Datasheet

LM22678
SNVS585K –SEPTEMBER 2008–REVISED MARCH 2013 www.ti.com
Electrical Characteristics (continued)
Limits in standard type are for T
J
= 25°C only; limits in boldface type apply over the junction temperature (T
J
) range of -40°C
to +125°C. Minimum and Maximum limits are ensured through test, design, or statistical correlation. Typical values represent
the most likely parametric norm at T
A
= T
J
= 25°C, and are provided for reference purposes only. Unless otherwise specified:
V
IN
= 12V.
Min Typ Max
Parameter Test Conditions Units
(1) (2) (1)
I
BIAS
Feedback Bias Current V
FB
= 1.3V (ADJ Version Only) 230 nA
V
EN
Enable Threshold Voltage Falling 1.3 1.6 1.9 V
V
ENHYST
Enable Threshold Hysteresis 0.6 V
I
EN
Enable Input Current EN Input = 0V 6 µA
T
SD
Thermal Shutdown Threshold 150 °C
θ
JA
Thermal Resistance Junction to ambient thermal 22 °C/W
resistance
(3)
(3) The value of θ
JA
for the PFM package of 22°C/W is valid if package is mounted to 1 square inch of copper. The θ
JA
value can range
from 20 to 30°C/W depending on the amount of PCB copper dedicated to heat transfer. See application note AN-1797 SNVA328 for
more information.
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