Datasheet

LTC3864
4
3864f
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
R
UP
Gate Pull-Up Resistance Gate High 2 Ω
R
DN
Gate Pull-Down Resistance Gate Low 0.9 Ω
PGOOD and Overvoltage
V
PGL
PGOOD Voltage Low I
PGOOD
= 2mA 0.2 0.4 V
I
PG
PGOOD Leakage Current V
PGOOD
= 5V 1 µA
%PGD PGOOD Trip Level V
FB
Ramping Negative with Respect to V
REG
Hysteresis
–13 –10
2.5
–7 %
%
V
FB
Ramping Positive with Respect to V
REG
Hysteresis
7 10
2.5
13 %
%
t
PGDLY
PGOOD Delay PGOOD Going High to Low
PGOOD Going Low to High
100
100
µs
µs
V
FBOV
V
FB
Overvoltage Lockout Threshold GATE Going High without Delay,
V
FB(OV)
-V
FB(NOM)
in Percent
10 %
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, unless otherwise noted. (Note 4)
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: Continuous operation above the specified maximum operating
junction temperature may impair device reliability or permanently damage
the device.
Note 3: The junction temperature (T
J
in °C) is calculated from the ambient
temperature (T
A
in °C) and power dissipation (P
D
in Watts) as follows:
T
J
= T
A
+ (P
D
• θ
JA
)
where θ
JA
(in °C/W) is the package thermal impedance provided in the Pin
Configuration section for the corresponding package.
Note 4: The LTC3864 is tested under pulsed loading conditions such that
T
J
≈ T
A
. The LTC3864E is guaranteed to meet performance specifications
from 0°C to 85°C operating junction temperature range. The LTC3864E
specifications over the –40°C to 125°C operating junction temperature
range are assured by design, characterization and correlation with statistical
process controls. The LTC3864I is guaranteed to meet performance
specifications over the –40°C to 125°C operating junction temperature
range, the LTC3864H is guaranteed over the –40°C to 150°C operating
junction temperature range, and the LTC3864MP is guaranteed and tested
over the full –55°C to 150°C operating junction temperature range. High
junction temperatures degrade operating lifetimes; operating lifetime is
derated for junction temperatures greater than 125°C. 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.
Note 5: The LTC3864 is tested in a feedback loop that adjust V
FB
to achieve
a specified error amplifier output voltage (on ITH pin).