SG6846B Fairchild Semiconductor, SG6846B Datasheet
SG6846B
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SG6846B Summary of contents
Page 1
... PWM pulses out. This FB green-mode function enables power supplies to meet international power conservation requirements. The SG6846B is designed for SMPS with surge-current output incorporated with a two-level OCP function. Besides, the cycle-by-cycle current limiting, if the switching current is higher than OCP threshold and ...
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... AC input Filter N VIN Block Diagram 0.9V/0.7V VIN 3 V -TH-G DD VDD 7 UVLO 16.5V/10.5V 23. 1.05V © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3 VDD GATE 8 SENSE 6 GND SG6846B Figure 1. Typical Application Over Power Compersation 0.895-0.065 Internal BIAS ...
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... Marking Information SG6846BFTP XXXXXXXXYWWV ※ Marking for SG6846BLSZ (Pb-free) SG6846BCSZ (Pb-free) ※ Marking for SG6846BLSY (Green-compound) SG6846BCSY (Green-compound) © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3 OCP Latch OCP auto-recovery SOP Lead Free + ROHS Compatible Null = regular package XXXXXXXX: Wafer Lot Y: Year ...
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... The sensed voltage is used for peak-current-mode control and cycle-by-cycle current limiting. If the switching current is higher than OCP threshold and lasts for 200ms, SG6846B turns off immediately. This two-level OCP feature is especially suitable for SMPS with surge current output open-circuit failure occurs in the feedback loop, the internal protection circuit disables PWM output as long as V The totem-pole output driver for the power MOSFET ...
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... The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings. Symbol T Operating Ambient Temperature A © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 Parameter <50°C SOP A SOP Parameter 5 Min ...
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... STH3V-2/3 t Delay Time for Over-Current Protection D-OCP t Output Short Circuit Protection delay time D-Short t SS-65KHz Period During Soft Start Time t SS-130KHz © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 Test Condition for Short-Circuit DD V – 0.16V DD-ON GATE Open R = 26kΩ ...
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... Frequency Variation vs Frequency Variation vs. Temperature f DT Deviation © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3 Timing = 200ms OCP Figure 6. SG6846B OCP/SCP Logic Flow Diagram (Continued) Test Condition Center Frequency R = 26kΩ Jitter Range Center Frequency R = 13kΩ Jitter Range ...
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... Operating Range NOR I RI Maximum R Value for Protection MAX I RI Minimum R Value for Protection MIN I Note: 1. The relationship between R © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 (Continued) Test Condition V = 15V 12V GATE = 1nF GATE = 1nF V = 20V DD ( 26kΩ ...
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... Temperature (℃ ) Figure 11. OCP Threshold Voltage for Current Limit (V ) vs. Temperature STH1V-2/3 © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3 Temperature DD- Figure 8 ...
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... Temperature PW M Turn-on Threshold Voltage (V 0.925 0.920 0.915 0.910 0.905 -40 -25 - Temperature ( ℃ ) Figure 17. PWM Turn-on Threshold Voltage (V vs. Temperature © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 (Continued Temperature OSC 8 7.2 8 7.0 8 6.8 8 6.6 8 6 110 125 - Figure 14 ...
Page 11
... Over-Temperature Protection (OTP) An external NTC thermistor can be connected from the RT pin to GND. The impedance of the NTC decreases at high temperatures. When the voltage of the RT pin drops below 1.05V, the SG6846B is turned off. For protection-mode options, see Ordering Information. the resistance and the switching ...
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... Good placement and layout practices should be followed. Avoid long PCB traces and component leads. Compensation and filter components should be located near the SG6846B. © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 (Continued) Slope compensation 12 Figure 19 ...
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... R6 330Ω +/-1% R19 102KΩ +/-1% R14 0Ω22 +/-5% R16, R17 1W 20Ω +/-5% R11 20KΩ +/-5% R12 100KΩ +/-5% R20 887KΩ +/-1% R22 10KΩ +/-1% © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 BD1 LF2 CX2 R12 ...
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... 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/. © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 5.00 4.80 A 3.81 ...
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... Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 15 www.fairchildsemi.com ...