Actual size

Real time clock module

Block diagram

Overview

INTERRUPTS

CONTROLLER

ALARM REGISTER

/ INT

BUS

INTERFACE

CIRCUIT

( 32.768 kHz )

CONTROL

REGISTER

DIVIDER

CLOCK

POWER

CONTROLLER

and

SDA

VDD

SCL

CALENDR

TIMER REGISTER

DTCXO

CONTROLLER

FOUT

FOUT

FOE

CONTROLLER

SOUT

SOUT

CONTROLLER

EVENT DETECTION

EVIN

CAPTURE

BUFFER

VDD

SYSTEM

CONTROLLER

•

Stability

• XA

• XB

• FOUT pin output (C-MOS output), CL=30 pF

• Output selectable: 32.768 kHz, 1024 Hz, 1 Hz

 When trigger input to EVIN-pin or specified by program, time and date

is recorded. The EVIN-pin with pull-up resistor that is releasable.

 Timer source clock are 1min., 1sec., 64Hz, 4096Hz.

 24-bit-presettable counter (244us to about 32years.)



Alarm function can be set to day of week, day, hour, and minute.

 SOUT pin output (C-MOS output),

 It outputs selected flag-bit value or specified value(H or L).

Pin Function

Terminal connection

/External dimensions

(Unit:mm)

T

Specifications (characteristics)

 Refer to application manual for details.

Built-in 32.768 kHz-DTCXO

•Built in frequency adjusted 32.768 kHz crystal unit and DTCXO.

•Interface Type

•Interface voltage range

: 1.6 V to 5.5 V

•Temp. compensated voltage range

: 1.5 V to 5.5 V

•Timekeeping voltage range

: 1.5 V to 5.5 V

•Selectable clock output (32.768 kHz, 1024 Hz, 1 Hz)

•The various functions full calendar, alarm, timer, event detection.

•The time-stamp synchronizing to the event detection of EVIN-pin.

• The SOUT-pin outputs that selected flag bit value.

• Applications : handy equipment. an outdoor unit. an industrial machine.

*The I

Signal Name

I / O

Function

SOUT

Output

Internal state output pin.

SCL

Input

Serial clock input pin.

FOUT

Output

The pin outputs the reference clock signal.

( CMOS output )

EVIN

Input

Event input pin

-

Connected to a positive power supply

FOE

Input

The input pin for the FOUT output control.

/ INT

Output

Interrupt output (N-ch. open drain).

GND

-

Connected to a ground

T2

-

Use only for testing in the factory.

( Do not connect externally.)

SDA

I/O

Data input and output pin.

Product Number (Please contact us)

RX8804CE : X1B000371xxxx00

RX8804CE

(3.2 × 2.5 × 1.0 mm)

RX8804CE

RX8804CE

1.

FOE

10.

/INT

2.

VDD

9.

GND

3.

EVIN

8. T2

4.

FOUT

7.

SDA

5.

SCL

6.

SOUT

2.5 ± 0.2



Electrical Characteristics

Item

Symbol

Conditions

Min.

Typ.

Max.

Unit

Operating voltage

Interface voltage

1.6

3.0

5.5

V

Temp. compensated Voltage

Temp. compensated voltage

1.5

3.0

5.5

V

Clock supply voltage

Internal clock

1.5

3.0

5.5

V

Operating temperature

No condensation

-40

+25

+105

ºC

Stability

f/f

XA

Ta

= -40 ºC  +85 ºC

±3.4

1

Ta

= +85 ºC  +105 ºC

±8.0

2

XB

Ta

=-40 ºC  +85 ºC

±5.0

3

Ta

= +85 ºC  +105 ºC

±8.0

2

Current consumption (1)

FOE =GND,FOUT:

OFF

Temp. Compensation

interval 2.0 s.

-

0.4

1.6

A

Current consumption (2)

-

0.35

1.5



32.768 kHz-DTCXO Frequency temperature characteristics (Example)

Frequency temperature characteristics

-30

-25

-20

-15

-10

-5

0

5

10

-45

-35

-25

-15

-5

5

15

25

35

45

55

65

75

85

Temperature (ºC)

Tuning fork X'tal

32.768 kHz DTCXO

95

105