Microchip Technology DM160218 Data Sheet

DS40001667C-page 16

 2012-2013 Microchip Technology Inc.

Standard applications (without STEP-UP) (3.3V 

 V

DD

 3.465V): 
The system starts when (see 

• Power-up/Time-out period (t

PWRT

) is elapsed

• V

DD

 = 3.3V is already reached before the end of 

t

PWRT

 timing

The power-up sequence begins by increasing the
voltage on the V

DD

 pin (from 0V). If the slope of the V

DD

rise time is faster than 4.5 V/ms, the system starts
correctly.
If the slope is less than 4.5 V/ms, the MCLR pin must
be held low, by external circuitry, until a valid operating
V

DD

 level is reached.

MCLR

1.5V

V

DD

time

3.3V

t1: t

RSTDLY

: Reset delay typically 200 μs, 120 μs minimum

t2: t

PWRT

: Power-up Time-out

2V

t1

t2