SG6846G Fairchild Semiconductor, SG6846G Datasheet - Page 6

• Manufacturer Part Number: SG6846G
• Description: A highly integrated PWM controller, SG6846G provides several features to enhance the performance of flyback converters
• Manufacturer: Fairchild Semiconductor

© 2008 Fairchild Semiconductor Corporation
SG6846G • Rev. 1.0.2
Oscillator Section
Electrical Characteristics
V
DD
Symbol
f
f
V
OSC,MAX
OSC,MIN
f
V
V
t
t
OSC-G
FB-ZDC
f
= 15V and T
hop-1
hop-3
OSC
S
f
f
FB-N
FB-G
DV
DT
G
Normal PWM Frequency
Maximum PWM
Frequency
Minimum PWM Frequency
Jitter Period
Jitter period
Green Mode Minimum Frequency
FB Threshold Voltage for
Frequency Reduction
FB Voltage at f
Slope for Green-Mode Modulation
FB Threshold Voltage for Zero Duty Cycle
Frequency Variation vs. V
Frequency Variation vs. Temperature
Deviation
A
= 25°C unless otherwise noted.
OSC-G
Parameter
(Continued)
DD
Center
Frequency
Jitter Range
Center
Frequency
Jitter Range
Center
Frequency
Jitter Range
Pin, FB Voltage
Jitter Range
Pin, FB Voltage
Jitter Range
Deviation
Figure 5. PWM Frequency
6
R
R
R
R
R
R
R
R
R
V
T
A
DD
Test Condition
I
I
I
I
I
I
I
I
I
= 26kΩ, V
= 13kΩ, V
= 36kΩ, V
= 26kΩ, V
= 26kΩ, V
= 26kΩ
= 26kΩ, V
= 26kΩ, V
= 26kΩ
= -30 to 85°C
= 11.5V to 20V
FB
FB
FB
FB
FB
FB
FB
>V
>V
>V
≥ V
= V
= V
= V
N
N
N
N
G
N
G
±2.54
Min.
44.8
10.2
18.0
1.27
±3.7
±7.4
124
3.9
2.6
3.7
2.1
1.8
62
Continued on following page…
±2.90
Typ.
±4.2
±8.4
47.0
11.5
22.5
1.45
130
4.4
2.8
4.2
2.3
2.0
1.5
65
85
Max.
±3.26
49.2
12.8
25.0
1.62
±4.7
±9.4
136
4.9
4.7
2.5
2.2
5.0
68
3
5
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Hz/mV
Unit
KHz
KHz
kHz
kHz
kHz
kHz
ms
ms
%
%
V
V
V