M61529FP

Rev.1.00, Sep.04.2003, page 21 of 23

System Reset

(a) IC’s condition of power supply turn on

This IC is the system composition which compulsory resetting when power supply turn on.

• Time constant of power supply is used, and reset pulse is formed.

• When V

• The operation time of reset is released reset pulse [2] from transmitted reset pulse [1].

• Trst = [Timing A + about 20us] is time of released reset pulse.

(Timing A is time of V

t

V

VCC

VDD(Internal power supply)

VSS(Internal power supply)

<Timing of reset>

Transmitted reset pulse

Released reset pulse

Operation time of reset

5.5V

About 20

µs

A

1

2

Released reset pulse

Trst

(Normal operation)

t

V

<REF Voltage>

VCC

Voltage of 1pin

=REF Voltage

about200ms(C=100

µF)

1.5V

Operation of Analog circuit

1/2 VCC

B

Trst

The power supply is turned on, and resetting is released after Trst, and the reception of the serial

data becomes possible in Logic block.

However, REF voltage doesn't operate in less than 1.5V in the analog block. Make REF voltage is to

transmit serial data by more than 1.5V.

• REF Voltage

≥ Time of REF=1.5V =Timing B

(Timing B is time when analog block operates and to become possible.)

<EX> Capacitor of 1pin =100

µF

Becomes REF

≥ 1.5V in about 200ms.

(b) IC’s condition of power supply turn off

Internal power supply (V

All the data set up when Logic turned it off become invalid.