LT1952IGN Linear Technology, LT1952IGN Datasheet - Page 4

• Manufacturer Part Number: LT1952IGN
• Description: IC,SMPS CONTROLLER,CURRENT-MODE,SOP,16PIN,PLASTIC
• Manufacturer: Linear Technology

LT1952/LT1952-1
ELECTRICAL CHARACTERISTICS
SOUT DRIVER
SOUT Clamp Voltage
SOUT Low Level
SOUT High Level
SOUT Active Pull-Off in Shutdown
SOUT to OUT (Rise) DELAY (t
V
OUT DRIVER
OUT Rise Time
OUT Fall Time
OUT Clamp Voltage
OUT Low Level
OUT High Level
OUT Active Pull-Off in Shutdown
OUT Max Duty Cycle
OUT Max Duty Cycle Clamp
SOFT-START
SS_MAXDC Low Level: V
SS_MAXDC Soft-Start Reset Threshold
SS_MAXDC Active Threshold
SS_MAXDC Input Current (Soft-Start Pulldown: Idis)
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT1952EGN/LT1952EGN-1 are guaranteed to meet
performance specifications from 0°C to 125°C junction temperature.
Specifications over the –40°C to 125°C operating junction temperature
range are assured by design, characterization and correlation with
statistical process controls. The LT1952IGN/LT1952IGN-1 are guaranteed
over the full –40°C to 125°C operating junction temperature range.
Note 3: Rise and Fall times are measured at 10% and 90% levels.
Note 4: Guaranteed by correlation to static test.
range, otherwise specifications are at T
SD_V
PARAMETER
4
DELAY
SEC
= 2V, BLANK = 121k, DELAY = 121k, I
OL
DELAY
)
A
= 25°C. COMP = open, FB = 1.4V, R
SENSE
= 0V, OC = 0V, OUT = 1nF, V
I
I
I
FB = 1V
V
COMP = 2.5V, FB = 1V (Note 10)
R
FB = 1V, CL = 1nF (Notes 3, 6)
FB = 1V, CL = 1nF (Notes 3, 6)
I
I
I
I
FB = 1V
I
FB = 1V
V
COMP = 2.5V, FB = 1V, R
(f
SD_V
COMP = 2.5V, FB = 1V, R
(f
SD_V
SD_V
I
Measured on SS_MAXDC
FB = 1V, DC > 0%
SS_MAXDC = 1V, SD_V
CONDITIONS
(GATE)
(GATE)
(GATE)
(GATE)
(GATE)
(GATE)
(GATE)
(GATE)
(SS_MAXDC)
IN
IN
DELAY
OSC
OSC
= 5V, SD_V
= 5V, SD_V
= 200kHz), V
SEC
= 200kHz), V
SEC
SEC
= 0µA, COMP = 2.5V, FB = 1V
= 25mA
= –25mA, V
= 0µA, COMP = 2.5V, FB = 1V
= 20mA
= 200mA
= –20mA, V
= –200mA, V
= 120k
The
= 1.4V, SS_MAXDC = V
= 1.32V, SS_MAXDC = 1.84V
= 2.64V, SS_MAXDC = 1.84V
= 150µA, OC = 1V
●
SEC
SEC
denotes the specifications which apply over the full operating temperature
IN
IN
IN
IN
= 0V, SOUT = 1V
= 0V, OUT = 1V
IN
= 10V
= 10V
= 12V, COMP = 2.5V,
= 12V, COMP = 2.5V,
Note 5: Each IC includes over-temperature protection that is intended to
protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when over-temperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 6: Guaranteed but not tested.
Note 7: Maximum recommended SYNC frequency = 500kHz.
Note 8: In applications where the V
network from a SYSTEM V
V
Note 9: V
scaled by x 1.18 (to correlate to worst case V
Note 10: Timing for R = 40k derived from measurement with R = 240k.
= 12V, COMP = 2.5V,
IN ON(MAX)
SEC
OSC
DELAY
DELAY
= 1.4V, OC = 1V
= 178k, SYNC = 0V, SS_MAXDC = V
IN
IN
= 10k
= 10k
= 15V, SOUT = open, unless otherwise specified.
REF
< V
start-up current is measured at V
Z
< 25V should be connected from the V
IN
> 25V, an external zener with clamp voltage
IN
10.5
11.5
9.75
63.5
MIN
pin is supplied via an external RC
9.9
10
20
83
25
1
IN
IN
REF
= V
start-up current at V
0.45
1.25
0.45
TYP
120
800
0.5
0.9
0.2
0.8
40
50
30
72
33
12
13
90
, V
IN ON
REF
IN
– 0.25V and
= 0.1µF,
pin to ground.
MAX
13.5
0.75
14.5
0.75
80.5
1.8
41
IN ON
UNITS
19521fb
mA
mA
µA
ns
ns
ns
ns
).
%
%
%
V
V
V
V
V
V
V
V
V
V
V
V