LTC3831_15 Datasheet, PDF (3/20 Pages) Linear Technology – High Power Synchronous Switching Regulator Controller for DDR Memory Termination

LTC3831
ELECTRICAL CHARACTERISTICS The ● 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+ = 2.5V, V_R– = GND, unless otherwise noted. (Note 2)
SYMBOL
V_COMPMAX
Δf_OSC/ΔI_FREQSET
A_V
g_m
I_COMP
I_MAX
V_IH
V_IL
I_IN
I_SS
I_SSIL
R⁺
PARAMETER
Maximum V_COMP
Frequency Adjustment
Error Amplifier Open-Loop DC Gain
Error Amplifier Transconductance
Error Amplifier Output Sink/Source
Current
I_MAX Sink Current
I_MAX Sink Current Tempco
SHDN Input High Voltage
SHDN Input Low Voltage
SHDN Input Current
Soft-Start Current
Maximum Soft-Start Sink Current
Undercurrent Limit
R⁺ Input Resistance
CONDITIONS
V_FB = 0V, PV_CC1 = 8V
MIN
● 46
● 520
V_IMAX = V_CC
9
●
4
V_IMAX = V_CC (Note 6)
● 2.4
●
V_SHDN = V_CC
●
V_SS = 0V, V_IMAX = 0V, V_IFB = V_CC
● –8
V_IMAX = V_CC, V_IFB = 0V, V_SS = V_CC (Note 8),
PV_CC1 = 8V
TYP
2.85
10
55
650
100
12
12
3300
0.1
–12
1.6
49.5
MAX UNITS
V
kHz/μA
dB
780
μmho
μA
15
μA
20
μA
ppm/°C
V
0.8
V
1
μA
–16
μA
mA
kΩ
t_r, t_f
t_NOV
DC_MAX
Driver Rise/Fall Time
Driver Nonoverlap Time
Maximum TG Duty Cycle
Figure 2, PV_CC1 = PV_CC2 = 5V (Note 5)
●
80
250
ns
Figure 2, PV_CC1 = PV_CC2 = 5V (Note 5)
● 25
120
250
ns
Figure 2, V_FB = 0V (Note 5), PV_CC1 = 8V ● 91
95
%
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: 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 operating frequency, operating voltage and the external FETs
used.
Note 4: The LTC3831EGN is guaranteed to meet performance
specifications from 0°C to 85°C. Specifications over the –40°C to 85°C
operating temperature range are assured by design, characterization
and correlation with statistical process controls. The LTC 3831IGN is
guaranteed to meet performance specifications over the full –40°C to 85°C
temperature range.
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 2.5V 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
operation above the specified maximum operating junction temperature may
impair device reliability.
3831fb
3