Datasheet

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
± 3.4 x 10
-6
/ -40 ºC to +85 ºC
± 8.0 x 10
-6
/ +85 ºC to +105 ºC
• XB
± 5.0 x 10
-6
/ -40 ºC to +85 ºC
± 8.0 x 10
-6
/ +85 ºC to +105 ºC
• 32.768 kHz frequency output function
• FOUT pin output (C-MOS output), CL=30 pF
• Output selectable: 32.768 kHz, 1024 Hz, 1 Hz
•Event detection function
 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 function
 Timer source clock are 1min., 1sec., 64Hz, 4096Hz.
 24-bit-presettable counter (244us to about 32years.)
•Alarm function
Alarm function can be set to day of week, day, hour, and minute.
•Internal state output function
 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.
REAL TIME CLOCK MODULE (I
2
C-Bus)
Built-in 32.768 kHz-DTCXO
RX 8804CE
•Built in frequency adjusted 32.768 kHz crystal unit and DTCXO.
•Interface Type : I
2
C-Bus interface (400kHz)
•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
2
C-BUS is a trademark of NXP Semiconductors.
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
VDD
-
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
3.2 ± 0.2
1.0Max.
Electrical Characteristics
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Operating voltage
VDD
Interface voltage
1.6
3.0
5.5
V
Temp. compensated Voltage
VTEM
Temp. compensated voltage
1.5
3.0
5.5
V
Clock supply voltage
VCLK
Internal clock
1.5
3.0
5.5
V
Operating temperature
TOPR
No condensation
-40
+25
+105
ºC
Stability
f/f
XA
Ta= -40 ºC  +85 ºC
±3.4
1
10
-6
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)
IDD1
fSCL=0Hz, /INT=VDD,
FOE =GND,FOUT: OFF
Temp. Compensation
interval 2.0 s.
VDD = 5V
-
0.4
1.6
A
Current consumption (2)
IDD2
VDD = 3V
-
0.35
1.5

1)
Equivalent to ±9 seconds of month deviation.
2)
Equivalent to ±21 seconds of month deviation. 
3)
Equivalent to ±13 seconds of month deviation.
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)
Frequency
tolerance
( ×10
-6
)
Tuning fork X'tal
32.768 kHz DTCXO
95
105