Datasheet
4
LTC1628-SYNC
1628syncfa
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formulas:
LTC1628-SYNC: T
J
= T
A
+ (P
D
• 95 °C/W)
Note 3: The LTC1628-SYNC is tested in a feedback loop that servos
V
ITH1,2
to a specified voltage and measures the resultant V
OSENSE1, 2.
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 5: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
Note 6: The minimum on-time condition is specified for an inductor
peak-to-peak ripple current ≥40% of I
MAX
(see minimum on-time
considerations in the Applications Information section).
Efficiency vs Output Current
and Mode (Figure 14)
OUTPUT CURRENT (A)
0.001
0
EFFICIENCY (%)
10
30
40
50
100
70
0.01
0.1
1
1628 G01
20
80
90
60
10
FORCED
CONTINUOUS
MODE
CONSTANT
FREQUENCY
(BURST DISABLE)
Burst Mode
OPERATION
V
IN
= 15V
V
OUT
= 5V
OUTPUT CURRENT (A)
0.001
EFFICIENCY (%)
70
80
10
1628 G02
60
50
0.01
0.1
1
100
90
V
IN
= 10V
V
IN
= 15V
V
IN
= 7V
V
IN
= 20V
V
OUT
= 5V
INPUT VOLTAGE (V)
5
EFFICIENCY (%)
70
80
1628 G03
60
50
15
25
35
100
V
OUT
= 5V
I
OUT
= 3A
90
Efficiency vs Output Current
(Figure 14)
Efficiency vs Input Voltage
(Figure 14)
INTV
CC
and EXTV
CC
Switch
Voltage vs Temperature
Supply Current vs Input Voltage
and Mode (Figure 14)
INPUT VOLTAGE (V)
05
0
SUPPLY CURRENT (µA)
400
1000
10
20
25
1628 G04
200
800
600
15
30
35
BOTH
CONTROLLERS ON
STANDBY
SHUTDOWN
EXTV
CC
Voltage Drop
CURRENT (mA)
0
EXTV
CC
VOLTAGE DROP (mV)
150
200
250
40
1628 G05
100
50
0
10
20
30
50
TEMPERATURE (°C)
–50
INTV
CC
AND EXTV
CC
SWITCH VOLTAGE (V)
4.95
5.00
5.05
25 75
1628 G06
4.90
4.85
–25 0
50 100 125
4.80
4.70
4.75
INTV
CC
VOLTAGE
EXTV
CC
SWITCHOVER THRESHOLD
TYPICAL PERFOR A CE CHARACTERISTICS
UW
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN/SS1, 2
= 5V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
PGOOD Output
V
PGL
PGOOD Voltage Low I
PGOOD
= 2mA 0.1 0.3 V
I
PGOOD
PGOOD Leakage Current V
PGOOD
= 5V ±1 µA
V
PG
PGOOD Trip Level, Either Controller V
OSENSE
with Respect to Set Output Voltage
V
OSENSE
Ramping Negative – 6 –7.5 –9.5 %
V
OSENSE
Ramping Positive 6 7.5 9.5 %