LTC1773 LINER [Linear Technology], LTC1773 Datasheet - Page 3

• Manufacturer Part Number: LTC1773
• Description: Synchronous Step-Down DC/DC Controller
• Manufacturer: LINER [Linear Technology]

ELECTRICAL CHARACTERISTICS
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LTC1773 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.
TYPICAL PERFOR A CE CHARACTERISTICS
– 0.05
– 0.10
– 0.15
– 0.20
– 0.25
– 0.30
100
90
80
70
60
50
0
1
0
Efficiency vs Load Current
Load Regulation
V
V
SEE FIGURE 1
IN
OUT
0.5
= 5V
Burst Mode
OPERATION
= 2.5V
SYNC(750kHz)
OUTPUT CURRENT (mA)
10
1.0
LOAD CURRENT (A)
1.5
FORCED CONTINUOUS
100
2.0
R
SENSE
SEE FIGURE 1
2.5
W
= 0.025Ω
1000 5000
3.0
1773 G01
1773 G16
U
3.5
100
400
350
300
250
200
150
100
50
90
80
70
60
50
0
0
1
Efficiency vs Load Current
V
vs Load Current
R
V
Si9801DY
V
SEE FIGURE 1
IN
OUT
SENSE
OUT
-V
= 1.8V
OUT
= 2.5V
500
= 0.025Ω
10
OUTPUT CURRENT (mA)
Dropout Voltage
LOAD CURRENT (mA)
V
IN
1000
= 8V
V
100
Note 3: T
P
Note 4: The LTC1773 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: Rise and fall times are measured using 10% and 90% levels.
IN
D
= 5V
1500
V
according to the following formula:
IN
= 3.3V
J
1000
is calculated from the ambient temperature T
LTC1773: T
2000
1773 G02
1773 G05
10,000
2500
J
= T
A
+ (P
100
500
450
400
350
300
250
200
150
100
95
90
85
80
75
50
0
D
2
2
Efficiency vs Input Voltage
Input and Shutdown Currents
vs Input Voltage
• 120°C/W)
V
SEE FIGURE 1
V
Si9801DY
R
L = CDRH6D28-3RO
OUT
OUT
SENSE
ITH
= 2.5V
= 1.8V
= 0.8V)
= 0.025Ω
4
4
I
INPUT VOLTAGE (V)
OUT
INPUT VOLTAGE (V)
SYNC TO 750kHz
Burst Mode OPERATION
I
= 100mA
SHUTDOWN
OUT
LTC1773
A
= 1A
6
6
and power dissipation
8
8
FB
1773 G03
1773 G06
to the
1773fb
3
10
10