Datasheet

LTC1877
4
1877fb
TYPICAL PERFORMANCE CHARACTERISTICS
Oscillator Frequency
vs Supply Voltage
Output Voltage vs Load Current
R
DS(ON)
vs Input Voltage
R
DS(ON)
vs Temperature
DC Supply Current vs Input Voltage
DC Supply Current vs Temperature
Effi ciency vs Output Current
Reference Voltage vs Temperature
Oscillator Frequency
vs Temperature
OUTPUT CURRENT (mA)
0.1
EFFICIENCY (%)
10
1000
95
90
85
80
75
70
65
60
55
50
1877 G04
1.0 100
L = 10μH
V
OUT
= 2.5V
V
IN
= 3.6V
V
IN
= 10V
V
IN
= 7.2V
V
IN
= 5V
TEMPERATURE (°C)
–50
REFERENCE VOLTAGE (V)
0.814
0.809
0.804
0.799
0.794
0.789
0.784
25 75
1877 G05
–25 0
50 100 125
V
IN
= 5V
TEMPERATURE (°C)
–50
FREQUENCY (kHz)
605
595
585
575
565
555
545
535
525
515
505
495
10075
1877 G06
–25
0
5025
125
V
IN
= 5V
SUPPLY VOLTAGE (V)
0
OSCILLATOR FREQUENCY (kHz)
605
595
585
575
565
555
545
535
525
515
505
495
1210
1877 G07
2
4
86
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
800
1877 G08
200
400
600
2.53
2.52
2.51
2.50
2.49
2.48
2.47
2.46
2.45
2.44
2.43
PULSE-SKIPPING MODE
V
IN
= 4.2V
L = 10μH
INPUT VOLTAGE (V)
013579
R
DS(ON)
(Ω)
1.2
1.0
0.8
0.6
0.4
0.2
0
2468
1877 G09
10
MAIN SWITCH
SYNCHRONOUS
SWITCH
TEMPERATURE (°C)
–50
R
DS(ON)
(Ω)
1.4
1.2
1.0
0.8
0.6
0.4
0.2
25 75
1877 G10
–25 0
50 100 125
V
IN
= 3V
V
IN
= 5V
SYNCHRONOUS SWITCH
MAIN SWITCH
INPUT VOLTAGE (V)
0
DC SUPPLY CURRENT (μA)
250
200
150
100
50
0
8
1877 G11
2
4
6
10
PULSE-SKIPPING MODE
Burst Mode OPERATION
V
OUT
= 1.8V
TEMPERATURE (°C)
–50
SUPPLY CURRENT (μA)
300
250
200
150
100
50
0
25 75
1877 G11b
–25 0
50 100 125
V
IN
= 5V
PULSE-SKIPPING MODE
Burst Mode OPERATION