LTC3864 Datasheet, PDF (4/28 Pages) Linear Technology – 60V Low IQ Step-Down DC/DC Controller with 100% Duty Cycle Capability

LTC3864
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)
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
R_UP
Gate Pull-Up Resistance
R_DN
Gate Pull-Down Resistance
PGOOD and Overvoltage
Gate High
Gate Low
2
Ω
0.9
Ω
V_PGL
I_PG
%PGD
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
I_PGOOD = 2mA
0.2
0.4
V
V_PGOOD = 5V
1
µA
V_FB Ramping Negative with Respect to V_REG
–13
–10
–7
%
Hysteresis
2.5
%
t_PGDLY
V_FBOV
PGOOD Delay
V_FB Overvoltage Lockout Threshold
V_FB Ramping Positive with Respect to V_REG
Hysteresis
PGOOD Going High to Low
PGOOD Going Low to High
GATE Going High without Delay,
V_FB(OV)-V_FB(NOM) in Percent
7
10
13
%
2.5
%
100
µs
100
µs
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: 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).
3864f
4