Datasheet

4
LTC1878
Reference Voltage
vs Temperature
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Oscillator Frequency
vs Temperature
Efficiency vs Output Current
OUTPUT CURRENT (mA)
75
EFFICIENCY (%)
85
95
70
80
90
0.1 10 100 1000
1878 G04
65
1
V
IN
= 3V
V
IN
= 6V
V
IN
= 3.6V
V
IN
= 4.2V
V
OUT
= 1.8V
L = 10µH
TEMPERATURE (°C)
–50
REFERENCE VOLTAGE (V)
0.814
0.809
0.804
0.799
0.794
0.789
0.784
25 75
1878 G05
–25 0
50 100 125
V
IN
= 3.6V
TEMPERATURE (°C)
–50
FREQUENCY (kHz)
605
595
585
575
565
555
545
535
525
515
505
495
10075
1878 G06
–25
0
5025
125
V
IN
= 3.6V
Oscillator Frequency
vs Supply Voltage
SUPPLY VOLTAGE (V)
0
OSCILLATOR FREQUENCY (kHz)
545
535
525
565
555
8
1878 G07
515
505
495
2
4
6
605
595
585
575
LOAD CURRENT (mA)
0
1.77
OUTPUT VOLTAGE (V)
1.78
1.80
1.81
1.82
200
400
500 900
1878 G08
1.79
100 300
600
700
800
1.83
PULSE SKIPPING MODE
V
IN
= 3.6V
L = 10µH
INPUT VOLTAGE (V)
10
R
DS(ON)
(Ω)
0.5
0.6
0.7
5678
1878 G09
0.4
0.3
0
0.1
2
3
4
0.2
0.9
0.8
SYNCHRONOUS
SWITCH
MAIN
SWITCH
Reference Voltage
vs Temperature
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
TEMPERATURE (°C)
–50 –25
0.3
R
DS(ON)
(Ω)
0.4
0.6
0.7
0.8
75 100
1.2
1878 G10
0.5
0 25 50 125
0.9
1.0
1.1
V
IN
= 3V
V
IN
= 5V
SYNCHRONOUS SWITCH
MAIN SWITCH
INPUT VOLTAGE (V)
01
0
DC SUPPLY CURRENT (µA)
100
250
2
4
5
1878 G11
50
200
150
3
6
7
V
OUT
= 1.8V
PULSE SKIPPING
MODE
Burst Mode
OPERATION
TEMPERATURE (°C)
–50
300
250
200
150
100
50
0
25 75
1878 G12
–25 0
50 125100
SUPPLY CURRENT (µA)
PULSE SKIPPING
MODE
Burst Mode
OPERATION
V
IN
= 3.6V