SG5851A Datasheet, PDF (5/12 Pages) Fairchild Semiconductor – Low-Cost, Green-Mode, PWM Controller for Flyback Converters

Electrical Characteristics
VDD=15V, TA=25°C, unless otherwise noted.
Symbol
Parameter
VDD Section
VDD-OP Continuous Operation Voltage
VDD-ON Turn-on Threshold Voltage
VDD-OFF Turn-off Threshold Voltage
IDD-ST Startup Current
IDD-OP Operating Supply Current
VDD-OVP VDD Over-Voltage Protection Level
tD-VDDOVP VDD Over-Voltage Protection Debounce
Feedback Input Section
VFB-OPEN FB Output High Voltage
VFB-OL
tD-OLP
VFB-N
VFB-G
SG
FB Open-loop Trigger Level
Delay Time of FB Pin Open-Loop Protection
Green-Mode Entry FB Voltage
Green-Mode Ending FB Voltage
Green-Mode Modulation Slope
VOZ-OFF FB Threshold Voltage for Zero-Duty
Current-Sense Section
ZSENSE
tPD
VSTHFL
Input Impedance
Delay to Output
Flat Threshold Voltage for Current Limit
VSTHVA
tLEB
DCYSAW
Valley Threshold Voltage for Current Limit
Leading-Edge Blanking Time
Duty Cycle of SAW Limit
Oscillator Section
Center Frequency
fOSC
Hopping Range
tHOP
fOSC-G
fDV
fDT
Hopping Period
Green-Mode Frequency
Frequency Variation vs. VDD Deviation
Frequency Variation vs. Temperature
Deviation
Conditions
Min. Typ. Max. Units
22
V
15.5 16.5 17.5
V
10.5 11.5 12.5
V
VDD=VDD-ON – 0.1V
VDD=15V, GATE with
1nF to GND
9
15
µA
3.0
3.5
mA
Auto Restart
24
25
26
V
Auto Restart
100
µs
RI=95KΩ
5
V
4.3
4.6
4.9
V
56
ms
2.60 2.85 3.10
V
2.2
V
40
70
100 Hz/mV
1.75
V
10
KΩ
VDD=13.5 to 22V
40
55
100
ns
1
V
0.75 0.80 0.85
V
250 310 370
ns
Maximum Duty Cycle
45
%
RI=95KΩ
RI=95KΩ
RI=95KΩ
VDD=13.5 to 22V
TA=-20 to +85°C
65
70
75
KHz
±4.9
3.7
ms
22
KHz
0
0.2
2.0
%
2
%
Continued on the following page…
© 2008 Fairchild Semiconductor Corporation
SG5851A • Rev. 1.0.0
5
www.fairchildsemi.com