Real time clock module
Block diagram
Overview
Interface type : 3 wire / 4 wire SPI-Bus
High stability
XS : ±3.0 x 10
-6
/ -40 ºC to +85 ºC (Monthly rate: ±8 seconds)
: ±5.0 x 10
-6
/ +85 ºC to +105 ºC (Monthly rate: ±13.2 seconds)
XB : ±5.0 x 10
-6
/ -40 ºC to +85 ºC (Monthly rate: ±13.2 seconds)
: ±8.0 x 10
-6
/ +85 ºC to +105 ºC (Monthly rate: ±21 seconds)
Time stamp function
Trigger source: External event (EVIN) input, voltage drop/oscillation
stop status detected, command input from the host
Record data: 1/1024 seconds to 1 second, seconds, minutes, hours,
days, months, years
Number of recordable events: Maximum 32 events
Backup power supply switching function
The VDD and VBAT voltages are monitored to switch between Normal
mode (VDD operation) and Backup mode (VBAT operation).
Clock output (FOUT)
Selectable from 32.768 kHz, 1024 Hz and 1 Hz outputs
Output can be controlled by a register or FOE input (selectable
with a register).
RX4901CE
1.
10.
2. 9.
3. 8.
4. 7.
5. 6.
2.5 ± 0.2
3.2 ± 0.2
1.0 Max.
Recommended Operating Conditions
Item Symbol
Condition Min. Typ. Max. unit
DD
Clock supply voltage
VCLK
- 1.1 3.0 5.5 V
Operating Temperature
Ta - -40 +25 +105
ºC
VDD detection voltage
-VDET1
VDD, Fall 1.35 1.45 1.55 V
Frequency Characteristics
Item Symbol
Condition Min.
Typ.
Max.
unit
Frequency
tolerance
f/f
XS
Ta = -40 to +85 C
-3 - +3
10
6
Ta = -40 to +105 C
-5 - +5
XB
Ta = -40 to +85 C
-5 - +5
Ta = -40 to +105 C
-8 - +8
start-up time
tSTA
Ta = +25 C,
VDD=1.6V5.5V
- 0.5
1.0 s
Current consumption
Ta=-40Cto+105C
Item
Symbol
Condition Min.
Typ.
Max.
unit
IDD
IBAT
VBAT = 3.0 V,
/INT= Hi-Z, FOUT: Output OFF (Hi-Z),
Temperature compensation interval: 2 s,
FSEL1= FSEL0 = 1, INIEN = 1,
- 240
1500
nA
I32k
VDD = 3.0 V,
/INT= Hi-Z, FOUT: 32 kHz output, CL = 0 pF,
Temperature compensation interval: 2 s,
FSEL1 = FSEL0 = 0, INIEN = 1,
- 1.0
3.0
A
Option
I/F Option
EVIN pin
Number
/INTpin
Number
FOUT
Number of time stamps recorded
by EVIN terminal trigge
FIFO Mode Direct Mode
SPI
3 wire
A 1 1 Yes 32 times 12 times
B 2 1 - 32 times 22 times
SPI
4 wire
C 0 1 Yes 0 time 0 time
D 1 1 - 32 times 10 times
REAL TIME CLOCK MODULE (SPI-Bus)
Built-in 32.768 kHz-DTCXO, +105C operating temperature,
Low current consumption, Built-in power supply switching circuit and
Time stamp function up to 32 records
RX4901CE
Built in frequency adjusted 32.768 kHz crystal unit and DTCXO
Interface Type : 3 wire / 4 wire SPI-Bus
Current consumption : 240 nA / 3 V (Typ.)
Auto power switching function : Automatically switches to backup power supply
by monitoring the VDD / VBAT voltage
Time stamp function : Maximum 32 time stamps
Interrupt output : Wake up every hour or every minute or every second
Alarm interruption : Day, date, hour, minute, second
Auto repeat wakeup timer interruption
Self-monitoring interruption : Crystal oscillation stop, V
BAT
low, V
DD
low
Signal Name
I / O
Function
EVIN1,2,3
Input
External event input pins. Detectable even in Backup mode.
Pull-up and pull-down is configurable by the resisters
CE Input
Slave select input pin
resistor (Typ. 300 kΩ) is included
Serial clock input pin
DI Input
Serial data input pin (4 wire)
Serial data Output pin (4 wire)
DIO
Input /
Serial data input/output pin (3 wire)
FOUT Output
Frequency output pin (CMOS). 32.768 kHz (default), 1024 Hz or 1 Hz
clock output is selectable. This pin can be switched to the wakeup timer
/INT Output
Interrupt output pin (N-ch. open drain). The wakeup timer, time update,
alarm, and/or event detection interrupt signals can be selected to output
from this pin. When two or more signals are selected, they are NORed
This pin is effective even in Backup mode.
DD
Power-supply pin
VOUT -
Internal operating voltage output pin
µF bypass capacitor to this pin
VBAT -
Backup power supply pin
Connect a backup power supply such as a large-size capacitor,
secondary battery, or primary battery.
The operating power voltage is supplied from this pin to the internal
Ground pin
RX4901CE
Product Number (2,000 pcs / Reel)
RX4901CE XS A0:X1B000471000115
RX4901CE XB A0:X1B000471000215
RX4901CE XS B0:X1B000471000315
RX4901CE XB B0:X1B000471000415
RX4901CE XS C0:X1B000471000515
RX4901CE XB C0:X1B000471000615
RX4901CE XS D0:X1B000471000715
RX4901CE XB D0:X1B000471000815
Pin
Opt. A
Opt. B
Opt. C
Opt. D
1 V
DD
2 V
OUT
3 V
BAT
4 FOUT
EVIN3
FOUT
EVIN3
5 CLK
6 CE
7 DIO DO
8 /INT
9 GND
10 EVIN2 DI