QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK LT3781 and LTC1698 DESCRIPTION Demonstration circuit 479 is an isolated synchronous forward converter featuring the LT3781 and LTC1698 controllers. DC479 is designed to be a board level replacement for "quarter-brick" DC/DC converters. The design can provide 3.3V at 15A from an isolated 48V (36V to 72V) input. Isolation voltage is 1500V DC. The circuit features low input capacitance, over temperature protection, soft start with input undervoltage and overvoltage lockout. Cycling short circuit protection minimizes thermal stress. The output overvoltage circuit provides protection for the load should a fault occur on the sense lines. The standard footprint allows for immediate on board evaluation by plugging directly into the modules’ socket. Design files for this circuit board are available. Call the LTC factory. Table 1. Performance Summary. TA =25°C, VIN =48V, full load, ON/OFF and TRIM pins open, +SENSE shorted to +VOUT, –SENSE shorted to –VOUT, unless otherwise specified. PARAMETER CONDITION Input Voltage Range Maximum Input Current VIN = 36V, Full Load Inrush Transient VIN = 72V MIN TYP MAX 36 48 72 A 0.2 100 Output Voltage Output Regulation V 1.6 Reflected Ripple Current 3.24 3.30 UNITS A2s mAP–P 3.36 V Line 0.1 % Load 0.2 % 15 A Output Current Output Current Limit 18 Output Short Circuit Cycling, Auto-restart Output Ripple and Noise RMS 15 Peak-to-peak (5Hz to 20MHZ) 40 A 1000 Efficiency ms mVRMS 60 88.5 mVP–P % Dynamic Response Peak Deviation 50 100 mV Load Step 50% to 100% Settling Time (to within 10mV of set point) 100 200 µs Output Voltage Trim VTRIM = 3.3V 4 5 6 % VTRIM = 0V –6 –5 –4 % Output Overvoltage On/Off Control 3.65 Logic Low Voltage: Off 0 Logic High Voltage: On 1.0 V 0.6 V V Logic Low Current : Off 0.2 mA Quiescent Current: Off 1.4 mA Start-up Inhibit Period 7.5 ms Turn on Time 10 15 ms 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK PARAMETER CONDITION Thermal Shutdown At RT1 MIN TYP Isolation Capacitance 1500 10 UNITS °C 100 Isolation Voltage Isolation Resistance MAX V DC MΩ 2200 pF OPERATING PRINCIPLES CIRCUIT OVERVIEW This two-transistor forward converter operates at a nominal switching frequency of 240 kHz. Pulse width modulation control is done by U3, the LT3781 synchronous forward controller. Galvanic isolation is met with transformer T1 and optocoupler ISO1. C10 is used as a local bypass to reduce common mode induced current. The main switching power path through T1 is comprised of L1, C2 and C3 as the input filter, with Q1 and Q3 as the primary switches. MOSFETs Q4, 5, 6, and 7 are the secondary synchronous rectifiers. L3 and C4-7 are the secondary output filter. Power is transferred during the on cycle of Q1 and Q3, and integrated by the output filter, just as in a buck regulator. D1 and D2 recover energy stored in the leakage inductance of T1 during the off cycle. The input filter component values for L1, C2 and C3 are optimal and should not be changed without careful evaluation. C1 bypasses the input terminals. For large values of input inductance, an external aluminum electrolytic capacitor will damp the input filter and provide adequate stability. See Linear Technology’s application note AN19 for a discussion on input filter stability analysis. When the primary switches turn off, the transformer voltage reverses, with D1 and D2 conducting to reset the transformer during normal operation. A startup or transient to no load can cause the pulse width modulation to narrow, with insufficient energy to force the reset diodes into conduction. When this occurs, the charge on C20 gets depleted and the top gate drive shuts off. This will result in the converter cycling on and off. To overcome this, Q10 provides a return path to refresh the top gate boost capacitor C20. Feedback control of the output voltage and synchronous drive is done using U1, the LTC1698. The LTC1698 syn- chronizes with the LT3781 via T2, a small pulse transformer. The LTC1698 includes an error amplifier and optocoupler drive buffer, eliminating the output feedforward path associated with ’431 type references. U1 also provides output overvoltage protection. The margin pin allows the output voltage to be adjusted ±5%. During an output short circuit condition, the primary bias supply at Vcc collapses. This results in the converter harmlessly cycling on and off, keeping power dissipation to a minimum. The cycling rate is nominally 1Hz with 48V input. When the short is removed, the converter returns to normal operation. The demo board uses all surface mount devices and will deliver the full rated current at room temperature. With elevated temperature operation, airflow is required for full rated load. The demo board features thermal overload protection. For –48V inputs requiring hot swap capability, the LT4250H negative voltage hot swap controller provides a seamless interface. OPTIONAL FAST START CIRCUIT When power is first applied, Vcc must rise to 15V for the LT3781 to turn on. The bias supply turn on threshold and hysteresis are set internally by U3. R8 and 9 charge the 100µF capacitor C25, and are gated by Q9. With 200Ω resistance, the charge time is 7.5ms at 48V in. The values for R8 and R9 can be adjusted in order to change the turn on delay. Values lower than 100Ω for each resistor will result in abnormally high peak power, and possible component failure. Once the LT3781 turns on, the 5Vref charges C12 causing Q11 to turn off Q9. Bias supply power is delivered through L2 by a winding on T1. In the event of an output short circuit, the voltage on the transformer bias winding collapses. Restart 2 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK time is determined by C12 and R15, and is set to approximately 1 second. The optional fast start circuit can be removed, and a 20kΩ resistor installed for R25. The peak bias supply voltage is self limiting by an internal 18V clamp on the LT3781 Vcc pin. R25 will trickle charge C25, resulting in a turn on delay of approximately 750ms at 48V in. OPTIONAL DIFFERENTIAL SENSE The LT1783 operational amplifier U1 provides true differential remote sense. If this feature is not required the circuit can be removed. To maintain voltage regulation, a zero ohm resistor must be installed for R28. FORWARD CONVERTER DESIGN EQUATIONS The two-transistor forward converter is a good choice for 48V telecom applications. The maximum duty cycle is limited to 50% with the two-transistor forward. This topology is used quite extensively in many modular designs. Unlike the flyback, energy is not intentionally stored in the power transformer. This allows for a much smaller transformer design. The forward converter has pulsating current in the input capacitor, and continuous current in the output capacitor. Worst case ripple current for the input capacitor occurs at 50% duty cycle. Two 0.82µF ceramic capacitors, C2 and C3 are used for the input filter. An aluminum electrolytic type can be substituted as long as it is rated for at least 1.9A RMS. The basic two-transistor synchronous forward converter diagram is shown in Figure 3. The idealized equations for duty cycle relationships are shown below. Basic Duty Cycle Equation: VOUT = VIN • DC • NS NP Input Capacitor RMS Current: IRMS = IOUT • NS • DC − DC NP 2 IRMS = IL(pk −pk) 12 Inductor Ripple Current: IL(pk − pk) = (VOUT+VD)•(1−DC)•fSW L Primary RMS Current: IRMS = IOUT • NS • DC NP Secondary RMS Current: IRMS = IOUT • DC SAFETY AND ISOLATION The demo board is designed to meet the requirements of UL 60950, 3rd edition for basic insulation in secondary circuits. The input is considered to be a TNV-2 circuit, and the output is SELV. The optocoupler and bridging capacitor both have agency file numbers. A 3A fast blow type fuse must be placed in series with the ungrounded (hot) input line. The transformer is designed to meet the basic insulation requirement, with an isolation voltage of 1500VDC. The core is considered to be part of the secondary circuit. As currently built, the transformer uses a class A material insulating system. CONDUCTED EMI Tests for conducted emissions were performed for the demo board. A small external PI filter using a 12µF aluminum electrolytic capacitor, 15µH inductor and 10µF film capacitor allows the converter to meet the CISPR 22 class B limit. No tests for radiated RFI were performed because the radiation is application specific. Proper grounding and layout technique must be observed to minimize radiation. See Figure 4 for test setup. Output Capacitor RMS Current: 3 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK RELIABILITY Reliability prediction for the circuit has been calculated using the Telcordia (formerly Bellcore) SR-332. The black box technique was used. The calculation was made assuming a ground, fixed, controlled environment and quality level II. A 50% electrical stress at 40°C yields an MTBF (mean time between failures) of 1.5 million hours. QUICK START PROCEDURE Demonstration circuit 479 is easy to set up to evaluate the performance of the LT3781 and LTC1698. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: NOTE: When measuring the input or output voltage rip- ple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the Vin or Vout and GND terminals. See Figure 2 for proper scope probe technique. 2. Connect –Sense to –Vout and +Sense to +Vout. The Trim pin should be left floating. 3. Connect the power supply and meters to the Vin pins. 4. Connect the load and meters to the Vout pins. 5. After all connections are made, turn on the input power and verify the output voltage, regulation, ripple voltage, efficiency and other parameters. See Figure 5 to Figure 13 for expected performance. 1. For normal operation, leave the On/Off pin open. Shorting this pin to –Vin will turn off the converter. – + + + + + – – – – + LOAD – Figure 2. Measuring Input or Output Ripple L + + VIN • NP GND VIN Figure 1. Proper Measurement Equipment Setup + + • NS VOUT – – Figure 3. Basic Two-transistor Forward Converter 4 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK SPECTRUM ANALYZER + POWER SUPPLY LISN 50µH 50 + 10µF IN – – + DC479 OUT LOAD – Figure 4. EMI Test Setup 95 90 85 Vin = 36V Vin = 48V 80 Vin = 72V 75 70 0 3 6 9 12 15 LOA D CURRENT (A ) Figure 5. Typical Efficiency 5 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK 80 T1 TRA NSFORM ER 70 Q3 M OSFET L3 INDUCTOR 60 RT1 THERM ISTOR 50 40 30 20 10 0 0 3 6 9 12 15 LOA D CURRENT (A ) Figure 6. Temperature Rise at VIN = 36V, No Airflow 90 80 70 60 50 40 30 T1 TRA NSFORM ER 20 Q3 M OSFET L3 INDUCTOR 10 RT1 THERM ISTOR 0 0 3 6 9 12 15 LOA D CURRENT (A ) Figure 7. Temperature Rise at VIN = 72V, No Airflow 6 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK 90 NO A IRFLOW 80 100 LFM 70 200 LFM 300 LFM 60 400 LFM 50 40 30 20 10 0 0 3 6 9 12 15 LOA D CURRENT (A ) Figure 8. Q3 Temperature Rise at VIN = 48V (Hottest PCB Spot) 90 NO A IRFLOW 80 100 LFM 70 200 LFM 300 LFM 60 400 LFM 50 40 30 20 10 0 0 3 6 9 12 15 LOA D CURRENT (A ) Figure 9. T1 Temperature Rise at VIN = 48V 7 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK 80 NO A IRFLOW 70 100LFM 200 LFM 60 300 LFM 400 LFM 50 40 30 20 10 0 0 3 6 9 12 15 LOA D CURRENT (A ) Figure 10. L3 Temperature Rise at VIN = 48V 70 NO A IRFLOW 60 100 LFM 200 LFM 50 300 LFM 400 LFM 40 30 20 10 0 0 3 6 9 12 15 LOA D CURRENT (A ) Figure 11. RT1 Temperature Rise at VIN = 48V 8 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER—QUARTER BRICK CISP R A "A VG" CISP R B "A VG" CISP R 22 setup (uses 10uF capacito r) 100 80 60 40 20 0 1.E+05 1.E+06 1.E+07 1.E+08 FREQUENCY (Hz) Figure 12. Conducted Emissions at VIN = 48V CISP R A "A VG" CISP R B "A VG" With 12uF, 15uH and 10uF external P I filter 100 80 60 40 20 0 1.E+05 1.E+06 1.E+07 1.E+08 FREQUENCY (Hz) Figure 13. Conducted Emissions at VIN = 48V with External PI Filter 9 VIN DO1608C-332 COILCRAFT R1 10 Q1 Si7456DP Q2 MMBT3906 C3 0.82uF 100V D2 MURS120 D1 MURS120 2 3 Q4 Q5 Si7892DP Si7892DP R5 0.030 C10 2200pF P3 -VIN VCC -VIN D3 BAS21 L2 1.0mH VIN D5 MBR0540 OPT D7 BAT54 R16 2K 1/4W D10 MMBZ5240B 10V -VIN C24 0.1uF 50V + C25 100uF 20V C28 R43 1000pF 10K R45 1.24K 1% R39 52.3K R42 1% 2.43K C32 C31 1% 82pF 1uF 25V SG 12 SENSE 11 9V 4 8 5 50V R32 470 PGND 14 R27 1K R49 OPT C16 1000pF C21 0.1uF 50V R31 C19 0.022uF 1K 0805 15 SYNC C29 0.01uF 10 VC SS SGND 4 SYNC 7 R40 10K VFB 9 R37 3K ISO1 MOC207 43 5VREF 7 5 R46 1K R35 1K C22 4700pF 6 R41 C26 10 3300pF C30 4700pF 1 8 + 3 - 4 5 OPTODRV R21 3.01K 1% -SENSE R22 100 1/4W OPTIONAL DIFFERENTIAL SENSE R28 OPT R34 3.01K 1% -VOUT R33 2.43K 1% VFB 8 OVPIN 9 P6 MARGIN 7 2 C33 0.1uF 50V P5 1% VOUT U2 LTC1698EGN 14 VAUX R14 3.01K 1% R20 3.01K D11 BAT54 OPT -VIN 8 BG 15 3 THERM NC 16 NC 17 RT1 100K D14 BAT54 1 P7 +SENSE 1% GND 5VREF C15 4.7uF R19 3.01K 10 PWRGGD C18 3300pF TG 19 FSET 5 ON/OFF U3 LT3781CG 6 1 SHDN BSTREF 18 2 OVLO 5VREF P2 VBST 20 13 VCC D15 MMBD914 1/4W Q12 FZT690B PULSE ENG. T2 C17 220pF PA0184 D12 BAT54 -VIN 100V 1 R18 100 R23 1K C27 0.1uF 50V C20 0.1uF D13 BAS21 VCC U1 LT1783CS5 16V VCC R26 73.2K 1% C7 330uF 6.3V KEMET + 9V 5 C13 0.22uF 50V VIN R25 OPT C6 330uF 6.3V KEMET + R12 100 1/4W CG 2 VCOMP 6 OPTIONAL FAST START R24 270K 1/4W C11 0 Ohm D6 MBR0540 R17 10K C5 330uF 6.3V KEMET VOUT 2 C14 330pF + -VOUT R10 4.7 R11 62K 1/4W D8 Q11 MMBT3904 MMBZ5248B 18V C12 4.7uF 16V R4 10 1/4W C4 330uF 6.3V KEMET + P4 D4 BAS21 Q10 ZVN3310F R15 47K R3 10 1/4W Q6 Q7 Si7892DP Si7892DP -VOUT VCC 5VREF D9 MMBD914 P8 3.3V@15A +VOUT 250V 4 Q9 FQT7N10L C9 1000pF 100V R6 3.3 ISNSGND 11 FG 16 R9 100 1/4W C8 1000pF 100V Q3 Si7456DP Q8 MMBT3906 VOUT 5 4 R2 10 R8 100 1/4W L3 1.5uH 6 PGND C2 0.82uF 100V 3 C1 0.82uF 100V T1 1 VDD 1 ISNS 12 L1 3.3uH P1 +VIN R38 1K ICOMP 13 R47 1.78K 1% VOUT C23 0.22uF TRIM R48 1.24K 1% NOTES: UNLESS OTHERWISE SPECIFIED 1. TO DISABLE OPTIONAL FAST START: REMOVE C12, D8, D9, R8, R9, R11, R15, Q9, Q11; ADD R25 = 20K. 2. TO DISABLE OPTIONAL DIFFERENTIAL SENSE: REMOVE R12, R14, R19-22, U1; ADD R28 = 0 OHM. 3. ALL RES. ARE IN OHMS. ALL DIODES ARE MMBD914BLT1. ALL NPNs ARE MMBT3904LT1. ALL PNPs ARE MMBT3906LT1. 10 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK 11 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK 12 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK 13 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK APPROVED VENDOR LIST VENDOR AAC (was TAD) AAC (was TAD) AAVID ALLEN BRADLEY AMP APEM API DELEVAN AVX AVX AVX AVX BERG BH ELECTRONICS BI TECHNOLOGIES BI TECHNOLOGIES BOURNS CADDOCK ELECTRONICS CENTRAL SEMI CHICAGO MINIAT. LAMP COILCRAFT COMM CON CONNEX COOPER ELECT. TECH. CORNELL DUBILIER CTS CUI-STACK DALE (see Vishay) DALE (see Vishay) DATA DISPLAY PRODUCT DIODES INC. ELECTRONIC CONCEPTS EPSON FAIRCHILD FAIRCHILD FAIRCHILD FCI FUKUSHIMA FUJI GENERAL SEMICONDUCTOR GOWANDA GRAYHILL HARRIS HEWLETT PACKARD HITACHI PHONE NUMBER (800) 508-1521 (714) 255-9186 (714) 556-2665 (800) 592-4888 (717) 564-0100 (718) 246-1007 (716) 652-3600 (843) 946-0362 (843) 946-0524 (207) 282-5111 (843) 946-0323 (800) 237-2374 (952) 894-9590 (714) 447-2656 (714) 447-2345 (801) 750-7253 (541) 496-0700 (631) 435-1110 (201) 489-8989 (847) 639-6400 (626) 301-4200 (805) 378-6464 (561) 752-5000 (508) 996-8561 (219) 293-7511 (503) 643-4899 (605) 665-1627 (605) 665-9301 (800) 421-6815 (805) 446-4800 (908) 542-7880 (310) 787-6300 (207) 775-4502 (408) 822-2126 (888) 522-5372 (717) 767-8005 (818) 765-8300 (201) 712-0555 (516) 847-3000 (716) 532-2234 (708) 354-1040 (800) 442-7747 (800) 235-0312 (408) 433-1990 PART TYPE WEBSITE ADDRESS CHIP RESISTORS HEAT SINKS CARBON RESISTORS PC MOUNT BNC SMD TOGGLE/PB SWITCH INDUCTORS CHIP CAPS CHIP RESISTORS TANTALUM CAPS HIGH VOLTAGE CAPS CONNECTORS INDUCTORS TRANSFORMERS RES./RES. NETWORKS POTENTIOMETERS, SIPS HIPO. RES., SIPS, DIPS SMALL SIGNAL DISCRETES LEDS INDUCTORS HEADERS, SHUNTS BNC CONNECTORS INDUCTORS CAPACITORS RESISTOR ARRAYS POWER CONNECTORS INDUCTORS SENSE RESISTORS LEDS DIODES 400V FILM CAPACITORS CRYSTALS LOGIC MOSFETS CRG (CUST. RESPONSE) HOT PLUG CONNECTORS MPC RESISTORS SCHOTTKY DIODES DIODES INDUCTORS DIP SWITCHES LOGIC IR LED RF POWER AMPS 14 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK IDT IR IRC ITW PAKTRON JOHNSON COMPONENTS JOHNSON COMPONENTS KEMET KEMET KETEMA KEYSTONE LITEON LTC MAGNETICS MARCON METHODE MF ELECTRONICS MICROCHIP MICRO PLASTICS MICRO-SEMI MIDCOM MIDCOM MILL-MAX MINICIRCUITS MOTOROLA MURATA ELECTRONICS MURATA ELECTRONICS MURATA ELECTRONICS NEC/TOKIN NICHIA NICHICON ON SEMICONDUCTOR ON SHORE PANASONIC PANASONIC PANASONIC PERICOM PHILIPS PHILIPS PHILIPS PULSE QT OPTOELECTRONICS RAYCHEM RG ALLEN RF MICRO DEVICES SAMTEC SANYO SCHOTT (408) 727-6116 (310) 322-3331 (361) 992-7900 (708) 667-3444 (650) 948-6533 (760) 434-5961 (408) 986-0424 (864) 963-6300 (714) 630-0081 (718) 956-8900 (408) 241-4588 (408) 432-1900 (800) 245-3984 (847) 696-2000 (800) 323-6864 (914) 576-6570 (602) 786-7200 (870) 453-8861 (617) 926-0404 (605) 886-4385 (800) 643-2661 (516) 922-6000 (718) 934-4500 (800) 441-2447 (770) 436-1300 (800) 831-9172 (770) 433-5789 (510) 324-4110 (408) 573-0933 (847) 843-7500 (602) 244-6600 (602) 921-3000 (714) 373-7334 (201) 348-5217 (201) 373-7334 (408) 435-0800 (914) 246-2811 (914) 247-2036 (508) 851-2200 (619) 674-8100 (408) 720-1440 (800) 227-4856 (818) 765-8300 (336) 664-1233 (800) 726-8329 (619) 661-6835 (507) 532-3201 LOGIC IC MOSFETS SENSE RESISTORS CAPACITORS RF CONNECTORS RF CONNECTORS TANTALUM CAPS CRG (CUST. RESPONSE) SURGE SUPPRESSORS JACKS, TURRETS LEDS, DIODES HIGH PERF. I.C.S TOROID CORES ETC. HIGH C/V CAPACITORS ZIF SOCKETS CRYSTAL OSCILLATORS MICROCONTROLLER IC NYLON STANDOFFS DIODES INDUCTORS INDUCTORS TURRETS RF TRANSFORMERS LOGIC, REGS CAPS., INDUCTORS, CRG (CUST. RESPONSE) RF DEVICES INDUCTORS/HI C/V CAPS WHITE LEDS ELECTROLYTIC CAPACITOR DISCRETE DIODES ETC. TERMINATORS INDUCTORS, POLY CAPS LEDS SWITCHES LOGIC IC INDUCTORS PLANAR INDUCTORS DISCRETES, I.C.s INDUCTORS RF SWITCH FUSES METAL OXIDE RESISTORS RF2138 / RF2140 WIRE JUMPERS OSCON CAPS INDUCTORS, XFORMERS 15 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK SCHURTER SIGNATRON SIEMENS SILICONIX SILICONIX SPRAGUE SULLINS SUMIDA SUMIDA TAIYO YUDEN TAIYO YUDEN TEKTRONIX TEMIC THERMALLOY THIN FILM TECHNOLOGY TOCOS TOKIN (NEC) TOKO TOSHIBA TOSHIBA UNITED CHEMICON VISHAY VISHAY VITRAMON WIMA ZETEX ZIERICK (707) 778-6311 (909) 464-1883 (108) 257-7910 (800) 554-5565 (408) 988-8000 (207) 324-4140 (760) 744-0125 (847) 956-0667 (408) 982-9660 (408) 573-4150 (800) 348-2496 (800) 835-9433 (408) 970-5700 (972) 243-4321 (507) 625-8445 (847) 884-6664 (510) 324-4110 (847) 699-3430 (714) 455-2000 (949) 455-2000 (847) 696-2000 (605) 665-9301 (605) 665-9301 (203) 268-6261 (914) 347-2474 (631) 366-5068 (800) 882-8020 FUSES AND HOLDERS DB9 CONNECTORS OPTO MOSFETS MOSFETS CAPACITORS HEADERS, SHUNTS INDUCTORS INDUCTORS CHIP CAPS / RES. CRG (CUST. RESPONSE) SCOPE PROBE SOCKETS IR PHOTO DIODE HEAT SINKS THIN FILM CHIP RESISTORS SMD POTENTIOMETERS CAPS., INDUCTORS, RF PRODUCTS SINGLE GATE LOGIC LOGIC ELECTROLYTIC CAPACITOR ZENER/SM. SIGNAL DIODES INDUCTORS, SENSE Rs CERAMIC CHIP CAPACITOR PAPER/FILM CAPACITORS SMALL SIGNAL DISCRETES STAKED PINS 16 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK 17 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK 18 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK 19 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 479 ISOLATED SYNCHRONOUS FORWARD CONVERTER – QUARTER BRICK 20