Datasheet

LT1952/LT1952-1
4
19521fe
PARAMETER CONDITIONS MIN TYP MAX UNITS
COMP Low Level: V
OL
I
(COMP)
= 250µA 0.15 0.4 V
CURRENT SENSE
I
SENSE
Maximum Threshold COMP = 2.5V, FB = 1V 197 220 243 mV
I
SENSE
Input Current (Duty Cycle = 0%)
I
SENSE
Input Current (Duty Cycle = 80%)
COMP = 2.5V, FB = 1V (Note 4)
COMP = 2.5V, FB = 1V (Note 4)
–8
–35
µA
µA
OC Threshold COMP = 2.5V, FB = 1V 98 107 116 mV
OC Input Current (OC = 100mV) –50 –100 nA
Default Blanking Time COMP = 2.5V, FB = 1V, R
BLANK
= 40k (Note 10) 180 ns
Adjustable Blanking Time COMP = 2.5V, FB = 1V, R
BLANK
= 120k 540 ns
V
BLANK
1 V
SOUT DRIVER
SOUT Clamp Voltage I
(GATE)
= 0µA, COMP = 2.5V, FB = 1V 10.5 12 13.5 V
SOUT Low Level I
(GATE)
= 25mA 0.5 0.75 V
SOUT High Level I
(GATE)
= –25mA, V
IN
= 12V, COMP = 2.5V,
FB = 1V
10 V
SOUT Active Pull-Off in Shutdown V
IN
= 5V, SD_V
SEC
= 0V, SOUT = 1V 1 mA
SOUT to OUT (Rise) DELAY (t
DELAY
) COMP = 2.5V, FB = 1V (Note 10)
R
DELAY
= 120k
40
120
ns
ns
V
DELAY
0.9 V
OUT DRIVER
OUT Rise Time FB = 1V, CL = 1nF (Notes 3, 6) 50 ns
OUT Fall Time FB = 1V, CL = 1nF (Notes 3, 6) 30 ns
OUT Clamp Voltage I
(GATE)
= 0µA, COMP = 2.5V, FB = 1V 11.5 13 14.5 V
OUT Low Level I
(GATE)
= 20mA
I
(GATE)
= 200mA
0.45
1.25
0.75
1.8
V
V
OUT High Level I
(GATE)
= –20mA, V
IN
= 12V, COMP = 2.5V,
FB = 1V
I
(GATE)
= –200mA, V
IN
= 12V, COMP = 2.5V,
FB = 1V
9.9
9.75
V
V
OUT Active Pull-Off in Shutdown V
IN
= 5V, SD_V
SEC
= 0V, OUT = 1V 20 mA
OUT Max Duty Cycle COMP = 2.5V, FB = 1V, R
DELAY
= 10k
(f
OSC
= 200kHz), V
IN
= 10V
SD_V
SEC
= 1.4V, SS_MAXDC = V
REF
83 90 %
OUT Max Duty Cycle Clamp COMP = 2.5V, FB = 1V, R
DELAY
= 10k
(f
OSC
= 200kHz), V
IN
= 10V
SD_V
SEC
= 1.32V, SS_MAXDC = 1.84V
SD_V
SEC
= 2.64V, SS_MAXDC = 1.84V
63.5
25
72
33
80.5
41
%
%
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). COMP = open, FB = 1.4V, R
OSC
= 178k, SYNC = 0V,
SS_MAXDC = V
REF
, V
REF
= 0.1µF, SD_V
SEC
= 2V, BLANK = 121k, DELAY = 121k, I
SENSE
= 0V, OC = 0V, OUT = 1nF, V
IN
= 15V, SOUT =
open, unless otherwise specified.
ELECTRICAL CHARACTERISTICS