PT4120 Series 20-W 48-V Input Isolated DC/DC Converter SLTS092B (Revised 2/26/2002) Features • Input Voltage Range: 36V to 75V • 20W Rated • 82% Efficiency • 1500 VDC Isolation • Low Profile (8.5 mm) • Small Footprint: 1.52in x 1.73in • Remote On/Off • • • • • • • Short Circuit Protection Over Temperature Shutdown Under-Voltage Lockout UL1950 Recognized CSA 22.2 950 Certified EN60950 Approved 4×106 Hrs MTBF Description Ordering Information Pin-Out Information The PT4120 power modules are a series of isolated DC/DC converters housed a lowprofile package. Rated for 20 watts or 5A, the series includes standard output voltages ranging from as low as 1.5VDC to 15VDC. The output may be adjusted ±10% of nominal. These converters are ideal for Telecom, Industrial, Computer, and other distributed power applications that require input-tooutput isolation. Using multiple PT4120 modules, system designers can implement a complete custom power supply solution. The flexibility of full isolation also allows the input or output to be configured for negative voltage operation. The PT4120 series requires no additional components for proper operation. PT4121H PT4122H PT4123H PT4124H PT4125H PT4126H PT4127H PT4128H PT4129H Pin = 3.3V/5A (16.5W) = 5.0V/4A = 12.0V/1⋅6A = 15.0V/1⋅3A = 5.2V/3·8A = 1.5V/5A (7.5W) = 1.8V/5A (9W) = 2.5V/5A (12.5W) = 1.65V/5A (8·25W) Order Suffix Package Code * A C Horizontal SMD (EGD) (EGE) * Previously known as package style 710. (Reference the applicable package code drawing for the dimensions and PC board layout) Standard Application +VIN –VIN 3 +VOUT 4 –VOUT PT4120 LOAD 2 1 Remote On/Off 5 6 Q1 BSS138 For technical support and more information, see inside back cover or visit www.ti.com VOAdj Remote On/Off 2 –Vin 3 +Vin 4 –Vout 5 +Vout 6 Vout Adjust † † † For further information, see application notes. PT Series Suffix (PT1234x ) Case/Pin Configuration Function 1 PT4120 Series 20-W 48-V Input Isolated DC/DC Converter Specifications (Unless otherwise stated, Ta =25°C, V in =48V, Cout =0µF, and Io =Io max) Characteristic Symbol Output Current Io Conditions Over Vin range Input Voltage Range Set Point Voltage Tolerance Vin Vo tol Over Io Range Temperature Variation Line Regulation Regtemp Regline –40° ≤Ta ≤ +85°C Over Vin range Load Regulation Regload Over Io range Total Output Voltage Variation ∆Votot Includes set-point, line load, –40° ≤Ta ≤ +85°C Efficiency η Min Vo = 15V Vo = 12V Vo =5.0V Vo ≤ 3.3V Vo ≥5.0V Vo ≤3.3V Vo ≥5.0V Vo ≤3.3V Vo ≥5.0V Vo ≤3.3V Vo ≥5.0V Vo ≤3.3V Vo = 15V Vo = 12V Vo =5.0V Vo =3.3V Vo =1.8V Vo ≥ 5.0V Vo ≤ 3.3V Vo Ripple (pk-pk) Vr 20MHz bandwidth Transient Response ttr 0.1A/µs, load step 50% to 100% Iomax Vo over/undershoot Vo ≥ 5.0V Vo ≤ 3.3V ∆Vtr Short Circuit Current Switching Frequency Isc ƒs Under-Voltage Lockout Remote On/Off (Pin 1) Input High Voltage Input Low Voltage Input Low Current UVLO VIH VIL IIL Over Vin range Referenced to –Vin (pin 2) Standby Input Current Internal Input Capacitance External Output Capacitance Isolation Voltage Capacitance Resistance Operating Temperature Range Storage Temperature Reliability Iin standby Cin Cout pins 1 & 2 connected Ta Ts MTBF Mechanical Shock — Mechanical Vibration — Weight Flammability — — Over Vin range — Per Bellcore TR-332 50% stress, Ta =40°C, ground benign Per Mil-Std-883D, method 2002.3, 1mS, half-sine, mounted to a fixture Per Mil-Std-883D, method 2007.2, 20-2000Hz, soldered in a PC board — Materials meet UL 94V-0 Between +Vo and –Vo Input to output Vo ≥ 12.0V Vo ≤ 5.2V PT4120 SERIES Typ Max Units 0.1 (1) 0.1 (1) 0.1 (1) 0.1 (1) 36.0 — — — — — — — — — — — — — — — — — — — — 600 800 — — — — — 48.0 ±1 — ±0.5 ±0.2 ±7 ±0.4 ±13 ±2 ±67 86 83 82 78 67 0.5 15 100 ±3.0 ±150 2xIomax 650 850 31 1.3 1.6 4.0 5.0 75.0 ±1.5 ±50 — ±1.0 ±33 ±1.0 ±33 — — — — — — — — — — — — — 700 900 — 2.5 –0.2 — — — 0 1500 — 10 -40 -40 — — –10 7 0.5 — — 1100 — — — 7.0 (2) +0.8 – 50 — 200 — — — +85 (3) +125 µA mA µF µF V pF MΩ °C °C 4.0 — — 106 Hrs — 500 — G’s — 15 — G’s — 23 — grams A VDC %Vo mV %Vo %Vo mV %Vo mV %Vo mV % %Vo mVpp µs %Vo mV A kHz V V Notes: (1) The DC/DC converter will operate at no load with reduced specifications. (2) The Remote On/Off (pin 1) has an internal pull-up, and if it is left open circuit the PT4120 will operate when input power is applied. Refer to the application notes for interface considerations. (3) See Safe Operating Area curves or contact the factory for the appropriate derating. For technical support and more information, see inside back cover or visit www.ti.com Typical Characteristics PT4120 Series 20-W 48-V Input Isolated DC/DC Converter PT4121, 3.3 VDC PT4122, 5.0 VDC (See Note A) PT4123, 12.0 VDC (See Note A) Efficiency vs Output Current Efficiency vs Output Current 90 Efficiency vs Output Current 90 90 36.0V 48.0V 75.0V 70 60 85 80 Vin 75 36.0V 48.0V 75.0V 70 65 60 Efficiency - % Vin Efficiency - % Efficiency - % 85 80 55 50 1 2 3 4 5 0.5 1 1.5 2.5 3 3.5 0 75.0V 48.0V 36.0V 6 4 0 4 Vin 10 75.0V 48.0V 36.0V 8 6 5 1 1.5 3 3.5 3 2 0 0 3 4 5 0.4 75.0V 48.0V 36.0V 60 50 40 30 20 1 1.5 2 2.5 3 3.5 5 1.6 Vin 75.0V 48.0V 36.0V 2 4 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Iout (A) Safe Operating Area, Vin =48V (See Note B) 90 80 Airflow 70 200LFM 120LFM 60LFM Nat conv 60 50 40 30 20 4 1.4 0 0.5 Ambient Temperature (°C) 200LFM 120LFM 60LFM Nat conv 1.2 3 Safe Operating Area, Vin =48V (See Note B) Ambient Temperature (°C) Airflow 70 1 1 90 80 0.8 4 Iout (A) Safe Operating Area, Vin =48V (See Note B) 0.6 5 Vin 0 90 Iout (A) 0.2 Power Dissipation vs Output Current 2 0 3 20 6 3 1 2 75.0V 48.0V 36.0V 30 Iout (A) 4 1 1 Vin 4 Pd - Watts 75.0V 48.0V 36.0V Pd - Watts Pd - Watts 2.5 5 Vin 1.6 40 Power Dissipation vs Output Current Iout (A) Ambient Temperature (°C) 2 6 4 1.4 50 Iout (A) 5 1.2 0 0.5 Iout (A) Power Dissipation vs Output Current 1 10 0 6 0.8 60 12 0 3 0.6 Ripple vs Output Current 2 0 0.4 70 4 2 2 0.2 Iout (A) Ripple - mV 8 Ripple - mV Vin 1 60 4 14 10 Ripple - mV 2 16 0 65 Ripple vs Output Current Ripple vs Output Current 2 36.0V 48.0V 75.0V 70 Iout (A) 12 1 Vin 75 50 0 Iout (A) 0 80 55 50 0 (See Note A) 80 Airflow 70 200LFM 120LFM 60LFM Nat conv 60 50 40 30 20 0 1 2 3 4 Iout (A) 0 0.25 0.5 0.75 1 Iout (A) Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter. Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures For technical support and more information, see inside back cover or visit www.ti.com 1.25 1.5 1.75 Application Notes PT4120/4140 Series Using the Remote On/Off Function on the PT4120/ PT4140 Series of Isolated DC/DC Converters For applications requiring output voltage on/off control, the PT4120/4140 series of DC/DC converters incorporate a remote on/off function. This function may be used in applications that require battery conservation, power-up/ shutdown sequencing, and/or to co-ordinate the powerup of the regulator for active in-rush current control. (See the related application note, AN21). This function is provided by the Remote On/Off control, pin1. If pin 1 is left open-circuit, the converter provides a regulated output whenever a valid source voltage3 is applied between +Vin(pin 3), and –Vin (pin 2). Applying a low-level ground signal 1 to pin 1 will disable the regulator output 5. Table 1 provides details of the threshold requirements for the Remote On/Off pin. Figure 1 shows how a discrete MOSFET (Q1) 4, may be referenced to the negative input voltage rail and used with this control input. Table 1 Inhibit Control Thresholds Parameter min max Enable (VIH) 2.5V (Open Circuit) 2, 4 Disable (VIL) –0.3V 0.8V Notes: 1. The on/off control uses -Vin (pin 2), the primary side of the converter as its ground reference. All voltages specified are with respect to -Vin. 2. The on/off control internal circuitry is a high impedance 10µA current source. The open-circuit voltage may be as high as 8.3Vdc. 3. The PT4120/40 series incorporates an “Under Voltage Lockout” (UVLO) function. This function automatically inhibits the converter output until there is sufficient input voltage for the converter to produce a regulated output. Table 2 gives the applicable UVLO thresholds. Table 2 UVLO Thresholds Series UVLO Threshold PT4120 PT4140 31V Typical 15V Typical 6. Keep the on/off transition to less than 1ms. This prevents erratic operation of the ISR, whereby the output voltage may drift un-regulated between 0V and the rated output during power-up. Figure 1 +V o 3 +V in +V in +Vout 5 PT4121 2 –V in –V out Remote On/Off 1 4 V o (adj) 6 –V o Q1 BSS138 Inh Note 2 –V in Turn-On Time: The converter typically produces a fully regulated output voltage within 50ms after the application of power, or the removal of the low voltage signal 6 from the Remote On/Off pin. The actual turn-on time will vary with the input voltage, output load, and the total amount of capacitance connected to the output. Using the circuit of Figure 1, Figure 2 shows the output voltage and input current waveforms of a PT4121 after Q1 is turned off. The turn off of Q1 corresponds to the drop in Q1 Vgs voltage. The waveforms were measured with a 48Vdc input voltage, and 2.75-A resistive load. Figure 2 Vout (2V/Div) Vin Range 36 – 75V 18 – 40V Iin (0.2A/Div) 4. The Remote On/Off input of the PT4120/40 series regulators must be controlled with an open-collector (or open-drain) discrete transistor or MOSFET. Do not use a pull-up resistor. 5. When the converter output is disabled, the current drawn from the input supply is typically reduced to 8mA (16mA maximum). Q1 Vgs (10V/Div) HORIZ. SCALE: 5ms/Div For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT4120/4140 Series Adjusting the Output Voltage of the PT4120/ PT4140 Series of Isolated DC/DC Converters The factory pre-set output voltage of Power Trends’ PT4120 and PT4140 series of isolated DC/DC converters may be adjusted within ±10% of nominal. Adjustment is made from the secondary side of the regulator1 with a single external resistor. For the input voltage range specified in the data sheet Table 1 gives the allowable adjustment range for each model, as Vo (min) and Vo (max). Adjust Up: An increase in the output voltage is obtained by adding a resistor, R2 between pin 6 (Vo adjust), and pin 4 (-Vout). 4. Never connect capacitors to Vo adjust. Any capacitance added to the Vo adjust control pin will affect the stability of the ISR. The values of (R1) [adjust down], and R2 [adjust up], can also be calculated using the following formulas. (R1) = Ko (Va – Vr) Vr (Vo – Va) – Rs kΩ R2 = Ko (Va – Vo) – Rs kΩ Adjust Down: Add a resistor (R1), between pin 6 (Vo adjust) and pin 5 (+Vout). Refer to Figure 1 and Table 2 for both the placement and value of the required resistor, (R1) or R2. Notes: 1. The PT4120 and PT4140 series of DC/DC converters incorporate isolation between the Vin and Vo terminals. Adjustment of the output voltage is made to the regulation circuit on the secondary or output side of the converter. 2. The maximum rated output power for this series is 20W. An increase in the output voltage may therefore require a corresponding reduction in the maximum output current (see Table 1). The revised maximum output current must be determined as follows:Io(max) = 20 A, Va = Original output voltage = Adjusted output voltage = Reference voltage (Table 1) = Multiplier constant (Table 1) = Internal series resistance (Table 1) Where Vo Va Vr Ko Rs Figure 1 + Vo + V in (R1) Adj Down 3 +V in +V out PT4120/40 2 –V in –V out Remote On/Off or 5A, whichever is less. 5 1 –V in 4 R2 Adj Up V o (adj) 6 –V o Where Va is the adjusted ouput voltage. 3. Use only a single 1% resistor in either the (R1) or R2 location. Place the resistor as close to the ISR as possible. Table 1 DC/DC CONVERTER ADJUSTMENT RANGE AND FORMULA PARAMETERS Series Pt # 48V Bus 24V Bus Max Current 2 Vo(nom) Va(min) Va(max) Vr Ω) Ko (V·kΩ Ω) Rs (kΩ PT4126 PT4146 5A 1.5 1.35 1.65 1.225 67.07 43.2 PT4129 5A 1.65 1.49 1.81 1.225 63.9 66.5 PT4127 PT4147 5A 1.8 1.62 1.98 1.225 69.7 110.0 PT4128 PT4148 5A 2.5 2.25 2.75 1.225 64.2 187.0 PT4121 PT4141 5A 3.3 2.95 3.65 1.225 69.3 187.0 For technical support and more information, see inside back cover or visit www.ti.com PT4122 PT4142 4A 5.0 4.5 5.5 2.5 125.2 187.0 PT4125 3.8A 5.2V 4.75 5.75 2.5 134.7 243.0 PT4123 PT4143 1.6A 12.0 10.8 13.2 2.5 139.8 110.0 PT4124 PT4144 1.3A 15.0 13.5 16.5 2.5 137.6 90.9 Application Notes continued PT4120/4140 Series Table 2 DC/DC CONVERTER SERIES ADJUSTMENT RESISTOR VALUES Series Pt # 48V Bus 24V Bus Vo(nom) Va(req’d) 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 1.75 1.8 1.85 1.9 1.95 2.25 2.3 2.35 2.4 2.45 2.5 2.55 2.6 2.65 2.7 2.75 2.95 3.0 3.05 3.1 3.15 3.2 3.25 3.3 3.35 3.4 3.45 3.5 3.55 3.6 3.65 R1 = (Blue) PT4126 PT4146 1.5Vdc PT4127 PT4147 1.8Vdc PT4128 PT4148 2.5Vdc PT4121 PT4141 3.3Vdc PT4122 PT4142 5.0Vdc Va(req’d) (2.8)kΩ (53.2)kΩ (204.0)kΩ 1.3MΩ 627.0kΩ 404.0kΩ 4.5 4.55 4.6 4.65 4.7 4.75 4.8 4.85 4.9 4.95 5.0 5.05 5.1 5.15 5.2 5.25 5.3 5.35 5.4 5.45 5.5 (51.7)kΩ (161.0)kΩ (489.0)kΩ 1.28MΩ 587.0kΩ 355.0kΩ (26.5)kΩ (92.9)kΩ (203.0)kΩ (425.0)kΩ (1.09)MΩ 1.09MΩ 450.0kΩ 237.0kΩ 131.0kΩ 67.7kΩ (90.7)kΩ (146.0)kΩ (224.0)kΩ (341.0)kΩ (536.0)kΩ (926.0)kΩ (2.09)MΩ PT4123 PT4143 12.0Vdc PT4124 PT4144 15.0Vdc Va(req’d) (12.6)kΩ (40.3)kΩ (75.0)kΩ (120.0)kΩ (179.0)kΩ (262.0)kΩ (387.0)kΩ (595.0)kΩ (1.01)MΩ 1.06MΩ 645.0kΩ 437.0kΩ 312.0kΩ 229.0kΩ 169.0kΩ 125.0kΩ 90.2kΩ 62.4kΩ 10.8 11.0 11.2 11.4 11.6 11.8 12.0 12.2 12.4 12.6 12.8 13.0 13.2 13.5 13.6 13.8 14.0 14.2 14.4 14.6 14.8 15.0 15.2 15.4 15.6 15.8 16.0 16.5 (276.0)kΩ (365.0)kΩ (497.0)kΩ (719.0)kΩ (1.16)MΩ 588.0kΩ 239.0kΩ 123.0kΩ 64.6kΩ 29.7kΩ 6.4kΩ (312.0)kΩ (345.0)kΩ (427.0)kΩ (542.0)kΩ (713.0)kΩ (1.0)MΩ (1.57)MΩ 597.0kΩ 253.0kΩ 138.0kΩ 81.0kΩ 46.6kΩ 0.8kΩ 1.19MΩ 502.0kΩ 272.0kΩ 158.0kΩ 88.7kΩ 42.7kΩ 9.9kΩ R2 = Black For technical support and more information, see inside back cover or visit www.ti.com IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third–party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Mailing Address: Texas Instruments Post Office Box 655303 Dallas, Texas 75265 Copyright 2002, Texas Instruments Incorporated