ltc3728legn-trpbf Linear Technology Corporation, ltc3728legn-trpbf Datasheet - Page 4

• Manufacturer Part Number: ltc3728legn-trpbf
• Description: Dual, 550khz, 2-phase Synchronous Step-down Switching Regulator
• Manufacturer: Linear Technology Corporation

ELECTRICAL CHARACTERISTICS
LTC3728
temperature range, otherwise specifi cations are at T
SYMBOL
V
V
Oscillator and Phase-Locked Loop
f
f
f
R
I
3.3V Linear Regulator
V
V
V
I
PGOOD Output
V
I
V
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
reliabilty and lifetime.
Note 2: T
dissipation P
Note 3: The LTC3728 is tested in a feedback loop that servos V
specifi ed voltage and measures the resultant V
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
4
NOM
LOW
HIGH
PLLFLTR
3.3LEAK
PGOOD
EXTVCC
LDOHYS
3.3OUT
3.3IL
3.3VL
PGL
PG
PLLIN
J
LTC3728: T
is calculated from the ambient temperature T
D
according to the following formulas:
PARAMETER
EXTV
EXTV
Nominal Frequency
Lowest Frequency
Highest Frequency
PLLIN Input Resistance
Phase Detector Output Current
3.3V Regulator Output Voltage
3.3V Regulator Load Regulation
3.3V Regulator Line Regulation
Leakage Current of 3.3V Regulator in
Shutdown
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level, Either Controller
Sinking Capability
Sourcing Capability
J
= T
CC
CC
Switchover Voltage
Hysteresis
A
+ (P
D
• 95 °C/W)
OSENSE1, 2.
A
and power
CONDITIONS
I
V
V
V
f
f
No Load
I
6V < V
V
I
V
V
CC
PLLIN
PLLIN
3.3
PGOOD
A
PLLFLTR
PLLFLTR
PLLFLTR
RUN/SS1, 2
PGOOD
OSENSE
= 25°C. V
V
V
ITH1, 2
= 20mA, EXTV
= 0 to 10mA
OSENSE
OSENSE
< f
> f
IN
= 2mA
= 5V
The
with Respect to Set Output Voltage
OSC
OSC
= 1.2V
= 0V
≥ 2.4V
< 30V
to a
= 0V, V
Ramping Negative
Ramping Positive
l
IN
denotes the specifi cations which apply over the full operating
= 15V, V
CC
IN
Ramping Positive
= 30V
Note 5: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
Note 6: The IC minimum on-time is tested under an ideal condition
without external power FETs. It can be different when the IC is working in
an actual circuit. See Minimum On-Time Considerations in the Application
Information section.
Note 7: The LTC3728E is guaranteed to meet performance specifi cations
from 0°C to 70°C. Specifi cations over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
RUN/SS1, 2
= 5V unless otherwise noted.
l
l
l
3.25
MIN
360
230
480
4.5
–6
6
3.35
0.05
–7.5
TYP
400
260
550
–15
4.7
0.2
0.5
0.1
50
15
10
7.5
MAX UNITS
3.45
–9.5
440
290
590
0.2
0.3
50
±1
9.5
2
3728fd
kHz
kHz
kHz
kΩ
μA
μA
μA
μA
%
%
%
%
V
V
V
V