FAN7621 Fairchild Semiconductor, FAN7621 Datasheet
FAN7621
Available stocks
Related parts for FAN7621
FAN7621 Summary of contents
Page 1
... FAN7621SJX © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 Description The FAN7621 is a pulse frequency modulation controller for high-efficiency half-bridge resonant converters. Offering everything necessary to build a reliable and robust resonant converter, the FAN7621 simplifies designs and improves productivity, while improving performance ...
Page 2
... I REF CTC I CTC 2I CTC OLP CON 6 - 0 OLP OVP © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 Cr LVcc CON CTR sense 11.3 / 14. F/F - Time Delay 350ns Counter (1/4) Time ...
Page 3
... No connection This is the low-side gate driving signal connection This pin is the power ground. This pin is connected to the source of the low-side MOSFET. © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 ( (2) CTR (3) HO (4) NC FAN7621 (5) NC (6) CON ( Figure 3 ...
Page 4
... STG Note: 1. The maximum value of the recommended operating junction temperature is limited by thermal shutdown. Thermal Impedance Symbol θ Junction-to-Ambient Thermal Impedance JA © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 =25 ° C unless otherwise specified. A Parameter Pin to Center Voltage 16-DIP 16-SOP (1) (1) Parameter 4 Min ...
Page 5
... Low Level of High-Side Gate Driving V HOL Signal High Level of High-Side Gate Driving V LOH Signal (V -V LVCC LO Low Level of High-Side Gate Driving V LOL Signal © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 Test Conditions CTR Supply Current (HV UV+) - 0.1V CC Supply Current (LV UV =100kHz, V ...
Page 6
... I SU Current Protection Latch Reset LV V PRSET Voltage Dead-Time Control Section D Dead Time T Note: 2. These parameters, although guaranteed, are not tested in production. © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 (Continued) Test Conditions V =4V CON V > 3.5V CON LV > 21V CC (2) (2) (2) ...
Page 7
... Figure 4. Low-Side MOSFET Duty Cycle vs. Temperature 1.1 1.05 1 0.95 0.9 -50 - Temp ( O Figure 6. High-Side V (HV CC 1.1 1.05 1 0.95 0.9 -50 - Temp ( O Figure 8. Low-Side V ( © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 =25ºC. A 1.1 1.05 0.95 0 100 O C) Figure 5. Switching Frequency vs. Temperature 1.1 1.05 1 0.95 0 100 C) ) Start vs. Temperature Figure 7. High-Side V CC 1.1 1.05 1 0.95 0 ...
Page 8
... Figure 10. OLP Delay Current vs. Temperature 1.1 1.05 1 0.95 0.9 -50 - Temp ( O Figure 12. LV OVP Voltage vs. Temperature CC 1.1 1.05 1 0.95 0.9 -50 - Temp ( Figure 14. CON Pin Enable Voltage vs. Temperature © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 (Continued) =25ºC. A 1.1 1.05 1 0.95 0 100 C) Figure 11. OLP Protection Voltage vs. Temperature 1.1 1.05 1 0.95 0 100 C) 1.1 1.05 1 0.95 0.9 ...
Page 9
... Functional Description 1. Basic Operation FAN7621 is designed to drive high-side and low-side MOSFETs complementarily with 50% duty cycle. A fixed dead time of 350ns is introduced between consecutive transitions, as shown in Figure 16. High-side MOSFET gate drive Low-side MOSFET gate drve Figure 16. MOSFETs Gate Drive Signal 2. Internal Oscillator FAN7621 employs a current-controlled oscillator, as shown in Figure 17 ...
Page 10
... The soft-start circuit is made by connecting R-C series network on the R in Figure 19. FAN7621 also has an internal soft-start for 3ms to reduce the current overshoot during the initial cycles, which adds 40kHz to the initial frequency of the external soft-start circuit, as shown in Figure 20. The initial frequency of the soft-start is given as: Ω ...
Page 11
... CC CON F/F 20k Figure 24. Protection Blocks 5.3 Current Sensing Using Resistor : FAN7621 senses drain current as a negative voltage, as shown in Figure 25 and Figure 26. Half-wave sensing allows low power dissipation in the sensing resistor, while full-wave sensing has less switching noise in the sensing signal ...
Page 12
... CC 5.9 Thermal Shutdown (TSD the temperature of the junction exceeds approximately 130 ° C, the thermal shutdown triggers. © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 (OLP) : Overload is 6. Duty imbalance problems may occur due to the radiated noise from main transformer, the inequality of the secondary-side transformer, and so on ...
Page 13
... Typical Application Circuit (Half-Bridge LLC Resonant Converter) Application Device LCD TV FAN7621 Features High efficiency ( >94% at 400V Reduced EMI noise through zero-voltage-switching (ZVS) Enhanced system reliability with various protection functions © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 Input Voltage Range Rated Output Power 390V DC (340~400V ) DC input) DC Figure 29 ...
Page 14
... N 10 → Primary-Side Inductance (L Primary-Side Effective Leakage (L For more detailed information regarding the transformer, visit contact sales@santronics-usa.com © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 (Continued Figure 30. Transformer Construction Wire 0.08φ×88 (Litz Wire) 0.08φ×234 (Litz Wire) 0.08φ ...
Page 15
... 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/. © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 A 19.68 18. ...
Page 16
... 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/. © 2009 Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 Figure 32. 16-Lead Small Outline Package (SOP) 16 www.fairchildsemi.com ...
Page 17
... Fairchild Semiconductor Corporation FAN7621 • Rev. 1.0.3 17 www.fairchildsemi.com ...