HT46R322/HT46R342

Rev. 1.00

21

December 21, 2006

Low Voltage Reset

- LVR

The microcontroller provides a low voltage reset circuit

in order to monitor the supply voltage of the device. If the

supply voltage of the device is within the range

battery, the LVR will automatically reset the device inter-

nally.

The LVR includes the following specifications:

form a reset function.

²OR² function with the external RES

signal to perform a chip reset.

Note:

operation at 4MHz system clock.

5 . 5 V

3 . 0 V

2 . 2 V

0 . 9 V

5 . 5 V

5 . 5 V

0 . 9 V

0 V

R e s e t S i g n a l

R e s e t

* 1

* 2

N o r m a l O p e r a t i o n

R e s e t

L V R D e t e c t V o l t a g e

Low Voltage Reset

Note:

*1: To make sure that the system oscillator has stabilised, the SST provides an extra delay of 1024 system

clock pulses before beginning normal operation.

reset mode.

OP Amplifier/Comparator

The devices include an integrated operational amplifier

or comparator, selectable via configuration option. The

default is function is comparator. The input voltage off-

set is adjustable by using a common mode input to cali-

brate the offset value.

The calibration process is as follows:

- this closes switch S3

reference voltage - closes either switch S1 or S2

OPAOP has changed.

A P N

A P P

V R

A P O

A P N

A P P

A P O

S 1

S 2

S 3