Datasheet

LTC3421
3
3421f
PARAMETER CONDITIONS MIN TYP MAX UNITS
Frequency Accuracy ● 0.85 1 1.15 MHz
SYNC Input High ● 2.2 V
SYNC Input Low ● 0.8 V
SYNC Input Current ● 0.01 1 µA
ENB Input High ● 1.2 V
ENB Input Low ● 0.4 V
ENB Input Current ● 1 µA
SHDN Input High V
OUT
= 0V (Initial Start-Up) 1.00 V
V
OUT
> 2.4V 0.65 V
SHDN Input Low 0.25 V
SHDN Input Current ● 0.01 1 µA
REF Output Voltage ● 1.183 1.22 1.257 V
REF Output Current Range –100 8 µA
Error Amp Transconductance 45 µs
LBI Threshold Falling Edge ● 0.58 0.6 0.62 V
LBI Input Current ● 0.01 1 µA
LBO Low Voltage V
IN
= 0V, I
SINK
= 1mA 12.0 50 mV
V
IN
= 0V, I
SINK
= 20mA 0.25 0.5 V
LBO Leakage V
PGOOD
= 5.5V 0.01 1 µA
SS Current Source V
SS
= 1V 1.2 2.4 5 µA
BURST Threshold Voltage Falling Edge 0.87 0.97 1.07 V
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 1.2V, V
OUT
= 3.3V, R
T
= 28k, unless otherwise noted.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC3421E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the 40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Current is measured into the V
OUTS
pin since the supply current is
bootstrapped to the output. The current will reflect to the input supply by
(V
OUT
/V
IN
) • Efficiency. The outputs are not switching.
Note 4: Once V
OUT
is greater than 2.4V, the IC is not dependent on the V
IN
supply.
Note 5: 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 specified maximum operating junction
temperature may impair device reliability.