Datasheet

LTC3731
6
3731fc
TYPICAL PERFORMANCE CHARACTERISTICS
Reference Voltage
vs Temperature
Error Amplifier g
m
vs Temperature
Maximum I
SENSE
Threshold
vs Temperature
Oscillator Frequency
vs Temperature Operating Frequency vs V
PLLFLTR
Undervoltage Reset Voltage
vs Temperature
Efficiency vs I
OUT
(Figure 14) Efficiency vs V
IN
(Figure 14) Efficiency vs Frequency (Figure 14)
EFFICIENCY (%)
0.1
LOAD CURRENT (A)
100
90
80
70
60
50
40
30
20
10
0
1 10 100
3731 G01
V
IN
= 8V
V
OUT
= 1.5V
V
FCB
= OPEN
V
FCB
= 5V
V
FCB
= 0V
V
IN
(V)
0
EFFICIENCY (%)
100
95
90
85
80
75
70
65
60
55
50
20
3731 G02
5
10
15
25
I
L
= 45A
I
L
= 15A
V
OUT
= 1.5V
f = 250kHz
FREQUENCY (kHz)
200
EFFICIENCY (%)
100
95
90
85
80
75
600
3731 G03
300
400
500
I
LOAD
= 20A
V
OUT
= 1.5V
V
IN
= 20V
V
IN
= 12V
V
IN
= 8V
V
IN
= 5V
TEMPERATURE (°C)
–50
REFERENCE VOLTAGE (mV)
3731 G04
0 25 50 75
610
605
600
595
590
–25 125100
TEMPERATURE (°C)
4.0
ERROR AMPLIFIER g
m
(mmho)
4.5
5.5
6.0
3731 G05
5.0
–50 0 25 50 75–25 125100
–50 0 25 50 75–25 125100
TEMPERATURE (°C)
3731 G06
MAXIMUM I
SENSE
THRESHOLD (mV)
85
80
75
70
65
V
O
= 1.75V
V
O
= 0.6V
–50 0 25 50 75–25 125100
TEMPERATURE (°C)
FREQUENCY (kHz)
700
600
500
400
300
200
100
0
3731 G07
V
PLLFLTR
= 2.4V
V
PLLFLTR
= 1.2V
V
PLLFLTR
= 0V
V
PLLFLTR
= 5V
PLLFLTR PIN VOLTAGE (V)
0
OPERATING FREQUENCY (kHz)
700
600
500
400
300
200
0.5 1 1.5 2 2.5
3731 G08
–50 0 25 50 75–25 125100
TEMPERATURE (°C)
3731 G09
0
UNDERVOLTAGE RESET (V)
1
3
4
5
2