FAN7631 Fairchild Semiconductor, FAN7631 Datasheet
FAN7631
Available stocks
Related parts for FAN7631
FAN7631 Summary of contents
Page 1
... FAN7631SJ FAN7631SJX © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 Description The FAN7631 is a pulse-frequency modulation controller for high-efficiency half-bridge resonant converters that includes a high-side gate drive circuit, an accurate current-controlled oscillator, and various protection functions. The FAN7631 features include variable dead time, operating frequency up to 600kHz, protections such as LUVLO, and a selectable latch or A/R protection using the LS pin for user convenience ...
Page 2
... Application Circuit Diagram Figure 1. Block Diagram © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 Typical Application Circuit (Resonant Half-Bridge Converter) Figure 2. Internal Block Diagram 2 www.fairchildsemi.com ...
Page 3
... This pin is connected to the drain of the low-side MOSFET. Typically, a transformer is connected 14 CTR to this pin This pin is used for the high-side gate-driving signal This pin is used for the supply voltage of the high-side gate-driving circuit. CC © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 Figure 3. Package Pin Assignments (16SOP) Description www.fairchildsemi.com ...
Page 4
... The maximum value of the recommended operating junction temperature is limited by thermal shutdown. Thermal Impedance Symbol θ Junction-to-Ambient Thermal Impedance JA © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 A Parameter at 15V Applied HV to CTR Pin CTR DC CC (2) (2) ...
Page 5
... V Soft-Start Start Voltage SS_START V Soft-Start End Voltage SS_END V Clamped Soft-Start Voltage SSC Initial Output Oscillation Frequency f OSC_SS During Soft-Start V RT-CON Voltage for Startup RT-CON © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 Condition Min CTR HV - 0.1V, V =0V CC,START CTR 0.1V, V =0V CC START ...
Page 6
... Current Latch-Protection Reset Voltage Dead-Time Control Section Dead Time D T Recommended Dead Time Range Note: 3. This parameter, although guaranteed, is not tested in production. © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 (Continued) Condition LV =HV =17V =-40C ~ 130 =17V =-40 ...
Page 7
... Start Voltage vs. Temperature CC 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 -40 - Temperature [ ] Figure 6. HV Start Voltage vs. Temperature CC 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 -40 - Temperature [ ] Figure 8. Pulse Skip Disable Voltage vs. Temperature Figure 9. Pulse Skip Enable Voltage vs. Temperature © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 =25ºC. A 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0. 100 120 Figure 5. 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0. 100 120 Figure 7. 1.20 1.15 1.10 1.05 1.00 ...
Page 8
... Temperature [ ] Figure 12. Output Oscillation Frequency (R vs. Temperature 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 -40 - Temperature [ ] Figure 14. Output Duty Cycle (R vs. Temperature © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 (Continued) =25ºC. A 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0. 100 120 Figure 11. Output Oscillation Frequency ( 100 120 =2.7k) Figure 13. Output Duty Cycle ( ...
Page 9
... Temperature [ ] Figure 18 =2.7k) vs. Temperature OSC_SS T 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 -40 - Temperature [ ] Figure 20. I vs. Temperature OLP © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 (Continued) =25º 100 120 Figure 17 100 120 50 75 100 120 9 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 -40 - 100 Temperature [ ] (R =11.6k) vs. Temperature ...
Page 10
... Temperature [ ] Figure 26. V vs. Temperature FI 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 -40 - Temperature [ ] Figure 28. Dead Time (D =350ns) vs. Temperature T © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 (Continued) =25º 100 120 50 75 100 120 50 75 100 120 Figure 27. Dead Time ( 100 120 10 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 -40 - ...
Page 11
... Figure 29. Current-Controlled Oscillator 2. Gate Driver and Dead Time Programming The FAN7631 employs a gate drive circuit with high driving capability (source: 0.5A / sink: 1A) to cover a wide variety of applications. The two gate drive signals (LO and HO) are complimentary; each signal has 50% duty cycle, including the dead time, as shown in Figure 30. ...
Page 12
... MOSFET’s driving current. Therefore, the resistive-sensing method requires only a small RC filter. The capacitive-sensing method is also available. 4.1. Resistive Sensing Method The FAN7631 can sense the drain current as a negative voltage, as shown in Figure 33 filter with a time constant of 1/30~1/10 of the operating period is typical. Figure 33. Resistive Sensing © ...
Page 13
... Latch Mode protections. Once auto-restart protection is triggered, switching is instantly terminated and the MOSFETs remain off. Then the FAN7631 keeps attempting to restart after the restart delay until the protection situation is removed. When a Latch Mode protection is triggered, the FAN7631 remains ...
Page 14
... Figure 42 shows the internal block diagram for the control (CON) pin and its external configuration. The CON pin is typically connected to the collector terminal of the opto-coupler and the FAN7631 stops switching when the CON pin voltage drops below 0.4V. FAN7631 resumes switching when the CON pin voltage rises above 0 ...
Page 15
... Figure 43 shows the PCB layout guideline to minimize the usage of jumpers. Good PCB layout improves power system efficiency and reliability and minimizes EMI. The Power Ground (PG) and Signal Ground (SG) should meet at a single point. Jumpers should be avoided, especially for the ground trace. © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 Figure 43. PCB Layout Guideline 15 ...
Page 16
... Features High efficiency ( >94% at 400V Reduced EMI noise through zero-voltage-switching (ZVS). Enhanced system reliability with various protection functions. © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 Input Voltage Range 400V (20ms Hold-Up Time) input). DC Figure 44. Typical Application Circuit 16 Output Voltage ...
Page 17
... N 12 → → Primary-Side Inductance ( Primary-Side Effective Leakage (L © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 (Continued 15mm Np Figure 45. Winding Specifications Wire 0.12φ×30 (Litz Wire) 0.1φ×100 (Litz Wire) 0.1φ×100 (Litz Wire) Pin Specification 1-8 630 ...
Page 18
... Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/. © 2011 Fairchild Semiconductor Corporation FAN7631 • 1.0.2 Figure 46. 16-Lead, Small-Outline Package (SOP) 18 www.fairchildsemi.com ...
Page 19
... Fairchild Semiconductor Corporation FAN7631 • 1.0.2 19 www.fairchildsemi.com ...