Electrical Characteristics (Continued)
TA=25°C unless otherwise specified.
Symbol
Parameter
Test Conditions
Min.
Typ. Max. Unit
UVLO Section
LVCCUV+ LVCC Supply Under-Voltage Positive Going Threshold (LVCC Start)
LVCCUV- LVCC Supply Under-Voltage Negative Going Threshold (LVCC Stop)
11.2
8.9
12.5
10.0
2.50
9.2
13.8
11.1
V
V
V
V
V
V
LVCCUVH LVCC Supply Under-Voltage Hysteresis
HVCCUV+ HVCC Supply Under-Voltage Positive Going Threshold (HVCC Start)
HVCCUV- HVCC Supply Under-Voltage Negative Going Threshold (HVCC Stop)
HVCCUVH HVCC Supply Under-Voltage Hysteresis
8.2
7.8
10.2
9.6
8.7
0.5
Oscillator & Feedback Section
VRT
fOSC
DC
V-I Converter Threshold Voltage
Output Oscillation Frequency
Output Duty Cycle
1.5
94
48
2.0
100
50
2.5
106
52
V
KHz
%
RT=5.2KΩ
fSS=fOSC+40kHz,
RT=5.2KΩ
fSS
tSS
Internal Soft-Start Initial Frequency
Internal Soft-Start Time
140
3
KHz
ms
2
4
Protection Section
VCssH Beginning Voltage to Discharge CSS
0.9
1.0
1.1
V
V
Beginning Voltage to Charge CSS and
Restart
VCssL
0.16
0.20
0.24
VOVP
VAOCP
tBAO
LVCC Over-Voltage Protection
AOCP Threshold Voltage
AOCP Blanking Time(6)
OCP Threshold Voltage
OCP Blanking Time(6)
LVCC > 21V
VCS < VAOCP
VCS < VOCP
21
23
-0.9
50
25
V
V
-1.0
-0.8
ns
V
VOCP
tBO
-0.64
1.0
-0.58
1.5
-0.52
2.0
μs
Delay Time (Low Side) Detecting from
VAOCP to Switch Off(6)
tDA
250
135
400
150
ns
TSD
Thermal Shutdown Temperature(6)
120
°C
Dead-Time Control Section
DT
Dead Time(7)
350
ns
Notes:
6. This parameter, although guaranteed, is not tested in production.
7. These parameters, although guaranteed, are tested only in EDS (wafer test) process.
© 2010 Fairchild Semiconductor Corporation
www.fairchildsemi.com
FSFR-XS Series • Rev.1.0.1
6
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
