Datasheet

4
LT1961
1961fa
TYPICAL PERFORMANCE CHARACTERISTICS
UW
FB vs Temperature
Switch On Voltage Drop Oscillator Frequency
SHDN I
P
Current vs Temperature
SHDN Threshold vs Temperature
SHDN Supply Current vs V
IN
TEMPERATURE (°C)
–50
–25 0 25 50 75 100 125
FB VOLTAGE (V)
1961 G01
1.22
1.21
1.20
1.19
1.18
SWITCH CURRENT (A)
0 0.5
1 1.5
SWITCH VOLTAGE (mV)
1961 G02
400
350
300
250
200
150
100
50
0
125°C
25°C
–40°C
TEMPERATURE (°C)
–50
–25 0 25 50 75 100 125
FREQUENCY (MHz)
1961 G03
1.5
1.4
1.3
1.2
1.1
T
A
= 25°C
TEMPERATURE (°C)
–50
–25 0 25 50 75 100 125
SHDN THRESHOLD (V)
1961 G04
1.40
1.38
1.36
1.34
1.32
1.30
V
IN
(V)
0 5 10 15 20 25 30
V
IN
CURRENT (μA)
1961 G05
7
6
5
4
3
2
1
0
T
A
= 25°C
SHDN = 0V
TEMPERATURE (°C)
–50
–25 0 25 50 75 100 125
SHDN INPUT (μA)
1961G06
–12
–10
–8
–6
–4
–2
0
STARTING UP
SHUTTING DOWN
SHDN Supply Current Input Supply Current
Current Limit Foldback
SHUTDOWN VOLTAGE (V)
0
0.2 0.4 0.6 0.8 1 1.2 1.4
V
IN
CURRENT (μA)
1961 G07
300
250
200
150
100
50
0
T
A
= 25°C
V
IN
= 15V
INPUT VOLTAGE (V)
0 5 10 15 20 25 30
V
IN
CURRENT (μA)
1961 G08
1200
1000
800
600
400
200
0
MINIMUM
INPUT
VOLTAGE
T
A
= 25°C
FEEDBACK VOLTAGE (V)
0 0.2
0.4 0.6 0.8 1 1.2
SWITCH PEAK CURRENT (A)
1961 G09
2.0
1.5
1.0
0.5
0
FB INPUT CURRENT (μA)
40
30
20
10
0
FB CURRENT
SWITCH CURRENT
T
A
= 25°C