Datasheet
LT1308A/LT1308B
3
1308abfb
The l denotes the specifi cations which apply over the full operating temperature
range, otherwise specifi cations are at T
A
= 25°C. Commercial Grade 0°C to 70°C. V
IN
= 1.1V, V
SHDN
= V
IN
, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
Q
Quiescent Current Not Switching, LT1308A
Switching, LT1308B
V
SHDN
= 0V (LT1308A/LT1308B)
140
2.5
0.01
240
4
1
µA
mA
µA
V
FB
Feedback Voltage
l
1.20 1.22 1.24 V
I
B
FB Pin Bias Current (Note 3)
l
27 80 nA
Reference Line Regulation 1.1V ≤ V
IN
≤ 2V
2V ≤ V
IN
≤ 10V
l
0.03
0.01
0.4
0.2
%/V
%/V
Minimum Input Voltage 0.92 1 V
g
m
Error Amp Transconductance ∆I = 5µA 60 µmhos
A
V
Error Amp Voltage Gain 100 V/V
f
OSC
Switching Frequency V
IN
= 1.2V
l
500 600 700 kHz
Maximum Duty Cycle
l
82 90 %
Switch Current Limit Duty Cycle = 30% (Note 4) 2 3 4.5 A
Switch V
CESAT
I
SW
= 2A (25°C, 0°C), V
IN
= 1.5V
I
SW
= 2A (70°C), V
IN
= 1.5V
290
330
350
400
mV
mV
Burst Mode Operation Switch Current Limit
(LT1308A)
V
IN
= 2.5V, Circuit of Figure 1 400 mA
Shutdown Pin Current V
SHDN
= 1.1V
V
SHDN
= 6V
V
SHDN
= 0V
l
l
l
2
20
0.01
5
35
0.1
µA
µA
µA
LBI Threshold Voltage
l
196
194
200
200
204
206
mV
mV
LBO Output Low I
SINK
= 50µA
l
0.1 0.25 V
LBO Leakage Current V
LBI
= 250mV, V
LBO
= 5V
l
0.01 0.1 µA
LBI Input Bias Current (Note 5) V
LBI
= 150mV 33 100 nA
Low-Battery Detector Gain 3000 V/V
Switch Leakage Current V
SW
= 5V
l
0.01 10 µA
The l denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at T
A
= 25°C.
Industrial Grade –40°C to 85°C. V
IN
= 1.2V, V
SHDN
= V
IN
, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
Q
Quiescent Current Not Switching, LT1308A
Switching, LT1308B
V
SHDN
= 0V (LT1308A/LT1308B)
l
l
l
140
2.5
0.01
240
4
1
µA
mA
µA
V
FB
Feedback Voltage
l
1.19 1.22 1.25 V
I
B
FB Pin Bias Current (Note 3)
l
27 80 nA
Reference Line Regulation 1.1V ≤ V
IN
≤ 2V
2V ≤ V
IN
≤ 10V
l
l
0.05
0.01
0.4
0.2
%/V
%/V
Minimum Input Voltage 0.92 1 V
g
m
Error Amp Transconductance ∆I = 5µA 60 µmhos
A
V
Error Amp Voltage Gain 100 V/V