LTC3546_15 Datasheet, PDF (4/30 Pages) Linear Technology – Dual Synchronous, 3A/1A or 2A/2A Configurable Step-Down DC/DC Regulator

LTC3546
Electrical Characteristics The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C. V_IN = V_CCA = 3.6V, unless otherwise specified. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
I_SW1D(LKG)
I_SW2A/B(LKG)
V_UVLO
T_PGOOD1
Switch Leakage Current SW1D
Switch Leakage Current SW2A/B
Undervoltage Lockout Threshold
Threshold for Power Good
Percentage Deviation from Regulated V_FB1
(Typically 0.6V).
V_IN = 6V
V_ITH1 = V_ITH2 = 0V
V_RUN1 = V_RUN2 = 0V
V_IN = 6V
V_ITH2 = 0V
V_RUN2 = 0V
V_IN1, V_IN2, V_CCA, V_CCD Rising
V_IN1, V_IN2, V_CCA, V_CCD Falling
V_FB1 Ramping Up, V_SYNC/MODE = 0V
0.01
1
µA
0.01
1
µA
2.03
2.14
2.2
V
1.86
1.97
2.03
V
–8
%
T_PGOOD2
Threshold for Power Good
V_FB2 Ramping Up, V_SYNC/MODE = 0V
Percentage Deviation from Regulated V_FB2
(Typically 0.6V).
–8
%
R_PGOOD1
R_PGOOD2
t_SS
V_RUN1, V_RUN2,
V_PHASE
I_RUN1, I_RUN2,
I_PHASE
VTL_SYNC/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
V_FB from 0% to 95%, V_TRACK/SS Is Floating
V_IN = 6V, V_PHASE = 3V, V_RUN1 = V_RUN2 = 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
VTH_SYNC/MODE SYNC/MODE Threshold Voltage High to
Put the Part into Burst Mode Operation
V_IN – 0.5
V
V_SYNC/MODE
SYNC/MODE Threshold for Clock
Synchronization
0.3
0.8
1.2
V
I_SYNC/MODE
VTH_FREQ
I_BMC1, I_BMC2
SYNC/MODE Leakage Current
FREQ Threshold Voltage High
BMC1, BMC2 Leakage Current
V_IN = 6V, V_SYNC/MODE = 3V
V_IN = 6V, V_BMC = 3V
±0.01
±1
µA
V_IN – 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 LTC3546 is tested under pulsed load conditions such that
T_J ≈ T_A. The LTC3546E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°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 specifications over the full –40°C to 125°C operating
junction temperature range. The maximum ambient temperature
consistent with these specifications is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
impedance and other environmental factors.
Note 3: The LTC3546 is tested in feedback loop which servos V_FB1 to the
midpoint for the error amplifier (V_ITH1 = 0.6V) and V_FB2 to the midpoint for
the error amplifier (V_ITH2 = 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 specified maximum operating junction
temperature may impair device reliability.
Note 7: T_J is calculated from the ambient temperature, T_A, and power
dissipation, P_D, according to the following formula:
T_J = T_A + (P_D • 34°C/W)
Note 8: Minimum current limit is guaranteed by design and correlation to
the R_DS(ON)1D, I_LIM1 and I_LIM2 measurements.
3546fc
4
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