Datasheet

5
LT1571 Series
TYPICAL PERFORMANCE CHARACTERISTICS
UW
I
BAT
(A)
0.1
EFFICIENCY (%)
100
98
96
94
92
90
88
86
84
82
80
0.5
0.9 1.51.31.1
1571 G01
0.3 0.7
V
CC
= 15V (EXCLUDING DISSIPATION
ON INPUT DIODE D3)
V
BAT
= 8.4V
JUNCTION TEMPERATURE (°C)
0
REFERENCE VOLTAGE (V)
2.470
2.468
2.466
2.464
2.462
2.460
2.458
25
50 75 100
1571 G02
125 150
SWITCH CURRENT (A)
0 0.2 0.6 1.0 1.4
BOOST CURRENT (mA)
1.6
1571 G03
0.4
0.8
1.2
40
35
30
25
20
15
10
5
0
V
CC
= 16V
V
BOOST
= 26V
(V
X
= 10V)
V
BOOST
= 21V
(V
X
= 5V)
JUNCTION TEMPERATURE (°C)
–20 0 40 80 120
FREQUENCY (kHz)
140
1571 G04
20
60
100
510
505
500
495
205
200
195
190
LT1571-5
LT1571-1, LT1571-2
V
CC
(V)
0
V
REF
(V)
0.003
0.002
0.001
0
0.001
0.002
0.003
5
10 15 20
1571 G05
25 30
ALL TEMPERATURES
I
VA
(mA)
0
V
OVP
(mV)
4
3
2
1
0
0.8
1571 G06
0.20.1 0.3 0.5 0.7 0.9
0.4
0.6
1.0
125°C
25°C
JUNCTION TEMPERATURE (°C)
0
DUTY CYCLE (%)
120
1571 G09
40 80
98
97
96
95
94
93
92
91
90
20 60 100 140
LT1571-1, LT1571-2
(V
X
= 5V)
V
C
(V)
0 0.2 0.6 1.0 1.4 1.8
I
VC
(mA)
1.20
1.08
0.96
0.84
0.72
0.60
0.48
0.36
0.24
0.12
0
0.12
1.6
1571 G08
0.4
0.8
1.2
2.0
V
PROG
(V)
0123
54
I
PROG
(mA)
6
0
–6
1571 G09
125°C
25°C
Efficiency of Figure 4 Circuit
Reference Voltage vs Junction
Temperature Boost Current vs Switch Current
Switching Frequency vs
Temperature
Maximum Duty Cycle
V
REF
Line Regulation V
OVP
vs I
VA
(Voltage Amplifier)
V
C
Pin Characteristic PROG Pin Characteristic