LTC3615/LTC3615-1
4
3615fa
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
SW1–SW2
Output Phase Shift Between SW1
and SW2 (LTC3615)
VPHASE < 0.15 SVIN
0Deg
0.35 SVIN < VPHASE < 0.65 SVIN
90
Deg
VPHASE > 0.85 SVIN
180
Deg
Output Phase Shift Between SW1
and SW2 (LTC3615-1)
VPHASE < 0.65 SVIN
140
Deg
VPHASE > 0.85 SVIN
180
Deg
VSRLIM
Voltage at SRLIM to Enable DDR
Mode
(Note 9)
SVIN – 0.3
V
VMODE
(Note 9)
Internal Burst Mode Operation
0.3
V
Pulse-Skipping Mode
SVIN – 0.3
V
Forced Continuous Mode
1.1
SVIN 0.58
V
External Burst Mode Operation
0.5
0.85
V
PGOOD
Power Good Voltage Windows
TRACK/SSx = SVIN, Entering Window
VFBx Ramping Up
VFBx Ramping Down
–3.5
3.5
–6
6
%
TRACK/SSx = SVIN, Leaving Window
VFBx Ramping Up
VFBx Ramping Down
9
–9
11
–11
%
tPGOOD
Power Good Blanking Time
Entering/Leaving Window
70
105
140
μs
RPGOOD
Power Good Pull-Down On-Resistance I = 10mA
8
12
30
Ω
VRUN
Enable Pin
Input High
Input Low
l
1
0.4
V
Pull-Down Resistance
4
MΩ
ELECTRICAL CHARACTERISTICS
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 LTC3615/LTC3615-1 are tested under pulsed load conditions
such that TJ ≈ TA. The LTC3615E/LTC3615E-1 are guaranteed to meet
performance specications over the 0°C to 85°C operating junction
temperature range. Specications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3615I/LTC3615I-1 are
guaranteed to meet specications over the full –40°C to 125°C operating
junction temperature range. Note that the maximum ambient temperature
is determined by specic operating conditions in conjunction with board
layout, the rated package thermal resistance and other environmental
factors. Note that the maximum ambient temperature consistent with
these specications is determined by specic operating conditions in
conjunction with board layout, the rated package thermal impedance
and other environmental factors. The junction temperature (TJ, in °C) is
calculated from the ambient temperature
(TA, in °C) and power dissipation (PD, in watts) according to the formula:
TJ = TA + (PD θJA)
where θJA (in °C/W) is the package thermal impedence.
Note 3: This parameter is tested in a feedback loop which servos VFB1,2 to
the midpoint for the error amplier (VITH1,2 = 0.75V).
Note 4: External compensation on ITH pin.
Note 5: Tying the ITH pin to SVIN enables internal compensation and AVP
mode for the selected channel.
Note 6: Dynamic supply current is higher due to the internal gate charge
being delivered at the switching frequency.
Note 7: See description of the TRACK/SS pin in the Pin Functions section.
Note 8: When sourcing current, the average output current is dened
as owing out of the SW pin. When sinking current, the average output
current is dened as owing into the SW pin. Sinking mode requires the
use of forced continuous mode.
Note 9: See description of the MODE pin in the Pin Functions section.
Note 10: Guaranteed by design and correlation to wafer level
measurements for QFN packages.
Note 11: 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 specied maximum operating junction
temperature may impair device reliability or permanently damage the
device.
The
l denotes the specications which apply over the full operating
junction temperature range, otherwise specications are at TA = 25°C (Note 2), SVIN = PVINx = 3.3V, RT = 178k, RSRLIM = 40.2k, unless
otherwise specied (Note 2).