LTC3831-1 Datasheet, PDF (3/20 Pages) Linear Technology – High Power Synchronous Switching Regulator Controller for DDR Memory Termination

LTC3831-1
ELECTRICAL CHARACTERISTICS The q denotes specifications that apply over the full operating temperature
range, otherwise specifications are at T_A = 25°C. V_CC, PV_CC1, PV_CC2 = 5V, V_R+ = 1.5V, V_R– = GND, unless otherwise noted. (Note 2)
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
V_IH
SHDN Input High Voltage
V_IL
SHDN Input Low Voltage
I_IN
SHDN Input Current
I_SS
Soft-Start Source Current
I_SSIL
Maximum Soft-Start Sink Current
Undercurrent Limit
R⁺
R⁺ Input Resistance
q 2.4
V
q
0.8
V
V_SHDN = V_CC
q
0.1
1
µA
V_SS = 0V, V_IMAX = 0V, V_IFB = V_CC
q –8
–12 –16
µA
V_IMAX = V_CC, V_IFB = 0V, V_SS = V_CC (Note 8),
PV_CC1 = 7V (Note 7)
1.6
mA
53.3
kΩ
t_r, t_f
t_NOV
DC_MAX
Driver Rise/Fall Time
Driver Nonoverlap Time
Maximum TG Duty Cycle
Figure 1, PV_CC1 = PV_CC2 = 5V (Note 5)
q
80
250
ns
Figure 1, PV_CC1 = PV_CC2 = 5V (Note 5)
q 25
120 250
ns
Figure 1, V_FB = 0V (Note 7), PV_CC1 = 7V
q 91
95
%
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
Note 3: Supply current in normal operation is dominated by the current
needed to charge and discharge the external FET gates. This will vary with
the LTC3831-1 operating frequency, operating voltage and the external
FETs used.
Note 4: The LTC3831EGN-1 is guaranteed to meet performance
specifications from 0°C to 70°C. Specifications over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls.
Note 5: Rise and fall times are measured using 10% and 90% levels. Duty
cycle and nonoverlap times are measured using 50% levels.
Note 6: Guaranteed by design, not subject to test.
Note 7: PV_CC1 must be higher than V_CC by at least 2V for TG to operate at
95% maximum duty cycle and for the current limit protection circuit to be
active.
Note 8: The current limiting amplifier can sink but cannot source current.
Under normal (not current limited) operation, the output current will be
zero.
Note 9: 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 opera-
tion above the specified maximum operating junction temperature may impair
device reliability.
Note 10: The minimum and maximum limits for I_MAX over temperature
includes the intentional temperature coefficient of 3300ppm/°C. This induced
temperature coefficient counteracts the typical temperature coefficient of the
external power MOSFET on-resistance. This results in a relatively flat current
limit over temperature for the application.
38311f
3