LT1308A/LT1308B
TYPICAL PERFORMANCE CHARACTERISTICS
LT1308B
12V Output Efficiency
90
85
80
V
IN
= 5V
SWITCH V
CESAT
(mV)
CURRENT LIMIT (A)
V
IN
= 3.3V
EFFICIENCY (%)
75
70
65
60
55
50
1
100
10
LOAD CURRENT (mA)
1000
1308A/B G04
SHDN Pin Bias Current vs Voltage
50
SHDN PIN CURRENT (μA)
40
BIAS CURRENT (nA)
25°C
85°C
40
30
FB
20
V
REF
(mV)
30
20
10
0
0
2
6
8
4
SHDN PIN VOLTAGE (V)
10
1308 G07
Oscillator Frequency vs
Temperature
800
750
QUIESCENT CURRENT (μA)
700
FREQUENCY (kHz)
650
600
550
500
450
400
–50
–2.5
0
25
50
TEMPERATURE (°C)
75
100
140
130
120
110
100
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1308 • G11
V
FB
(V)
U W
– 40°C
1308 • G10
Switch Current Limit vs
Duty Cycle
4.0
500
Switch Saturation Voltage
vs Current
3.5
400
85°C
300
25°C
–40°C
3.0
200
2.5
100
2.0
0
20
60
40
DUTY CYCLE (%)
80
100
1308 • G05
0
0
1.0
0.5
1.5
SWITCH CURRENT (A)
2.0
1308 G06
FB, LBI Bias Current vs
Temperature
80
70
60
LBI
50
200
199
198
197
196
–25
0
25
50
TEMPERATURE (°C)
75
100
1308 • G08
Low Battery Detector Reference
vs Temperature
203
202
201
10
0
–50
195
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1308 • G09
LT1308A Quiescent Current vs
Temperature
180
170
160
150
Feedback Pin Voltage vs
Temperature
1.25
1.24
1.23
1.22
1.21
1.20
1.19
1.18
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1308 • G12
1308abfa
5
LINER [ LINEAR TECHNOLOGY ]
