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LTC3546 Datasheet, PDF (4/28 Pages) Linear Technology – Dual Synchronous, 3A/1A or 2A/2A Confi gurable Step-Down DC/DC Regulator | |||
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LTC3546
ELECTRICAL CHARACTERISTICS The l denotes the speciï¬cations which apply over the full operating
junction temperature range, otherwise speciï¬cations are at TA = 25°C. VIN = VCCA = 3.6V, unless otherwise speciï¬ed. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
ISW1D(LKG)
ISW2A/B(LKG)
VUVLO
TPGOOD1
Switch Leakage Current SW1D
Switch Leakage Current SW2A/B
Undervoltage Lockout Threshold
Threshold for Power Good
Percentage Deviation from Regulated VFB1
(Typically 0.6V).
VIN = 6V
VITH1 = VITH2 = 0V
VRUN1 = VRUN2 = 0V
VIN = 6V
VITH2 = 0V
VRUN2 = 0V
VIN1, VIN2, VCCA, VCCD Rising
VIN1, VIN2, VCCA, VCCD Falling
VFB1 Ramping Up, VSYNC/MODE = 0V
0.01
1
μA
0.01
1
μA
2.03
2.14
2.2
V
1.86
1.97
2.03
V
â8
%
TPGOOD2
Threshold for Power Good
VFB2 Ramping Up, VSYNC/MODE = 0V
Percentage Deviation from Regulated VFB2
(Typically 0.6V).
â8
%
RPGOOD1
RPGOOD2
tSS
VRUN1, VRUN2,
VPHASE
IRUN1, IRUN2,
IPHASE
VTLSYNC/MODE
Power Good Pull-Down On-Resistance
Power Good Pull-Down On-Resistance
Soft-Start Internal Time.
RUN1, RUN2, and PHASE Threshold
RUN1, RUN2, and PHASE Leakage Current
SYNC/MODE Threshold Voltage Low to Put
the Part into Pulse-Skipping Mode
VFB from 0% to 95%, VTRACK/SS Is Floating
VIN = 6V, VPHASE = 3V, VRUN1 = VRUN2 = 3V
132
300
Ω
132
300
Ω
0.8
1.2
1.9
ms
0.3
0.8
1.2
V
±0.01
±1
μA
0.5
V
VTHSYNC/MODE SYNC/MODE Threshold Voltage High to
Put the Part into Burst Mode Operation
VIN â 0.5
V
VSYNC/MODE SYNC/MODE Threshold for Clock
Synchronization
0.3
0.8
1.2
V
ISYNC/MODE
VTHFREQ
IBMC1, IBMC2
SYNC/MODE Leakage Current
FREQ Threshold Voltage High
BMC1, BMC2 Leakage Current
VIN = 6V, VSYNC/MODE = 3V
VIN = 6V, VBMC = 3V
±0.01
±1
μA
VIN â 0.85
V
±0.4
μA
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 LTC3546E is guaranteed to meet performance speciï¬cations
from 0°C to 85°C. Speciï¬cations over the â40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3546I is guaranteed
to meet performance speciï¬cations over the full â40°C to 125°C operating
junction temperature range
Note 3: The LTC3546 is tested in feedback loop which servos VFB1 to the
midpoint for the error ampliï¬er (VITH1 = 0.6V) and VFB2 to the midpoint for
the error ampliï¬er (VITH2 = 0.6V).
Note 4: Total supply current is higher due to the internal gate charge being
delivered at the switching frequency.
Note 5: Variable frequency operation with resistor is guaranteed by design
and is subject to duty cycle limitations.
Note 6: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the speciï¬ed maximum operating junction
temperature may impair device reliability.
Note 7: TJ is calculated from the ambient temperature, TA, and power
dissipation, PD, according to the following formula:
TJ = TA + (PD ⢠34°C/W)
Note 8: Minimum current limit is guaranteed by design and correlation to
the RDS(ON)1D, ILIM1 and ILIM2 measurements.
3546fb
4
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