4
LTC3727/LTC3727-1
3727fc
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 LTC3727E/LTC3727E-1 are guaranteed to meet performance
specifications from 0°C to 85°C. Specifications over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3727IG-1 is
guaranteed to meet performance specifications over the –40°C to 85°C
operating temperature range.
Note 3: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formulas:
Efficiency vs Output Current
and Mode (Figure 13)
Efficiency vs Output Current
(Figure 13)
Efficiency vs Input Voltage
(Figure 13)
TYPICAL PERFOR A CE CHARACTERISTICS
UW
OUTPUT CURRENT (A)
0.001
0
EFFICIENCY (%)
10
30
40
50
100
70
0.01
0.1
1
3727 G01
20
80
90
60
10
FORCED
CONTINUOUS
MODE
Burst Mode
OPERATION
V
IN
= 15V
V
OUT
= 8.5V
CONSTANT
FREQUENCY
(BURST DISABLE)
OUTPUT CURRENT (A)
0.001
EFFICIENCY (%)
70
80
10
3727 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
3727 G03
60
50
15
25
35
100
V
OUT
= 5V
I
OUT
= 3A
90
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
LTC3727EG/LTC3727EG-1/LTC3727IG-1: T
J
= T
A
+ (P
D
• 95 °C/W)
LTC3727EUH-1: T
J
= T
A
+ (P
D
• 34 °C/W)
Note 4: The LTC3727/LTC3727-1 are tested in a feedback loop that servos
V
ITH1, 2
to a specified voltage and measures the resultant V
OSENSE1, 2.
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 6: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
Note 7: 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).
R
PLLIN
PLLIN Input Resistance 50 kΩ
I
PLLFLTR
Phase Detector Output Current
Sinking Capability f
PLLIN
< f
OSC
–15 μA
Sourcing Capability f
PLLIN
> f
OSC
15 μA
3.3V Linear Regulator
V
3.3OUT
3.3V Regulator Output Voltage No Load ● 3.25 3.35 3.45 V
V
3.3IL
3.3V Regulator Load Regulation I
3.3
= 0mA to 10mA 0.5 2.5 %
V
3.3VL
3.3V Regulator Line Regulation 6V < V
IN
< 30V (LTC3727) 0.05 0.2 %
6V < V
IN
< 30V (LTC3727-1) 0.05 0.3 %
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 %
