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