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 bymonitoring 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.
- · Links to convenient tools
Click here
- · Links to Driver and Video contents
Click here
RX8111CE
Design Support Data Download
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 | ||
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
(Unit: mm)
Footprint (Recommended)
(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)
Links
Video contents: How to use Real Time Clock Module evaluation board(RX8900CE, RX8804CE)
Video contents: RX8111CE: Battery backup switchover function
Video contents: RX8111CE: Time stamp function
Video contents: RX8111CE: Wake up timer function
Video contents: RX4111CE: Battery backup switchover function
Real Time Clock: RX8900CE / RX8804CE Evaluation Tools
Linux® Driver for Real Time Clock Module
The registered trademark Linux® is used pursuant to a sublicense from LMI (Linux Mark Institute)
