PT4441 TI | Alldatasheet

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Technical content

Features

  • 36V to 75V Input Voltage Range
  • Programmable Output Voltage Range: 1.3V to 3.5V
  • -40° to +85°C Ambient
  • 1500 VDC Isolation
  • 89% Efficiency
  • On/Off Inhibit
  • Differential Remote Sense
  • N+1 Current Sharing SLTS024C (Revised 6/20/2002)

Description

The PT4481 Excalibur™ DC/DC converter module combines state-of-the- art power conversion technology with un-paralleled flexibility. Incorporating high efficiency and ultra-fast transient response, these modules provide up to 30A of output current over the program- mable voltage range of 1.3V to 3.5V. This represents a full 100W output at 3.3V. The modules include a number of inbuilt features to facilitate system integration. These include a foldback output current limit, over-temperature protection, and an inhibit on/off control. A differential remote sense is also provided to compensate for voltage drop between the converter and load. For applications requiring power supply redundancy, multiple PT4481 modules may connected for operation in an ‘N+1’ configuration. Each PT4481 connected will share the load current with other active PT4481 modules.

  • Over-Current Protection
  • Over-Temperature Protection
  • Over-Voltage Protection
  • Space-Saving Package
  • Solderable Copper Case
  • Safety Approvals: UL 60950 CSA 22.2 950 VDE EN60950 Pending L O A D PT4481 +V sns +V out -V out -Vsns 8-13 14-19 202522 2423 VID0 - VID4 +V in –V in InhibitC 1 PROGRAMMING PINS +V OUT +V IN –V IN –V OUT C o C 2
  • C o = Optional 330µF electrolytic capacitor
  • C 1 = Optional 33µF, 100V electrolytic capacitor
  • C 2 = Optional 1µF, 100V ceramic capacitor
  • Programming pins, VID0–VID4, are shown configured for Vo =3.3V
  • For normal operation, pin 3 (Inhibit) must be connected to –Vin.
  • For details on additional N+1 components consult the related application note.

Ordering Information

PT4481/G6F = 1.3 to 3.5 Volts PT Series Suffix (PT1234x) Case/Pin Order Package Configuration Suffix Code * Vertical N (EKD) Horizontal A (EKA) SMD C (EKC) * Previously known as package styles 1200, 1210, and 1215. (Reference the applicable package code draw- ing for the dimensions and PC board layout) Pin-Out Information Pin Function 1+ V in 2– V in

3 Inhibit

4 Do not connect

5 Do not connect

6 Sync †

7 (+)Remote Sense 8+V out 9+ V out 10 +V out 11 +V out 12 +V out 13 +V out Pin Function 14 –V out 15 –V out 16 –V out 17 –V out 18–V out 19 –V out 20 (–)Remote Sense

21 VID0

22 VID1

23 VID2

24 VID3

25 VID4

26 Share †

PT4481—48V 100-W 30-A Programmable Isolated DC/DC Converter † Pins 6 & 26 are used for N+1 configuration (see related application note). For stand-alone operation, leave open circuit.

  • Shaded functions indicate those pins that are referenced to primary-side potential.

For technical support and more information, see inside back cover or visit www.ti.com PT4480 Series Comparison Output Voltage Configuration for Functionality Program Range Current Sharing PT4481 Regulator 1.3V– 3.5V N+1 with other PT4481s PT4482 Regulator 1.3V– 3.5V With PT4499 boosters PT4499 PT4482 Booster N/A Used only with PT4482 PT4483 Regulator 4.6V–5.7V N+1 with other PT4483s PT4484 Regulator 4.6V–5.7V With PT4498 boosters PT4498 PT4484 Booster N/A Used only with PT4484 PT4485 Regulator 6.5V– 17.5V N+1 with other PT4485s PT4486 Regulator 6.5V–17.5V With PT4497 boosters PT4497 PT4486 Booster N/A Used only with PT4486 PT4481— 48V 100-W 30-A Programmable Isolated DC/DC Converter Programming Information VID4=1 VID4=0 VID3 VID2 VID1 VID0 Vout Vout 1 1 1 1 2.0V 1.30V 1 1 1 0 2.1V 1.35V 1 1 0 1 2.2V 1.40V 1 1 0 0 2.3V 1.45V 1 0 1 1 2.4V 1.50V 1 0 1 0 2.5V 1.55V 1 0 0 1 2.6V 1.60V 1 0 0 0 2.7V 1.65V 0 1 1 1 2.8V 1.70V 0 1 1 0 2.9V 1.75V 0 1 0 1 3.0V 1.80V 0 1 0 0 3.1V 1.85V 0 0 1 1 3.2V 1.90V 0 0 1 0 3.3V 1.95V 0 0 0 1 3.4V 2.00V 0 0 0 0 3.5V 2.05V Logic 0 = Connect to (–)Remote Sense, pin 20 Logic 1 = Open circuit (no pull-up resistors) VID3 & VID4 must not be changed while unit is operating # This specification covers only the PT4481 regulator. Specifications (Unless otherwise stated, T a =25°C, Vin =48V, Vo =3.3V, Co =0µF, and Io =Iomax) PT4481 Characteristic Symbol Conditions Min Typ Max Units Output Current I o Over Vin range 0 — 30 A Input Voltage Range V in Over Io Range 36 4875 VDC Set Point Voltage Tolerance V o tol — ±1 ±1.5 %V o Temperature Variation Reg temp –40° ≤Tcase ≤ +100°C, Io =0 — ±0.5 — %V o Line Regulation Reg line Over Vin range — ±0.1 ±1 %V o Load Regulation Reg load Over Io range — ±0.2 ±1 %V o Total Output Voltage Variation ∆Votot Includes set-point, line, load, —± 2± 3% V o–40° ≤Tcase ≤ +100°C Efficiency η Io =15A V o =3.3V — 89 — Vo =2.5V — 87 — % Vo =1.5V — 81 — Vo Ripple (pk-pk) V r 20MHz bandwidth V o >2V — 60 75 mVppVo ≤2V — 45 55 Transient Response t tr 0.1A/µs load step, 50% to 75% Iomax — N/A — µs ∆Vtr Vo over/undershoot — 1 — %V o 1A/µs load step, 50% to 100% Iomax — 75 — µs Vo over/undershoot — ±5 — %V o Current Limit I lim Vin =36V, ∆Vo = –1% —3 5—Afoldback continuous limit Current Share Tolerance I shr tol With other PT4481 modules in N+1 — ±10 — % Over-Voltage Protection OVP Shutdown and latch off — 125 — %V o Switching Frequency ƒ s Over Vin range 270 300 350 kHz Under-Voltage Lockout UVLO — 34.5 — V Inhibit (Pin 3) Referenced to –V in (pin 2) Input High Voltage V IH 2.5 — Open (1) V Input Low Voltage VIL –0.5 — +0.8 Input Low Current IIL — –0.2 — mA Standby Input Current I in standby pins 3 & 2 connected — 4 10 mA Internal Input Capacitance C in —3 —µ F External Output Capacitance C out Between +Vo and –Vo 0 — 10,000 µF Isolation Voltage Input–output/input–case 1500 — — V Capacitance Input to output — 1100 — pF Resistance Input to output 10 — — M Ω Operating Temperature Range T c Case temperature, over Vin range -40 — +115 (2) °C Over-Temperature Shutdown OTP Case temperature, auto reset — 120 — °C Storage Temperature T s — -40 — +125 °C Reliability MTBF Per Bellcore TR-332 1.4 — — 10 6 Hrs50% stress, Ta =40°C, ground benign Mechanical Shock — Per Mil-Std-883D, method 2002.3, — 500 — G’s 1mS, half-sine, mounted to a fixture Mechanical Vibration — Mil-Std-883D, Method 2007.2 Suffixes A, C — 20 (3) —G ’ s 20-2000Hz, pcb mounted Weight — — — 90 — grams Flammability — Materials meet UL 94V-0 Notes: (1) The Inhibit (pin 3) has an internal pull-up, which if left open circuit allows the converter to operate when input power is applied. The open-circuit is limited to 6.5V. Refer to the application notes for interface considerations. (2) See Safe Operating Area curves or contact the factory for the appropriate derating. (3) The case pins on through-hole pin configuration (suffix A) must be soldered. For more information see the applicable package outline drawing.

For technical support and more information, see inside back cover or visit www.ti.com 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 Efficiency vs Output Current Ripple vs Output Current Power Dissipation vs Output Current Typical CharacteristicsPT4481— 48V 100-W 30-A Programmable Isolated DC/DC Converter Stand Alone, No Heatsink Safe Operating Area, Vin =48V (See Note B)Performance Characteristics, Vo =3.3V (See Note A) 0 5 10 15 20 25 30 Iout (A ) Ambient Temperature (°C) 500LFM 400LFM 300LFM 200LFM 100LFM Nat conv Airflow 100 0 5 10 15 20 25 30 Iout (A ) Efficiency - % 48.0V 75.0V 36.0V VIN 100 0 5 10 15 20 25 30 Iout (A ) Ripple - mV 75.0V 48.0V 36.0V VIN 0 5 10 15 20 25 30 Iout (A ) Pd - Watts 36.0V 75.0V 48.0V VIN

For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT4481 Configuring PT4481 DC/DC Converters for N+1 Operation ‘N+1’ vs OR’ing The PT4481 DC/DC converter modules may be operated with other PT4481 modules in ‘N+1’ configurations. A simple OR’ing connection allows a number of converters to share the load current. An ‘N+1’ configuration adds redundancy by employing at least one more converter than is necessary to supply the load. This ensures that upon the loss of one converter, sufficient capacity remains to supply the load without interruption. As an example, a 45-A load configured for ‘N+1’ would require no less than three PT4481 converters. Two are needed to meet the load demand, plus one additional converter to ensure redundancy. Figure 1-1 shows the schematic for operating two PT4481 converters in an ‘N+1’ configuration for a 25-A load application. Blocking Diodes A true ‘N+1’ redundant system must also protect the output bus against fault current back-feeding a con- verter. Without a blocking diode, a converter will sink current as a result of a fault at its output, or due to the loss of its input source. The blocking diodes 4, (D1 PT4481 PT4481 8–13 REMOTE SENSE (+) REMOTE SENSE ( –) PROGRAMMING PINS C OUT , 330µF (Required) 18 –13 14–19 25 24 23 22 21 14–19 62 6 2062 6 REMOTE SENSE (+) 2122232425 PROGRAMMING PINS D 2, OR'ing Diode (Required) –VIN +V IN 25-A LOAD Inhibit –VOUT +V OUT +V IN –V IN +V OUT –V OUT VID4 – VID0 +Sns –SnsShareSyncInhibit –SnsShareSyncInhibit +Sns +V IN –V IN +V OUT –V OUT VID4 – VID0 C IN C IN D 1, OR'ing Diode (Required) C OUT , 330µF (Required) Figure 1-1; Connection Schematic for Operation in Parallel/N+1 Configuration & D2 in Figure 1-1), protect against reverse current flow under such conditions. Notes 1. For ‘N+1’ redundancy, always use one more converter than is required to supply the load. 2. The VID pins for all converter modules must be independently set to the same voltage program code. 3. All converters connected for ‘N+1’ operation must be located on the same printed circuit board. A similar footprint and trace layout for each converter will facilitate current sharing.

4 A number of high-current rectifier diodes are

available with a low forward voltage drop. They are specifically designed for OR’ing applications in ‘N+1’ systems. Eg. The 82CNQ030, and MBRB2515. 5. As a result of excess capacity and the losses in the blocking diodes, system efficiency is reduced. 6. The interconnection of pin 6 (Sync), and pin 26 (Share) between all modules are required for load current sharing and operation at a common frequency.

For technical support and more information, see inside back cover or visit www.ti.com Operating Features of the PT4470 and PT4480 Series of Isolated DC/DC Converters Under-Voltage Lockout An Under-Voltage Lock-Out (UVLO) inhibits the operation of the converter until the input voltage is above the UVLO threshold (see the applicable data sheet specification). Below this voltage, the module’s output is held off, irrespective of the state of the Inhibit control (pin 3). If the Inhibit control is connected to –V in (pin 2), the module will automatically power up when the input voltage rises above the UVLO threshold. The UVLO allows the module to produce a clean transition during both power-up and power-down, even when the input voltage is rising or falling slowly. It also reduces the high start-up current during normal power-up of the converter, and minimizes the current drain from the input source during low-input voltage conditions. The UVLO threshold includes about 2V of hysteresis. Once operational, the con verter will conform to its operating specifications when the minimum specified input voltage is reached. Over-Current Protection To protect against load faults, the PT4470/80 series of DC/DC converters incorporate an output current limit. Once the load current drawn from the module reaches the current limit threshold, any attempt by the load to draw additional current will result in a significant drop in the module’s regulated output voltage. The current limit circuitry incorporates a limited amount of foldback. This has the effect of slightly reducing the output current from the module when supplying an absolute short circuit. Upon removal of the load fault, the output voltage from the converter will automatically recover to its programmed regulation voltage. Output Over-Voltage Protection The PT4470/80 series of DC/DC converters incorporate circuitry that continually senses the output for an over- voltage (OV) condition. The OV threshold automatically tracks the VID output voltage program setting to a level 25% higher than that programmed at the control pins, VID0 through VID4. If the converter output voltage exceeds the OV threshold, the converter is immediately shut down and remains in a latched-off state. To resume normal operation the converter must be actively reset. This is accomplished by either cycling the status of the Inhibit control (pin 3) from “On” to “Off” and then back “On” again, or by momentarily removing the input power to the converter. For failsafe operation and redundancy, the OV protection uses circuitry that is independent of the converter’s internal feedback loop. Over-Temperature Protection Over-temperature protection is provided by an internal temperature sensor, which closely monitors the tempera- ture of the converter’s metal case. If the case temperature exceeds the specified limit (see applicable data sheet), the converter will shut down. The converter will then automatically restart when the sensed temperature drops by about 10°C. When operated outside its recommended thermal derating envelope (see data sheet SOA curves), the converter will typcially cycle on and off at intervals from a few seconds to one or two minutes. This is to ensure that the internal components are not permanently damaged from excessive thermal stress. Primary-Secondary Isolation Electrical isolation is provided between the input terminals (primary) and the output terminals (secondary). All con- verters are production tested to a primary-secondary withstand voltage of 1500VDC. This specification com- plies with UL60950 and EN60950 and the requirements for operational isolation. Operational isolation allows these converters to be configured for either a positive or negative input voltage source. The data sheet ‘Pin-Out Information’ uses shading to indicate which pins are associated with the primary. They include pins 1 through 5, inclusive. Fuse Recommendations If desired, an input fuse may be added to protect against the application of a reverse input voltage. Thermal Considerations Airflow may be necessary to ensure that the module can supply the desired load current in environments with elevated ambient temperatures. The required airflow rate may be determined from the Safe Operating Area (SOA) thermal derating chart (see converter specifica- tions). The recommended direction for airflow is into the longest side of the module’s metal case. See Figure 1. Recommended direction for airflow is into (perpendicular to) the longest side. Figure 1 PT4470, PT4480 Series

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