AHF2815T SERIES HYBRID-HIGH RELIABILITY DC/DC CONVERTER. 28V Input, Triple Output. Description AHF. Features /10/07 PD A

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1 PD A HYBRID-HIGH RELIABILITY DC/DC CONERTER AHF285T SERIES 28 Input, Triple Output Description The AHF285T Series of DC/DC converters provide 8 of power and an extended temperature range for use in military and industrial applications. Designed to the nominal input requirements of MIL-STD-704, these devices have nominal 28DC inputs with +5 and ±5 triple outputs to satisfy a wide range of requirements. The basic circuit utilizes a pulse width modulated, feed forward topology at a nominal switching frequency of 550KHz. Input to output isolation is achieved through the use of transformers in the forward and feedback circuits. The proprietary magnetic feedback circuit provides for an extremely wide bandwidth control loop with a high phase margin. The closed loop frequency response of this converter family extends to approximately 50KHz, resulting in superior line and load transient characteristics. This feedback method is also inherently temperature and radiation insensitive. This gives the AHF Series an important advantage over converters that incorporate optocouplers in their design. Manufactured in a facility qualified to MIL-PRF-38534, these converters are fabricated utilizing DSCC qualified processes. For available screening options, refer to device screening table in the data sheet. ariations in electrical, mechanical and screening can be accommodated. Contact IR Santa Clara for special requirements. Features AHF 6 to 40DC Input Range (28DC Nominal) 5, ±5 Output Infinite Short Circuit and Overload Protection 8 Output Power Fast Loop Response for Superior Transient Characteristics Operating Temperature Range from -55 C to +25 C Available Popular Industry Standard Pin-Out Resistance Seam elded Case for Superior Long Term Hermeticity Efficiency Up to 75% Shutdown from External Signal 400,000 Hour MTBF at 85% Constant Switching Frequency (550KHz Nominal) Standard Microcircuit Drawing Available 0/0/07

2 Specifications T CASE = -55 C to +25 C, IN = +28 ± 5% unless otherwise specified 7 Typical Characteristics Conversion frequency 550KHz Temperature Range Recommended Operating temperature -55 C to +25 C Storage case temperature -65 C to +35 C Test Symbol Conditions -55 C Tc +25 C in = 28 dc ±5%, C L = 0 unless otherwise specified 7 STATIC CHARACTERISTICS Output voltage OUT I OUT = 0 (main) TC = 25 C Current,2,3 Ripple oltage,4 Power,2,3 REGULATION Line,3 I OUT RIP P OUT R LINE I OUT = 0 (dual) IN = 6, 28, and 40 dc (main) IN = 6, 28, and 40 dc (dual) IN = 6, 28, and 40 dc B = DC to 2 MHz (main) IN = 6, 28, and 40 DC B = DC to 2 MHz (dual) IN = 6, 28, and 40 dc (main) (+dual) (-dual) (total) IN = 6, 28, and 40 DC I OUT = 20, 600,200 ma (main) I OUT = 0, ±33.4, ±66.7 ma (dual) Load,3 R LOAD IN = 6, 28, and 40 DC I OUT = 20, 600, 200mA (main) I OUT = 0, ±33.4, ±66.7 ma (dual) Input current I IN I OUT = 0, inhibit (pin ) tied to input return (pin 7) Ripple current 4 I RIP I OUT = 200mA (main) I OUT = ±66.7 ma (dual) B = DC to 2MHz TC = 25 C T C = 25 C AHF285T Limits Min ±4.50 ± Max ±5.50 ± ± ±35 ±75 Unit ma ma m p-p m p-p m 50 ±75 5 ma I OUT = 0, inhibit (pin ) = open 50 ma 50 ma p-p P Overload, T = ±25 C 5 Efficiency E FF P OUT = Full load T C = ±25 C 68 % Isolation ISO Input to output or any pin to case (except pin 6) at 500 dc Tc = +25 C T C = ±25 C 00 MΩ Load fault power T C = ±25 C 8.0 dissipation 3 D C Short Circuit, T C = ±25 C 6.0 Switching frequency F S KHz Inhibit Open OI Circuit oltage eight 35 g For Notes to Specifications, refer to page 3 2

3 Notes to Specifications. Tested at each output. 2. Parameter guaranteed by line and load regulation tests. 3. At least 20percent of the total output power should be taken from the (+5.0 volt) main output. 4. Bandwidth guaranteed by design. Tested for 20KHz to 2.0MHz. 5. An overload is that condition with a load in excess of the rated load but less than that necessary to trigger the short circuit protection and is the condition of maximum power dissipation. 6. Above 25 C case temperature, derate output power linearly to 0 at 35 C case. 7. T CASE = -55 C to 85 C for non screened grade. Block Diagram 2 +out +Input 8 EMI Filter Filter & Regulator Case 6 Inhibit Input Primary Housekeeping Supply Drive Pulse idth FB Modulator CS Error Amp & Ref 4 -out out Output Return Input Return 7 Application Information Inhibit Function Connecting the inhibit input (Pin ) to input common (Pin 7) will cause the converter to shut down. It is recommended that the inhibit pin be driven by an open collector device capable of sinking at least 400µA of current. The open circuit voltage of the inhibit input is.5 ±.0DC. Thermal Management Assuming that there is no forced air flow, the package temperature rise above ambient ( T) may be calculated using the following expression: T = 80 A 0.7 p 0.85 ( C) where A = the effective surface area in square inhes (including heat sink if used), P = power dissipation in watts. The total surface area of the AHF package is 4.9 square inches. If a worse case full load efficiency of 75% is assumed, then the case temperature rise can be calculated as follows: P = POUT = 8 = Eff.78 T = 80 (4.9) -0.7 (2.66) 0.85 = 60.4 C Hence, if T AMBIENT = +25 C, the DC/DC converter case temperature will be approximately 85 C if no heat sink or air flow is provided. Standard Microcircuit Drawing Equivalence Table Standard Microcircuit endor Cage IR Standard Drawing Number Code Part Number AHF285T 3

4 Mechanical Outlines dia., 8 pins (0.760) Standard (5.2) (36.83).05 (28.07) (22.99) (7.9) (2.83) (20.32).20 (28.45) R Typ (2.290) (6.600) (8.380) MAX Flanged Pin Designation Pin # Designation Inhibit Input 2 + Dual Output 3 +5 Output Return 4 - Dual Output 5 +5 Output 6 Case Ground 7 Input Return 8 +Input 4

5 Device Screening Requirement MIL-STD-883 Method No Suffix ES 2 HB CH Temperature Range -20 C to +85 C -55 C to +25 C 3-55 C to +25 C -55 C to +25 C Element Evaluation MIL-PRF Class H Non-Destructive Bond Pull Internal isual Temperature Cycle 00 Cond B Cond C Cond C Constant Acceleration 200, Y Axis 500 Gs 3000 Gs 3000 Gs PIND 2020 Burn-In hrs@hi temp 60 hrs@25 C 60 hrs@25 C Final Electrical MIL-PRF C 25 C 2-55 C, +25 C, -55 C, +25 C, ( Group A ) & Specification +25 C +25 C PDA MIL-PRF % Seal, Fine and Gross 04 Cond A Cond A, C Cond A, C Cond A, C Radiographic 202 External isual 2009 Notes: Best commercial practice 2 Sample tests at low and high temperatures 3-55 C to +05 C for AHE, ATO, AT Model Input oltage Nominal 28 = 28 Output oltage 5 = 5,±5 Part Numbering AHF 28 5 T F /CH Screening Level (Please refer to Screening Table) No Suffix, ES, HB, CH Package Options F = Flange Blank = Non-Flanged Output T = Triple ORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, Tel: (30) IR SANTA CLARA: 2270 Martin Av., Santa Clara, California 95050, Tel: (408) isit us at for sales contact information. Data and specifications subject to change without notice. 0/