LTC3819 Datasheet, PDF (4/32 Pages) Linear Technology – 2-Phase, High Efficiency, Step-Down Controller for Sun Server CPUs

LTC3819
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 15V, V_BIAS = 5V, V_RUN/SS = 5V unless otherwise noted.
SYMBOL PARAMETER
Oscillator and Phase-Locked Loop
f_NOM
f_LOW
f_HIGH
R_PLLIN
I_PLLFLTR
Nominal Frequency
Lowest Frequency
Highest Frequency
PLLIN Input Resistance
Phase Detector Output Current
Sinking Capability
Sourcing Capability
R_RELPHS Controller 2-Controller 1 Phase
PGOOD Output
V_PGL
I_PGOOD
V_PG
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level, Either Controller
Differential Amplifier/Op Amp Gain Block
A_DA
CMRR_DA
R_IN
Differential Amplifier Gain
Common Mode Rejection Ratio
Input Resistance
CONDITIONS
V_PLLFLTR = 1.2V
V_PLLFLTR = 0V
V_PLLFLTR ≥ 2.4V
f_PLLIN < f_OSC
f_PLLIN > f_OSC
I_PGOOD = 2mA
V_PGOOD = 5V
V_EAIN with Respect to Set Output Voltage
V_EAIN Ramping Negative
V_EAIN Ramping Positive
V_AMPMD = 0V
0V < V_CM < 5V; V_AMPMD = 0V
Measured at V_OS + Input; V_AMPMD = 0V
MIN TYP MAX UNITS
190 220 250
kHz
120 140 160
kHz
280 310 360
kHz
50
kΩ
– 15
µA
15
µA
180
Deg
0.1
0.3
V
±1
µA
–8
– 10 – 12
%
8
10
12
%
0.995
1
1.005
V/V
46
55
dB
80
kΩ
Note 1: Absolute Maximum Ratings are those values beyond which the
life of a device may be impaired.
Note 2: The LTC3819EG 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 3: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formula:
LTC3819EG: T_J = T_A + (P_D • 85°C/W)
Note 4: The LTC3819 is tested in a feedback loop that servos V_ITH to a
specified voltage and measures the resultant V_EAIN.
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 corresponds to the on inductor
peak-to-peak ripple current ≥ 40% I_MAX (see Minimum On-Time
Considerations in the Applications Information section).
Note 8: Each built-in pull-up resistor attached to the VID inputs also has a
series diode to allow input voltages higher than the VIDV_CC supply without
damage or clamping (see the Applications Information section).
3819f
4