Datasheet

3
LT1317/LT1317B
E
LECTR
IC
AL C CHARA TERIST
ICS
Commercial Grade V
IN
= 2V, V
SHDN
= 2V, T
A
= 25°C unless otherwise noted.
Industrial Grade V
IN
= 2V, V
SHDN
= 2V, –40°C ≤ T
A
≤ 85°C unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
Q
Quiescent Current Not Switching, V
SHDN
= 2V (LT1317) ● 160 µA
V
SHDN
= 0V (LT1317/LT1317B) ● 40 µA
V
SHDN
= 2V, Switching (LT1317B) ● 7.5 mA
V
FB
Feedback Voltage ● 1.20 1.26 V
I
B
FB Pin Bias Current (Note 2) ● 80 nA
Input Voltage Range ● 1.7 12 V
g
m
Error Amp Transconductance ∆I = 5µA ● 70 140 240 µmhos
Maximum Duty Cycle ● 80 %
Switch Current Limit (Note 3) V
IN
= 2.5V, Duty Cycle = 30% ● 550 1350 mA
f
OSC
Switching Frequency ● 500 750 kHz
Shutdown Pin Current V
SHDN
= V
IN
● 0.1 µA
V
SHDN
= 0V ● –7 µA
LBI Threshold Voltage ● 180 220 mV
LBO Output Low I
SINK
= 10µA ● 0.25 V
LBO Leakage Current V
LBI
= 250mV, V
LBO
= 5V ● 0.1 µA
LBI Input Bias Current (Note 4) V
LBI
= 150mV ● 60 nA
Switch Leakage Current V
SW
= 5V ● 3 µA
Switch V
CE
Sat I
SW
= 500mA ● 400 mV
Reference Line Regulation 1.8V ≤ V
IN
≤ 12V ● 0.15 %/V
SHDN Input Voltage High ● 1.4 6 V
SHDN Input Voltage Low ● 0.4 V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Shutdown Pin Current V
SHDN
= V
IN
● 0.015 0.06 µA
V
SHDN
= 0V ● –2.3 –6 µA
LBI Threshold Voltage 190 200 210 mV
● 180 200 220 mV
LBO Output Low I
SINK
= 10µA ● 0.15 0.25 V
LBO Leakage Current V
LBI
= 250mV, V
LBO
= 5V ● 0.02 0.1 µA
LBI Input Bias Current (Note 4) V
LBI
= 150mV ● 540nA
Low-Battery Detector Gain 1MΩ Load 2000 V/V
Switch Leakage Current V
SW
= 5V ● 0.01 3 µA
Switch V
CE
Sat I
SW
= 500mA 300 350 mV
● 400 mV
Reference Line Regulation 1.8V ≤ V
IN
≤ 12V ● 0.08 0.15 %/V
SHDN Input Voltage High ● 1.4 6 V
SHDN Input Voltage Low ● 0.4 V
Note 2: Bias current flows into FB pin.
Note 3: Switch current limit guaranteed by design and/or correlation to
static tests. Duty cycle affects current limit due to ramp generator.
Note 4: Bias current flows out of LBI pin.
The ● denotes specifications which apply over the full operating
temperature range.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.