LTC3614_15 Datasheet, PDF (4/30 Pages) Linear Technology – 4A, 4MHz Monolithic Synchronous Step-Down DC/DC Converter

LTC3614
Electrical Characteristics The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C (Note 2). V_IN = 3.3V, RT/SYNC = SV_IN unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
V_MODE
Internal Burst Mode Operation
(Note 9)
Pulse-Skipping Mode
 
SV_IN – 0.3 
0.3
V
V
Forced Continuous Mode
External Burst Mode Operation
1.1
SV_IN • 0.58
V
0.45
 
0.8
V
PGOOD
Power Good Voltage Windows
TRACK/SS = SV_IN, Entering Window
V_FB Ramping Up
V_FB Ramping Down
TRACK/SS = SV_IN, Leaving Window
V_FB Ramping Up
V_FB Ramping Down
–3
–6
%
3
6
%
9
11
%
–9
–11
%
t_PGOOD
Power Good Blanking Time
Entering and Leaving Window
70
105
140
µs
R_PGOOD
V_RUN
Power Good Pull-Down On-Resistance
RUN voltage
Input High
Input Low
8
17
33
Ω
l
1
l
V
0.4
V
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 LTC3614 is tested under pulsed load conditions such that T_J ≈
T_A. The LTC3614E is guaranteed to meet specifications from 0°C to 85°C
junction temperature. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3614I is guaranteed
to meet specifications over the –40°C to 125°C operating junction
temperature, the LTC3614H is guaranteed to meet specifications over the
–40°C to 150°C operating junction temperature range and the LTC3614MP
is guaranteed and tested to meet specifications over the full –55°C to
150°C operating junction temperature range. High junction temperatures
degrade operating lifetimes; operating lifetime is derated for temperature
greater than 125°C. Note that the maximum ambient temperature
consistent with these specifications is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
impedance and other environmental factors.
The junction temperature (T_J) is calculated from the ambient temperature
(T_A) and power dissipation (P_D) according to the formula: T_J = T_A + (P_D
• θ_JA°C/W), where θ_JA is the package thermal impedance. The maximum
ambient temperature is determined by specific operating conditions in
conjunction with board layout, the rated package thermal resistance and
other environmental factors.
Note 3: This parameter is tested in a feedback loop which servos V_FB to
the midpoint for the error amplifier (V_ITH = 0.75V).
Note 4: External compensation on ITH pin.
Note 5: Tying the ITH pin to SV_IN enables the internal compensation and
AVP mode.
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: In sourcing mode the average output current is flowing out of the
SW pin. In sinking mode the average output current is flowing into the SW
Pin.
Note 9: See description of the MODE pin in the Pin Functions section.
Note 10: Guaranteed by correlation and design 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 150°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
3614fc
4
For more information www.linear.com/LTC3614