Table of Contents
Advertisement
8XC196NT USER'S MANUAL
5
4
EXTINT
3
V PP , Volts
2
1
2
Figure 13-4. Typical Voltage on the V
Select a resistor that will not interfere with the discharge current. In most cases, values between
200 kΩ and 1 MΩ should perform satisfactorily. When selecting the capacitor, determine the
worst-case discharge time needed for the oscillator to stabilize, then use this formula to calculate
an appropriate value for C
×
T
I
DIS
------------------- -
C
=
1
V
t
where:
C
is the capacitor value, in farads
1
T
is the worst-case discharge time, in seconds
DIS
I
is the discharge current, in amperes
V
is the threshold voltage
t
If powerdown is re-entered and exited before C
less time for the voltage to ramp down to the threshold. Therefore, the device
will take less time to exit powerdown.
13-8
200 µA C 1 Discharge
4
6
8
10
.
1
NOTE
R 1 x C 1 Recovery
Time Constant
Pullup On
Code Execution Resumes
12
14
16
18
Time, ms
Pin While Exiting Powerdown
PP
charges to V
1
CC
20
22
A0151-01
, it will take
Advertisement
Table of Contents
