching Frequency Output Voltage Remote Sensing Output Voltage Trim Range 5 Output Enable ON/OFF 6 Enable Signal Slew Rate Negative Enable (“N” suffix) Enable Pin Voltage: Mod-ON Mod-OFF Positive Enable (No suffix) Enable Pin Voltage: Mod-ON Mod-OFF MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H SHEET 3 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Electrical Specifications (continued) OUTPUT SPECIFICATIONS Parameter Dynamic Response CO = 0µF Device Symbol ∆IO/∆t - Peak Deviation Load Change from IO = 50% to 75% of IO, Max : Settling Time to VO, Set Tolerance All Peak Deviation Load Change from IO = 50% to 25% of IO, Max : Settling Time to VO, Set Tolerance Output Overshoot At T-on / t-off Passive Resistive Full Load T < 0°C All All All Min Typical Max Unit - 0.1 - A/µs - - 5 - - 100 - 300 µs 3 %VO - - - 4 %VO 100 %VO µs 300 5 %VO Note: 1. The converter is not internally fused. An input line fuse such as Littlefuse 3AB type must be used. 2. Refer to Figure 1 for the external input capacitance required. 3. Refer to Figure 2 for output ripple and noise test measurement setup. 4. Output power derating applies at elevated temperature. Refer to Figure 11. 5. Refer to the output trim equations provided (Equations 1 and 2). 6. For temperature greater than -20°C, minimum pin disable time is 100ms. For temperature less than -20°C, minimum pin disable time is 1s. SAFETY AGENCY / MATERIAL RATING / ISOLATION Parameter Safety Approval Device All Material Flammability Rating Parameter Input to Output Capacitance Input to Output Resistance Input to Output Insulation Type All Device All All All MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H UL/cUL 60950, 3rd Edition – Recognized EN 60950 through TUV UL94V-0 Symbol Min Typical Max 1000 TBD Basic - Unit pF Ohms - SHEET 4 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Electrical Specifications (continued) TO OSCILLOSCOPE Vi(+) Ltest 12 uH BATTERY Cs 220 uF ESR < 0.1 OHM @ 20 ºC, 100 kHz 33 uF ESR < 0.7 OHM @ 20 ºC, 100 kHz Vi(-) Measure input reflected-ripple current with a simulated source inductance (Ltest) of 12uH. Capacitor Cs offsets possible battery impedance. Measure current as shown above. Figure 1. Input Reflected Ripple Current Measurement Setup. COPPER STRIP Vo(+) 0.1 uF 10 uF SCOPE RESISTIVE LOAD Vo(-) Use a 0.1µF @50V X7R ceramic capacitor (connected an inch away from the output terminals of the UUT) and a 10µF @ 25V tantalum capacitor (2 inches away from the output terminals of the UUT). Scope measurement should be made using a BNC socket, positioned 3 inches away from output terminals of the converter. Figure 2. Peak to Peak Output Noise Measurement Setup. MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H SHEET 5 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Basic Operation and Features INPUT UNDER VOLTAGE LOCKOUT To prevent any instability to the converter, which may affect the end system, the converter have been designed to turn-on once VIN is in the voltage range of 17.2-17.95 VDC. Likewise, it has also been programmed to turn-off when VIN drops down to 15.8-16.5 VDC. OUTPUT VOLTAGE ADJUST/TRIM The converter comes with a TRIM pin (PIN 6), which is used to adjust the output by as much as 90% to 110% of its set point. This is achieved by connecting an external resistor as described below. To INCREASE the output, external Radj_up resistor should be connected between TRIM PIN (Pin6) and +SENSE PIN (Pin 7). Please refer to Equation (1) for the required external resistance and output adjust relationship. -Vin -Vout -Sense Enable Rload Vadj Radj_up +Sense Equation (1a): Radj_up = +Vin +Vout 5.1 × Voset × ( 100 + ∆%) 510 − − 10.2 ΚΩ ∆% 1.225 × ∆% Figure 3. Trim UP test configuration (Pin Side Up). To DECREASE the output, external Radj_down resistor should be connected between TRIM pin (Pin 6) and -SENSE PIN (Pin 5). Please refer to Equation (2) for the required external resistance and output adjust relationship. -Vin -Sense Radj_down Enable Equation (2): Radj_down -Vout Rload Vadj +Sense 510 − 10.2 ⋅ kΩ ∆% Where: ∆% = percent change in output voltage MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H +Vin +Vout Figure 4. Trim DOWN test configuration (Pin Side Up). SHEET 6 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Basic Operation and Features (continued) OUTPUT ENABLE The converter comes with an Enable pin (PIN 2), which is primarily used to turn ON/OFF the converter. Both a Positive (no “N” suffix required) and a Negative (suffix “N” required) Enable Logic options are being offered. For Positive Enable, the converter is turned on when the Enable pin is at logic HIGH or left open. The unit turns off when the Enable pin is at logic LOW or directly connected to -VIN. On the other hand, the Negative Enable version turns unit on when the Enable pin is at logic LOW or directly connected to -VIN. The unit turns off when the Enable pin is at Logic HIGH. OVER CURRENT PROTECTION (OCP) The Over Current Protection is latching with auto-restart. The converter shuts down once the output current reaches the OCP range. The converter will attempt to restart until the fault is removed. Latching OCP mode is available as an option (no model part number assigned). This feature is only for module protection and no intention to customer application. OUTPUT OVER VOLTAGE PROTECTION (OVP) The Over Voltage Protection circuit is latching with auto-restart. The converter will latch-off and attempt to restart until the fault is removed. Latching OVP mode is available as an option (no model part number assigned). OVER TEMPERATURE PROTECTION (OTP) The Over Temperature Protection circuit will shutdown the converter once the average PCB temperature reaches the OTP range. This feature prevents the unit from overheating and consequently going into thermal runaway, which may further damage the converter and the end system. Such overheating may be an effect of operation outside the given power thermal derating conditions. Restart is possible once the temperature of the sensed location drops to less than 103°C. REMOTE SENSE The remote sense pins can be used to compensate for any voltage drops (per indicated max limits) that may occur along the connection between the output pins to the load. Pin 7 (+Sense) and Pin 5 (-Sense) should be connected to Pin 8 (+Vout) and Pin 4 (Return) respectively at the point where regulation is desired. The combination of remote sense and trim adjust cannot exceed 110% of VO. When output voltage is trimmed up (through remote sensing and/or trim pin), output current must be derated and maximum output power must not be exceeded. MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H SHEET 7 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Performance Curves Pow er Dissipation vs. Output Current, TA=25°C Efficiency vs. Output Current, TA=25°C 90% 12 Power Dissipation [W] 95% 14 Efficiency [%] 85% 80% 75% 70% 65% Vin = 18Vdc Vin = 24Vdc 60% 10 8 6 4 Vin = 18Vdc Vin = 24Vdc 2 Vin = 36Vdc Vin = 36Vdc 55% 0 0 5 10 15 Output Current [A] 20 25 0 5 10 15 Output Current [A] 20 Figure 5. Efficiency vs. Load Current at IO = Full Load, TA = 25°C (ambient temperature). Figure 6. Power Dissipation vs. Load Current at IO = Full Load, TA = 25°C (ambient temperature). Figure 7. Output Turn On Response Time at VIN = 24V, IO = Full Load TA = 25°C. Figure 8. Output Ripple Waveform at VIN = 24Vdc, IO = Full Load, TA = 25°C. MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H 25 SHEET 8 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Performance Curves Figure 9. Output Transient Response at TA = 25°C; Peak Deviation (Hi - Lo). Figure 10. Output Transient Response at TA = 25°C; Peak Deviation (Lo - Hi). ALO25F24 Derating Curve @ 24Vin 25 Output Current 20 15 10 400 LFM 300 LFM 200 LFM 100 LFM 0 LFM 5 0 25 40 55 70 Am bient Tem p (°C) 85 Figure 11. Output Current vs. Temperature at VIN =24V, IO = Full Load, TA = 25°C. MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H Figure 12. Enable to Output Turn On Time at VIN =24V, IO = Full Load, TA = 25°C. SHEET 9 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Input Filter for FCC Class B Conducted Noise A reference design for an input filter that can provide FCC Class B conducted noise levels is shown below (See Figure 13). Two common mode connected inductors are used in the circuit along with balanced bypass capacitors to shunt common mode currents into the ground plane. Shunting noise current back to the converter reduces the amount of energy reaching the input LISN for measurement. The application circuit shown has an earth ground (frame ground) connected to the converter output (-) terminal. Such a configuration is common practice to accommodate safety agency requirements. Grounding an output terminal results in much higher conducted emissions as measured at the input LISN because a hard path for common mode current back to the LISN is created by the frame ground. “Floating” loads generally result in much lower measured emissions. The electrical equivalent of a floating load, for EMI measurement purposes, can be created by grounding the converter output (load) through a suitably sized inductor(s) while maintaining the necessary safety bonding. FILTER PARTS LIST CKT CODE Common Mode Choke X-Cap Y-Cap Cin DESCRIPTION CTX01-15091 Cooper Electronic Technologies 0.47 µF X 4pcs 22 nF X 4 pcs 220µF X 1pc Figure 13: Class B Filter Circuit MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H SHEET 10 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Mechanical Specifications Parameter Dimension Weight PIN ASSIGNMENT 1 2 3 4 Device All Symbol L W H All +VIN ENABLE -VIN -Vo Min - Typ 2.30 [58.42] 0.80 [20.32] - Max 0.32 [8.13] Unit in [ mm ] in [ mm ] in [ mm ] - 24 [0.85] - g [oz] 5 6 7 8 -SENSE TRIM +SENSE +Vo Figure 14A. Mechanical Outline (Pin Version) MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H SHEET 11 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) Mechanical Specifications (continued) Figure 14B. Mechanical Outline (Surface Mount) Figure 15. Recommended Pad layout for SMT (Suffix “S”) version. MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H SHEET 12 OF 13 Technical Reference Notes ALO25F24 (Single Output 8th Brick) RECOMMENDED REFLOW PROFILE SOLDERING CONSIDERATIONS 240 When hand soldering, the iron temperature should be maintained at 425°C and applied to the converter pins for less than 5 seconds. Longer exposure can cause internal damage to the converter. Cleaning can be performed with cleaning solvent IPA or with water. PEAK TEMPERATURE 200°°C - 230°°C 220 200 TEMPERATURE (deg C) The ALO25F24 converter is compatible with standard wave soldering techniques. When wave soldering, the converter pins should be preheated for 20-30 seconds at 110°C and wave soldered at 260°C for less than 10 seconds. 183°°C 180 REFLOW ZONE 160 140 < 80 sec 110°°C 120 100 120 - 180 sec PRE-HEAT ZONE 80 60 SLOPE < 4°°C /sec 40 20 For SMT terminated modules, refer to Figure 16 for the recommended reflow profile. 0 0 30 60 90 120 150 180 210 240 270 300 TIME (seconds) Figure 16. Recommended reflow profile for SMT modules. PART NUMBERING SCHEME CONSTRUCTION A w L = Open frame O/P CURRENT O/P VOLTAGE Vin Enable xx y 24 N O 25 = 25A F = 3.3V N = Negative No suffix “N” = Positive default - PIN LENGTH TERMINATION 6 S 6 = 3.7mm No suffix “-6” = 5mm default S = SMT Termination No suffix “-S” = TH termination Note: 1) For Through Hole (TH) termination: - Std pin length is 5mm nominal (min: 0.189 [4.8]; max: 0.205 [5.2] / in [mm]) - “-6” option is 3.7mm nominal (min: 0.137 [3.5]; max: 0.152 [3.9] / in [mm]) - Pins 4 & 8 diameter: ∅ = 0.062 [1.57], others: ∅ = 0.04 [1.0] (6X) Please call 1-888-41-ASTEC for further inquiries or visit us at www.astecpower.com MODEL: ALO25F24 AUGUST 23, 2005 - REVISION H SHEET 13 OF 13