LTC1771IS8 Linear Technology, LTC1771IS8 Datasheet - Page 3

• Manufacturer Part Number: LTC1771IS8
• Description: IC CTRLR DC/DC STEPDOWN HE 8SOIC
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LTC1771IS8

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.23 ~ 18 V
• Current - Output: 5A
• Voltage - Input: 2.8 ~ 18 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Frequency - Switching: -

SYMBOL
V
I
PGATE t
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: T
dissipation P
Note 3: The LTC1771E is guaranteed to meet performance specifications
from 0 C to 70 C. Specifications over the – 40 C to 85 C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC1771I is guaranteed and tested
over the – 40 C to 85 C operating temperature range.
TYPICAL PERFOR A CE CHARACTERISTICS
ELECTRICAL CHARACTERISTICS
The
V
RUN
RUN/SS
IN
100
LTC1771S8: T
LTC1771MS8: T
90
80
70
60
= 10V, V
2
Efficiency vs Input Voltage
denotes specifications which apply over the full operating temperature range, otherwise specifications are T A = 25 C.
r
, t
J
is calculated from the ambient temperature T
4
f
D
RUN
according to the following formulas:
6
PARAMETER
RUN/SS Pin Threshold
Source Current
PGATE Transition Time (Note 7)
J
INPUT VOLTAGE (V)
= open unless otherwise specified.
= T
8
Rise Time
Fall Time
J
= T
A
10
+ (P
I
A
LOAD
+ (P
12
D
= 1mA
)(110 C/W)
FIGURE 1 CIRCUIT
D
)(150 C/W)
I
14
LOAD
I
LOAD
W
16
= 1A
= 50mA
18
1771 G01
U
20
A
100
and power
90
80
70
60
40
30
20
10
50
0
0.1
CONDITIONS
V
V
C
C
Efficiency vs Load Current
RUN/SS
RUN
LOAD
LOAD
Burst Mode OPERATION
= 0V, V
= 2000pF
= 2000pF
1
Rising
LOAD CURRENT (mA)
ENABLED
Burst Mode OPERATION
DISABLED
IN
= 2.8V to 18V
10
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 5: The LTC1771 is tested in a feedback loop that servos V
balance point for the error amplifier (V
Note 6: No-load supply current consists of sleep mode current (9 A
typical) plus a small switching component necessary to overcome
Schottky diode leakage and feedback resistor current.
Note 7: t
V
FIGURE 1 CIRCUIT
100
IN
= 10V
r
and t
1000
1771 G02
f
are measured at 10% to 90% levels.
– 0.1
– 0.2
– 0.3
– 0.4
0.4
0.3
0.2
0.1
0
0
Line Regulation
MIN
0.5
0.3
FIGURE 1 CIRCUIT
ITH
= 1.23V).
5
TYP
INPUT VOLTAGE (V)
1.0
70
70
1
I
LOAD
I
LOAD
10
= 100mA
LTC1771
MAX
= 1A
140
140
2
3
FB
15
to the
UNITS
1771 G03
3
ns
ns
20
V
A