LTC1877 Linear Technology, LTC1877 Datasheet - Page 5

• Manufacturer Part Number: LTC1877
• Description: High Efficiency Monolithic Synchronous Step-Down Regulator
• Manufacturer: Linear Technology

TYPICAL PERFORMANCE CHARACTERISTICS
1400
1200
1000
800
600
400
200
0
–50
Switch Leakage vs Temperature
V
RUN = 0V
IN
–25
= 10V
AC COUPLED
500mA/DIV
500mA/DIV
50mV/DIV
0
TEMPERATURE ( C)
1V/DIV
5V/DIV
1V/DIV
V
V
RUN
OUT
OUT
I
25
TH
SYNCHRONOUS
I
I
L
L
Load Step Response
V
V
L = 10 H
Start-Up from Shutdown
V
V
L = 10 H
50
IN
OUT
IN
OUT
SWITCH
= 5V
= 5V
MAIN SWITCH
= 1.5V
= 1.5V
75
W
100
10 s/DIV
10 s/DIV
1877 • G12
40 s/DIV
50 s/DIV
U
125
C
C
I
Burst Mode OPERATION
LOAD
IN
OUT
= 10 F
= 47 F
= 50mA TO 500mA
C
C
I
LOAD
IN
OUT
16
14
12
10
8
6
4
2
0
= 10 F
0
= 47 F
Switch Leakage vs Input Voltage
= 500mA
RUN = 0V
1877 • G17
1877 • G15
2
INPUT VOLTAGE (V)
SYNCHRONOUS
4
SWITCH
6
AC COUPLED
AC COUPLED
MAIN SWITCH
500mA/DIV
500mA/DIV
50mV/DIV
50mV/DIV
1V/DIV
1V/DIV
8
V
V
OUT
OUT
I
I
TH
TH
1877 • G13
I
I
L
L
Load Step Response
Load Step Response
V
V
L = 10 H
V
V
L = 10 H
10
IN
OUT
IN
OUT
= 5V
= 5V
AC COUPLED
= 1.5V
= 1.5V
200mA/DIV
20mV/DIV
5V/DIV
V
OUT
SW
I
L
40 s/DIV
20 s/DIV
Burst Mode Operation
V
V
C
C
C
I
PULSE SKIPPING MODE
LOAD
IN
OUT
IN
OUT
IN
C
C
I
PULSE SKIPPING MODE
LOAD
IN
OUT
= 10 F
= 5V
= 10 F
= 10 F
= 47 F
= 1.5V
= 200mA TO 500mA
= 47 F
= 50mA TO 500mA
10 s/DIV
1877 • G16
1877 • G18
LTC1877
L = 10 H
C
I
LOAD
OUT
= 47 F
= 50mA
5
1877 • G14