LT1935
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Undervoltage Lockout
FB Pin Voltage
Oscillator Frequency
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
1.28
1.27
1.26
1.25
1.24
2.4
2.3
2.2
2.1
2.0
1.9
1.8
–25
0
25
50
75
125
–25
0
25
50
75
125
–50
100
–50
100
50
TEMPERATURE (°C)
100 125
–50 –25
0
25
75
TEMPERATURE (°C)
TEMPERATURE (°C)
1935 G02
1935 G01
1935 G03
Peak Switch Current vs SHDN Pin
Voltage (Soft-Start)
Current Limit
Switch Saturation Voltage
4
3
2
1
0
400
300
200
100
0
4
3
2
1
0
50% DUTY CYCLE
A
T
= 25°C
A
T
= 25°C
TYP
MIN
T
= 85°C
A
T
= 25°C
A
0
0.5
1.0
1.5
2.0
2.5
3.0
1.0
1.5
0
2.0
0.5
0
20
40
60
80
100
SWITCH CURRENT (A)
SHDN VOLTAGE (V)
DUTY CYCLE (%)
1935 G05
1935 G06
1935 G04
SHDN Pin Current
Frequency Foldback
80
60
40
20
0
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
T
= 25°C
T
= 25°C
A
A
4
8
10 12 14
SHDN PIN VOLTAGE (V)
0
0.2
1.2 1.4
0
2
6
16
0.4 0.6 0.8 1.0
FEEDBACK VOLTAGE (V)
1935 G07
1935 G08
1935f
3
Linear Systems [ Linear Systems ]
