TLE4278G Datasheet, PDF (13/19 Pages) Siemens Semiconductor Group – 5-V Low-Drop Fixed Voltage Regulator

TLE 4278 G
Watchdog Activating
The calculation of the external resistor which adjusts the watchdog switch off threshold
can be done by Equation (4):
R_WADJ = V_WADJ,th × (I_Q/I_WADJ)/I_Q,act
(4)
Definitions:
• V_WADJ,th = switch off threshold, typical 1.35 V
• I_Q/I_WADJ = current ratio, typical 720
• I_Q,act = switch off load current
TLE 4278 G
Ι
Q
Band-Gap-
Reference
WADJ
R _WADJ
Figure 7
HIGH
Watchdog
active
LOW
Watchdog
disabled
GND
AES03072
Data Sheet
13
Rev. 1.3, 2005-04-29