LTC1879 LINER [Linear Technology], LTC1879 Datasheet - Page 3

• Manufacturer Part Number: LTC1879
• Description: 1.2A Synchronous Step-Down Regulator with 15mA Quiescent Current
• Manufacturer: LINER [Linear Technology]

ELECTRICAL CHARACTERISTICS
SYMBOL
V
I
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC1879E is guaranteed to meet specified performance from
0 C to 70 C. Specifications over the – 40 C to 85 C operating ambient
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: T
dissipation P
TYPICAL PERFOR A CE CHARACTERISTICS
The
V
RUN
RUN
IN
300
250
200
150
100
0.7
0.6
0.5
0.4
0.3
0.2
0.1
LTC1879: T
50
= 5V unless otherwise noted.
0
0
–50
–50
DC Supply Current
vs Temperature
R
denotes specifications which apply over the full operating temperature range, otherwise specifications are T
V
DS(ON)
J
IN
is calculated from the ambient temperature T
–25
= 5V
D
SYNCHRONOUS SWITCH
MAIN SWITCH
PARAMETER
RUN Threshold
RUN Input Current
according to the following formula:
J
vs Temperature
= T
V
0
0
TEMPERATURE ( C)
TEMPERATURE ( C)
V
IN
IN
PULSE SKIPPING MODE
Burst Mode OPERATON
A
= 10V
= 10V
+ (P
25
D
50
50
V
140 C/W)
IN
= 5V
75
V
IN
W
= 5V
100
100
1879 G01
1879 G04
U
125
125
CONDITIONS
V
V
A
595
575
555
535
515
495
300
250
200
150
100
RUN
RUN
and power
50
0
–50
0
DC Supply Current
vs Input Voltage
Oscillator Frequency
vs Temperature
Ramping Up
= 0V
V
IN
–25
= 5V
2
0
TEMPERATURE ( C)
INPUT VOLTAGE (V)
PULSE SKIPPING MODE
Burst Mode OPERATION
4
25
Note 4: The LTC1879 is tested in a feedback loop which servos V
balance point for the error amplifier (V
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 6: This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Junction
temperature will exceed 125 C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
50
6
75
8
100
1879 G02
1879 G05
125
10
600
590
580
570
560
550
540
530
520
510
500
0.6
0.4
0.3
0.1
0.5
0.2
0
2
2
Oscillator Frequency
vs Supply Voltage
R
DS(ON)
MIN
0.2
ITH
3
= 1.2V)
4
vs Input Voltage
4
SUPPLY VOLTAGE (V)
SWITCH
INPUT VOLTAGE (V)
MAIN
SYNCHRONOUS
SWITCH
TYP
5
0.7
0.01
A
6
6
= 25 C.
LTC1879
7
MAX
1.5
1
8
8
FB
to the
9
UNITS
1879 G03
1879 G06
3
1879f
10
10
V
A