LTC3853 Datasheet, PDF (4/36 Pages) Linear Technology – Triple Output, Multiphase Synchronous Step-Down Controller

LTC3853
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C, V_IN = 15V, V_RUN1,2,3 = 5V, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
INTV_CC Linear Regulator
V_INTVCC
Internal V_CC Voltage
V_LDO INT
INTV_CC Load Regulation
V_EXTVCC
EXTV_CC Switchover Voltage
V_LDO EXT
EXTV_CC Voltage Drop
V_LDOHYS
EXTV_CC Hysteresis
Oscillator and Phase-Locked Loop
7V < V_IN < 24V
I_CC = 0mA to 50mA
EXTV_CC Ramping Positive
I_CC = 20mA, V_EXTVCC = 5V
4.8
5
5.2
V
0.5
2
%
l 4.5 4.7
V
30
75
mV
200
mV
f_NOM
f_LOW
f_HIGH
Ph_TRIPLE
Nominal Frequency
Lowest Frequency
Highest Frequency
Channel 2-Channel 1 Phase
Channel 3-Channel 2 Phase
Channel 1-Channel 3 Phase
V_FREQ = 1.2V
V_FREQ = 0V
V_FREQ ≥ 2.4V
450 500 550
kHz
210 250 290
kHz
670 750 830
kHz
120
Deg
120
Deg
120
Deg
Ph_DUAL(2+1)
Channel 2-Channel 1 Phase
Channel 3-Channel 2 Phase
Channel 1-Channel 3 Phase
V_FB2 Tied to V_IN Through 200kΩ
180
Deg
60
Deg
120
Deg
R_MODE/PLLIN
I_FREQ
PGOOD Outputs
MODE/PLLIN Input Resistance
Phase Detector Output Current
Sinking Capability
Sourcing Capability
f_MODE < f_OSC
f_MODE > f_OSC
250
kΩ
–13
μA
13
μA
V_PGL
I_PGOOD
V_PG
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
I_PGOOD = 2mA
V_PGOOD = 5V
V_FB with Respect to Set Regulated Voltage
V_FB Ramping Negative
V_FB Ramping Positive
0.1 0.3
V
±2
μA
–5 – 7.5 –10
%
5
7.5
10
%
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 LTC3853E 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 LTC3853I is guaranteed over the full
–40°C to 125°C operating temperature range.
Note 3: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formulas:
LTC3853EUJ: T_J = T_A + (P_D • 33°C/W)
Note 4: The LTC3853 is tested in a feedback loop that servos V_ITH1,2,3 to a
specified voltage and measures the resultant V_FB1,2,3.
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).
3853f
4