SG6858 Fairchild Semiconductor, SG6858 Datasheet
SG6858
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SG6858 Summary of contents
Page 1
... To protect the external power MOSFET from being damaged by supply over voltage, the output driver is clamped at 17V. SG6858 controllers can improve the performance and reduce the production cost of power supplies. The SG6858 replaces linear and RCC-mode power adapters available in 8-pin DIP and 6-pin SSOT-26 packages ...
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... AC Input Filter N 5 VDD SG6858 FB 2 GND Block Diagram OVP 25V Internal VDD 5(2) BIAS UVLO 16.5V/11.5V SOT(DIP) © 2008 Fairchild Semiconductor Corporation SG6858 • Rev. 1.2.4 Bridge Rectifier Diode Bulk Start VDD + C VDD N A GATE SENSE 4 ...
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... SENSE GND © 2008 Fairchild Semiconductor Corporation SG6858 • Rev. 1.2.4 Figure 3. SSOT-26 Figure 4. DIP-8 GAT VDD SENS E 4 Figure 5. Pin Configurations Totem-pole output driver for the power MOSFET. Power supply. No connection. Current sense. This pin senses the voltage across a resistor. When the voltage reaches the internal threshold, PWM output is disabled ...
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... Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings. Symbol V DC Supply Voltage DD T Operating Ambient Temperature A © 2008 Fairchild Semiconductor Corporation SG6858 • Rev. 1.2.4 Parameter SSOT DIP Human Body Model, JESD22-A114 Machine Model, JESD22-A115 Parameter 4 Min. Max. ...
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... Output Voltage Low GATE-L V Output Voltage High GATE-H t Rising Time R t Falling Time F V Output Clamp Voltage GATE-CLAMP © 2008 Fairchild Semiconductor Corporation SG6858 • Rev. 1.2 unless otherwise specified Test Condition DD-ON V =15V, GATE with DD 1nF to GND R =95kΩ ...
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... Temperature (℃) Figure 8. Startup Current (I Frequenc -40 -25 - Temperature (℃) Figure 10. Frequency (f OSC © 2008 Fairchild Semiconductor Corporation SG6858 • Rev. 1.2 DD-O N 12.5 12.1 11.7 11.3 10.9 10 110 125 ) Figure 7. Turn-Off Threshold Voltage (V DD- Temperature 3.5 3.0 2.5 2.0 1.5 50 ...
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... Figure 12. Green Mode Entry FB Voltage (V vs. Temperature Leading-Edge Blank ing Time (t 350 330 310 290 270 250 -40 -25 - Tem perature (℃) Figure 14. Leading-Edge Blanking Time (t vs. Temperature © 2008 Fairchild Semiconductor Corporation SG6858 • Rev. 1.2.4 (Continued 2.50 2.40 2.30 2.20 2.10 2.00 V =15V DD 1. 110 ...
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... The turn-on and turn-off thresholds are fixed internally at 16.5V/11.5V. During startup, the hold-up capacitor must be charged to 16.5V through the startup resistor, (1) so that the SG6858 is enabled. The hold-up capacitor continues to supply V from the auxiliary winding of the main transformer. V must not drop below 11.5V during this startup process. ...
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... Good placement and layout practices should be followed. Avoiding long PCB traces and component leads, locating compensation and filter components near the SG6858, and increasing the power MOS gate resistance are advised. 9 Duty ...
Page 10
... Transformer - Core: EF-20 - Primary-Side Inductance: 2mH (Pin1 to Pin3 105Turns 18Turns 0.3Φ*2 0.27Φ* 22Turns 0.25Φ*1 2 © 2008 Fairchild Semiconductor Corporation SG6858 • Rev. 1.2.4 Input Voltage Range 90~264V AC IN4007*4 10nF/1KV 22µF/400V Bulk 66kΩ R Start R 47Ω ...
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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 SG6858 • Rev. 1.2.4 Figure 19. 6-Pin, SSOT-6 Package 11 www.fairchildsemi.com ...
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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 SG6858 • Rev. 1.2.4 9.83 9.00 6.67 6.096 3 ...
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... Fairchild Semiconductor Corporation SG6858 • Rev. 1.2.4 13 www.fairchildsemi.com ...