Product Specification

Low-Cost, Green-Mode PWM Controller for Flyback Converters

SG6858

© System General Corp.

- 5 -

www.sg.com.tw • www.fairchildsemi.com

Version 1.2.1 (IAO33.0045.B2)

September 25, 2007

Feedback Input Section

Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

FB Input to Current Comparator Attenuation

2/5

V/V

Input Impedance

5

KΩ

FB Output High Voltage

4.5

5.0

5.5

V

Green-Mode Entry FB Voltage

2.85

V

Green-Mode Ending FB Voltage

2.20

V

Green-Mode Modulation Slope

75

Hz/mV

Current-Sense Section

Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

Input Impedance

10

kΩ

Delay to Output

60

100

ns

Flat Threshold Voltage for Current Limit

0.96

V

Valley Threshold Voltage for Current Limit

0.75

0.80

0.85

V

Leading-edge Blanking Time

250

300

350

ns

Duty Cycle of SAW Limit

Max. Duty Cycle

45

%

Oscillator Section

Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

Frequency

65

70

75

kHz

Green-Mode Frequency

22

kHz

0

0.02

2.00

%

Frequency Variation vs. Temperature Deviation

2

%

Output Section

Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

Maximum Duty Cycle

70

75

80

%

Output Voltage Low

1.5

V

Output Voltage High

8

V

Rising Time

150

200

250

ns

Falling Time

35

55

75

ns

Output Clamp Voltage

16

17

18

V