FAN6791 Fairchild Semiconductor, FAN6791 Datasheet - Page 10

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FAN6791

Manufacturer Part Number
FAN6791
Description
The highly integrated FAN6791/3 dual PWM combination controller provides several features to enhance the performance of converters
Manufacturer
Fairchild Semiconductor
Datasheet
© 2008 Fairchild Semiconductor Corporation
FAN6791 / FAN6793 • Rev. 1.0.3
Electrical Characteristics
V
Forward PWM Stage
FBPWM-Feedback Input
IPWM-Current Sense
OPWM-GATE Driver
Soft Start
Notes:
1.
2.
V
DCY
DCY
V
DD
t
Symbol
t
V
OPWM-CLAMP
OPEN-PWM-
OPEN-PWM
ΔV
OPEN-PWM
V
V
HICCUP
OZ-OPWM
=18V; R
V
t
V
When activated, the output is disabled and the latch is turned off.
This is the threshold temperature for enabling the output again and resetting the latch after over-temperature
protection has been activated.
V
Z
LIMIT1
LIMIT2
t
MAX-OFYB
A
BNK
MAX-OPWM
I
R
SLOPE
HGH
t
PD
t
SS
FB
OH
OL
R
F
V
D
I
=24kΩ;T
Maximum Duty Cycle
FB to Current Comparator
Attenuation
Input Impedance
Output High Voltage
PWM Open-Loop Protection
Voltage
Interval of PWM Open-Loop
Protection Reset
PWM Open-Loop Protection
Delay Time
V
Propagation Delay to Output –
V
Peak Current Limit Threshold
Voltage 1
Peak Current Limit Threshold
Voltage 2
Leading-Edge Blanking Time
Slope Compensation
ΔV
ΔV
Added to Current Sense
Output Voltage Maximum
(Clamp)
Output Voltage Low
Output Voltage High
Rising Time
Falling Time
FAN6791 Maximum Duty Cycle
FAN6793 Maximum Duty Cycle
Constant Current Output for
Soft-Start
Discharge Resistance
FBPWM
LIMIT
s
s
=ΔV
: Compensation Voltage
Loop
A
=25°C, unless noted.
for Zero Duty Cycle
SLOPE
Parameter
x (t
on
/t)
FB Pin Open
R
R
V
Drops to 9V
V
V
V
V
V
V
O/P=2V to 9V
V
O/P=9V to 2V
R
R
DD
RMS
RMS
DD
DD
DD
DD
DD
I
I
I
I
=24kΩ
=24kΩ
=24kΩ
=24kΩ
=15V, OPWM
=22V
=15V; I
=13V; I
=15V; C
=15V; C
=1V
=1.5V
Conditions
10
O
O
L
L
=100mA
=100mA
=5nF;
=5nF;
1/3.2
Min.
0.75
0.40
500
270
5.0
4.2
1.2
80
60
30
30
47
60
17
60
4
8
V
LIMIT1
Typ.
1/2.7
0.80
0.45
600
350
470
5.2
4.5
1.3
95
16
60
50
48
65
20
65
5
-0.1
Max.
1/2.2
0.85
0.55
450
700
120
120
120
110
564
4.8
1.4
1.5
70
18
49
70
23
7
www.fairchildsemi.com
Units
V/V
ms
ms
µA
kΩ
ns
ns
ns
ns
%
%
Ω
V
V
V
V
V
V
V
V
V

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