FDMF8704 Fairchild Semiconductor, FDMF8704 Datasheet
FDMF8704
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FDMF8704 Summary of contents
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... Fairchild Semiconductor Corporation FDMF8704 Rev. G General Description The FDMF8704 is a fully optimized integrated Driver plus MOSFET power stage solution for high current synchronous buck DC-DC applications. The device integrates a driver IC and two Power MOSFETs into a space saving, MLP 8x8, 56-pin package ...
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... VCIN 5 BOOT 21, 40-50, C VSWH 8, 9, 11-20, B VIN 10 TEST PAD 1 22-38 PGND 39 TEST PAD 2 55 DISB 56 PWM FDMF8704 Rev (CGND) (VIN (VSWH Figure 2. MLP 8x8 56L Bottom View IC Ground. Ground return for driver IC. High Side FET Enable. Must be connected to BOOT pin. No connect IC Supply. +5V chip bias power. Bypass with a 1µ ...
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... Control Circuit Supply Current PWM Input High Voltage PWM Input Low Voltage PWM Input Current DISB Input High Voltage DISB Input Low Voltage DISB Input Current Propagation Delay Note 2: t refers to HIGH-to-LOW transition, t PDL(LDRV/HRDV) FDMF8704 Rev 1MHz 100°C sw PCB = 10µs Min. 4.5 7 0.8 . ...
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... Functional Block Diagram VCIN DISB PWM Functional Description The FDMF8704 is a driver plus FET module optimized for synchronous buck converter topology. A single PWM input signal is all that is required to properly drive the high-side and the low-side MOSFETs. Each part is capable of driving speeds up to 1MHz. ...
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... Timing Diagram DISB LDRV / HDRV V IH(PWM) PWM LDRV t HDRV-SW SW FDMF8704 Rev IH(DISB) V IL(DISB) t PDL(DISB) Figure 4. Output Disable Timing V IL(PWM) t PDL(LDRV) 1.2V PDH(HDRV) t PDL(HDRV) t PDH(LDRV) 2.2V Figure 5. Adaptive Gate Drive Timing 5 t PDH(DISB) www.fairchildsemi.com ...
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... Figure 8. Power Loss vs. Switching Frequency 1.15 1.10 1. 12V 1.3V 1.00 OUT I = 30A OUT L = 0.33uH f = 1MHz SW 0.95 4.5 5.0 Driver Supply Voltage, V Figure 10. Power Loss vs. Driver Supply Voltage FDMF8704 Rev 0.33uH 100 125 150 Figure 7. Module Power Loss vs. Output Current 1.15 1.10 1.05 1.00 0.95 6 ...
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... KHz SW Figure 14. Driver Supply Current vs. Frequency 1. CIN 1. 1.80 1. 1.70 1.65 -50 - Temperature, Figure 16. DISB Threshold Voltage vs. Temperature FDMF8704 Rev. G 1.0 V CIN DISB = 5V 0.9 0.8 0.7 0.6 0.5 0.4 0.6 0.8 1.0 -50 Figure 13. Driver Supply Current vs. Temperature 1.83 V CIN 1.81 1.79 1.77 1.75 ...
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... FDMF8704, a local ceramic CIN bypass capacitor is recommended to reduce the noise and to supply the peak current. Use at least a 1µF, X7R or X5R capacitor. Keep this capacitor close to the FDMF8704 V CGND pins. Bootstrap Circuit The bootstrap circuit uses a charge storage capacitor (C and the external schottky diode, as shown in Figure 18 ...
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... Output inductor location should be as close as possible to the FDMF8704 for lower power loss due to copper trace. 4. Snubber for suppressing ringing and spiking of VSWH voltage should be placed near the FDMF8704. The resistor and capacitor need proper size for power dissipation. 5. Place boot diode, ceramic bypass capacitor and boot ...
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... Dimensional Outline and Pad layout FDMF8704 Rev. G (DATUM A) Bayan Lepas FIZ 11900, Penang, Malaysia 10 www.fairchildsemi.com ...
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... TRADEMARKS The following includes registered and unregistered trademarks and service marks, owned by Fairchild Semiconductor and/or its global subsidiaries, and is not intended exhaustive list of all such trademarks. ® ACEx Build it Now™ CorePLUS™ CROSSVOLT™ CTL™ Current Transfer Logic™ ...