REAL TIME CLOCK MODULE
Time stamp function and Low current consumption
RX8111CE

  • Built in frequency adjusted 32.768 kHz crystal unit
  • Interface Type
    I2C-Bus interface
  • Low backup current
    100 nA Typ. / 3 V
  • Auto power switching function
    Automatically switches to backup power supply by
    monitoring the VDD voltage
  • Time stamp function
    8 times stamped from year to 1/256 seconds.
  • Interrupt output
    Wake up every minute or every second
  • Alarm interruption in Day, date, hour, minute, second
  • Auto repeat wakeup timer interruption
  • Self-monitoring interruption: Crystal oscillation stop. VBAT low, VDD low.
  • Epson prepared Linux driver for development
    https://www5.epsondevice.com/en/information/support/linux_rtc/
    The registered trademark Linux® is used pursuant to a sublicense from LMI(Linux Mark Institute)
    * The I2C-Bus is a trademark of NXP Semiconductors

Complies with EU RoHS directive.

Complies with EU RoHS directive.

RX8111CE
RX8111CE

Block diagram

Block diagram

Overview

  • Interface Type
    • I2C-Bus interface Fast-Mode 400 kHz
  • Auto power switching function
    • The VDD voltage is monitored and it switches to the backup power supply by the automatic operation
    • Backup power supply switching voltage 1.2 V Min.
  • Clock output function
    • Output frequency is selectable from 32.768 kHz, 1024 Hz,1 Hz
  • Wakeup timer function
    • Selectable from 244 micro second to 32 years (24 bit 1 ch.)
    • Timer source clock selectable from 1/60 Hz, 1 Hz, 64 Hz, 4096 Hz
    • Auto release after interrupt output from /INT pin at timer completes
    • This operation is auto repeat with a selected cycle, it can be used like a watchdog timer
  • Time stamp function
    • 8 times stamped from year to 1/256 seconds
    • The time-stamp trigger inputs from EVIN pin, self-monitoring and I2C software command
    • EVIN pin has function of chattering-cancel
  • Alarm function
    • It is possible program from year to second
  • Self-monitoring interruption
    • Crystal oscillation stop. VBAT low, VDD low

Specifications (characteristics)

Refer to application manual for details

Item Symbol Condition Min. Typ. Max. Unit
Operating supply voltage VDD - 1.6 3.0 5.5 V
Clock supply voltage VCLK - 1.1 3.0 5.5 V
Operating temperature Ta - -40 +25 +85 °C
VDD detect voltage -VDET1 VDD, Fall 1.20 1.40 1.60 V
Frequency tolerance Δ f / f Ta = +25 °C
VDD = 3.0 V
A -11.5 - +11.5 x 10-6
B -23.0 - +23.0
Oscillation startup time tSTA VDD = 2.75 V to 5.5 V - 0.3 1.0 s
Current consumption IBAT SCL = SDA = ”L”,
FOUT = OFF, /INT=OFF,
VBAT = 3.0 V, VDD = VIO = 0.0 V
CHGEN = 0b, INIEN = 0b,
SWSEL0 = 1, SWSEL1 = 0
- 100 450 nA
I32K FOUT = 32.768 kHz, /INT = OFF,
VDD = VIO = 3.0 V
FOUT pin CL = 15 pF
- 2.0 3.0 µA
name

Pin function

Signal Name I / O Function
EVIN input External event input pin (Pull up/down and polarity are selectable by software)
SCL input Serial clock input pin
SDA Input / Output Data input and output pin
FOUT Output Frequency output (CMOS)
(frequency selection: 32.768 kHz / 1024 Hz / 1 Hz)
/INT Output Interrupts output by Alarm and Timer events (N-ch. open drain)
VDD - Power-supply pin.
It can input the voltage unlike VIO
VIO - Interface power supply pin.
Input to supply the voltage same as a host
VOUT - Internal voltage output pin. Connect smoothing capacitor of 1.0 µF surely
VBAT - This is a power supply pin for backup battery
Connect a EDLC, secondary battery, a primary battery
In the backup voltage range, supplied to IC, from this pin
GND - Ground pin

Terminal connection/External dimensions

Terminal connection External dimensions

(Unit: mm)

Footprint (Recommended)

footprint

(Unit: mm)

To maintain stable operation, provide a 0.1uF by-pass capacitor
at a location as near as possible to the power source terminal of the crystal product (between Vcc - GND)

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