Datasheet

5
LTC1878
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Switch Leakage vs Temperature
TEMPERATURE (°C)
–50
SWITCH LEAKAGE (µA)
25
1878 G13
2.0
1.0
–25 0 50
0.5
0
2.5
1.5
75 100 125
MAIN
SWITCH
V
IN
= 7V
RUN = 0V
SYNCHRONOUS
SWITCH
10µs/DIV
V
IN
= 4.2V
V
OUT
= 1.5V
L = 10µH
C
IN
= 22µF
C
OUT
= 47µF
I
LOAD
= 50mA
SW
5V/DIV
I
L
200mA/DIV
V
OUT
50mV/DIV
AC
COUPLED
1878 G14
Burst Mode OperationSwitch Leakage vs Input Voltage
INPUT VOLTAGE (V)
0
0
SWITCH LEAKAGE (nA)
0.2
0.4
0.6
0.8
24
6
8
1878 G20
1.0
1.2
13
5
7
SYNCHRONOUS
SWITCH
MAIN
SWITCH
RUN = 0V
Pulse Skipping Mode Operation
1µs/DIV
V
IN
= 4.2V
V
OUT
= 1.5V
L = 10µH
C
IN
= 22µF
C
OUT
= 47µF
I
LOAD
= 50mA
SW
5V/DIV
I
L
200mA/DIV
V
OUT
20mV/DIV
AC
COUPLED
1878 G15
40µs/DIV
V
IN
= 3.6V
V
OUT
= 1.5V
L = 10µH
C
IN
= 22µF
C
OUT
= 47µF
I
LOAD
= 500mA
RUN
2V/DIV
I
L
500mA/DIV
V
OUT
1V/DIV
1878 G16
40µs/DIV
V
IN
= 3.6V
V
OUT
= 1.5V
L = 10µH
C
IN
= 22µF
C
OUT
= 47µF
I
LOAD
= 200mA TO 500mA
PULSE SKIPPING MODE
V
OUT
50mV/DIV
AC
COUPLED
I
L
500mA/DIV
I
TH
1V/DIV
1878 G17
Start-Up from Shutdown Load Step Response
Load Step Response
40µs/DIV
V
IN
= 3.6V
V
OUT
= 1.5V
L = 10µH
C
IN
= 22µF
C
OUT
= 47µF
I
LOAD
= 50mA TO 500mA
PULSE SKIPPING MODE
V
OUT
100mV/DIV
AC
COUPLED
I
L
500mA/DIV
I
TH
1V/DIV
1878 G18
Load Step Response
40µs/DIV
V
IN
= 3.6V
V
OUT
= 1.5V
L = 10µH
C
IN
= 22µF
C
OUT
= 47µF
I
LOAD
= 50mA TO 500mA
Burst Mode OPERATION
V
OUT
100mV/DIV
AC
COUPLED
I
L
500mA/DIV
I
TH
1V/DIV
1878 G19