4
LTC1266
LTC1266 -3.3/LTC1266 -5
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
Q1
V
IN
Pin DC Supply Current (Note 3)
Normal Mode 3.5V < V
IN
< 18V 2.1 3.3 mA
Sleep Mode 3.5V < V
IN
< 18V 170 260 µA
Shutdown V
SHUTDOWN
= 2.1V, 3.5V < V
IN
< 18V 25 60 µA
I
Q2
PWR V
IN
DC Supply Current (Note 3)
Normal Mode 3.5V < PWR V
IN
< 18V 20 50 µA
Sleep Mode 3.5V < PWR V
IN
< 18V 1 7 µA
Shutdown V
SHUTDOWN
= 2.1V, 3.5V < PWR V
IN
< 18V 1 7 µA
V
SENSE1
Current Sense Threshold V
BINH
= 0V
(Burst Mode Operation Enabled)
LTC1266CS, LTC1266IS V
SENSE
–
= 3.3V, V
FB
= V
OUT
/2.64 + 25mV (Forced) 25 mV
LTC1266CS V
SENSE
–
= 3.3V, V
FB
= V
OUT
/2.64 – 25mV (Forced) 135 155 180 mV
LTC1266IS V
SENSE
–
= 3.3V, V
FB
= V
OUT
/2.64 – 25mV (Forced) 135 155 190 mV
LTC1266-3.3, LTC1266-5 (I and C) V
SENSE
–
= V
OUT
+ 100mV (Forced) 25 mV
LTC1266CS-3.3, LTC1266CS-5 V
SENSE
–
= V
OUT
– 100mV (Forced) 135 155 180 mV
LTC1266IS-3.3, LTC1266IS-5 V
SENSE
–
= V
OUT
– 100mV (Forced) 135 155 190 mV
V
SENSE2
Current Sense Threshold V
BINH
= 2.1V
(Burst Mode Operation Disabled)
LTC1266CS, LTC1266IS V
SENSE
–
3.3V, V
FB
= V
OUT
/2.64 + 25mV (Forced) –20 mV
LTC1266CS V
SENSE
–
3.3V, V
FB
= V
OUT
/2.64 – 25mV (Forced) 130 155 185 mV
LTC1266IS V
SENSE
–
3.3V, V
FB
= V
OUT
/2.64 – 25mV (Forced) 130 155 195 mV
LTC1266-3.3, LTC1266-5 (I and C) V
SENSE
–
= V
OUT
+ 100mV (Forced) –20 mV
LTC1266CS-3.3, LTC1266CS-5 V
SENSE
–
= V
OUT
– 100mV (Forced) 130 155 185 mV
LTC1266IS-3.3, LTC1266IS-5 V
SENSE
–
= V
OUT
– 100mV (Forced) 130 155 195 mV
V
SHDN
Shutdown Pin Threshold C Grade 0.55 0.8 2 V
I Grade 0.50 0.8 2 V
t
OFF
Off-Time (Note 4) C
T
= 390pF, I
LOAD
= 700mA, C Grade 3.8 5 6.5 µs
C
T
= 390pF, I
LOAD
= 700mA, I Grade 3.8 5 7.0 µs
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
T
J
= T
A
+ (P
D
× 110°C/W)
Note 3: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 4: In applications where R
SENSE
is placed at ground potential, the off-
time increases approximately 40%.
Note 5: The LTC1266CS, LTC1266CS-3.3, LTC1266-5 and LTC1266ACS
are not tested and not quality assurance sampled at –40°C and 85°C.
These specifications are guaranteed by design and/or correlation. The
LTC1266IS, LTC1266IS-3.3, LTC1266IS-5 and LTC1266AIS are
guaranteed and tested over the –40°C to 85°C operating temperature
range.
Note 6: Unless otherwise noted the specifications for the LTC1266A are
the same as those for the LTC1266.
Note 7: t
r
and t
f
are measured at 10% and 90% levels.
–40°C < T
A
< 85°C (Note 5), V
IN
= 10V, unless otherwise noted.
ELECTRICAL CHARACTERISTICS