SG6846A — Highly Integrated Green-Mode PWM Controller
Frequency
+4.2 KHz
65KHz
-4.2 KHz
PW M
Frequency
+1. 45KHz
22 .5KHz
-1. 45KHz
V
FB-G
V
FB-N
Figure 7. PWM Frequency
V
FB
Electrical Characteristics
(Continued)
V
DD
= 15V and T
A
= 25°C unless otherwise noted.
Symbol
PWM Output Section
DCY
MAX
V
OL
V
OH
t
R
t
F
V
CLAMP
Parameter
Test Condition
Min.
Typ.
Max.
Unit
Maximum Duty Cycle
Output Voltage Low
Output Voltage High
Rising Time
Falling Time
Gate Output Clamping Voltage
(1)
80
V
DD
= 15V, I
O
= 50mA
V
DD
= 12V, I
O
= 50mA
GATE = 1nF
GATE = 1nF
V
DD
= 20V
8
85
90
1.5
%
V
V
350
50
18
ns
ns
V
Over-Temperature Protection (OTP) Section
I
RT
V
RTTH
t
DOTP-LATCH
R
RT-OFF
Output Current of RT Pin
Threshold Voltage for OTP
R
I
= 26kΩ
64
1.015
70
1.065
100
76
1.115
µA
V
ms
Over-Temperature Latch-off Debounce
Equivalent Impedance of RT for OTP
(1)
R
I
= 26kΩ
R
I
= 26kΩ
14
15
16
kΩ
R
I
Section
RI
NOR
RI
MAX
RI
MIN
R
I
Operating Range
Maximum R
I
Value for Protection
Minimum R
I
Value for Protection
13
10
6
36
kΩ
MΩ
kΩ
(1)
Note:
1. The relationship between R
RT-OFF
and R
I
is:
R
RT -OFF
=
V
OTP-LATCH-OFF
/ I
RT
=
V
RT
/ (70
μ
A
×
26 / R
I
(K
Ω
))
© 2008 Fairchild Semiconductor Corporation
SG6846A • Rev. 1.1.4
www.fairchildsemi.com
8
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
