LTC3890-2 Datasheet, PDF (5/40 Pages) Linear Technology – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller

LTC3890-2
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 = 12V, V_RUN1,2 = 5V, EXTV_CC = 0V unless otherwise noted.
(Note 2)
SYMBOL PARAMETER
PGOOD1 and PGOOD2 Outputs
V_PGL
I_PGOOD
V_PG
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
t_PG
Delay for Reporting a Fault
CONDITIONS
I_PGOOD = 2mA
V_PGOOD = 5V
V_FB with Respect to Set Regulated Voltage
V_FB Ramping Negative
Hysteresis
V_FB with Respect to Set Regulated Voltage
V_FB Ramping Positive
Hysteresis
MIN TYP MAX UNITS
0.2 0.4
V
±1
μA
–13 –10 –7
%
2.5
%
7
10
13
%
2.5
%
25
μs
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may
cause permanent damage to the device. Exposure to any Absolute Maximum
Ratings for extended periods may affect device reliability and lifetime.
Note 2: The LTC3890-2 is tested under pulsed load conditions such that
T_J ≈ T_A. The LTC3890E-2 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 LTC3890I-2 is guaranteed
over the –40°C to 125°C operating junction temperature range, the
LTC3890H-2 is guaranteed over the –40°C to 150°C operating junction
temperature range and the LTC3890MP-2 is tested and guaranteed over
the –55°C to 150°C operating junction temperature range.
High junction temperatures degrade operating lifetimes; operating lifetime
is derated for junction temperatures greater than 125°C. Note that 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: 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 4: The LTC3890-2 is tested in a feedback loop that servos V_ITH1,2 to a
specified voltage and measures the resultant V_FB. The specification at 85°C is not
tested in production and is assured by design, characterization and correlation
to production testing at other temperatures (125°C for the LTC3890E-2/
LTC3890I-2, 150°C for the LTC3890H-2/LTC3890MP-2). For the LTC3890MP-2,
the specification at –40°C is not tested in production and is assured by design,
characterization and correlation to production testing at –55°C.
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).
38902f
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