RX8130CE :I2C-Bus Interface Build in backup battery charge control function
- Built in frequency adjusted 32.768 kHz crystal unit
- Interface Type
- Interface voltage range
1.6V to 5.5V
- Wide voltage for time keeping
1.1V to 5.5V
- Low backup current
300 nA ( Typ. ) / 3 V
- Auto power switching function:Switchover by main power supply monitor.
- Backup battery charge control function: For the rechargeable lithium batteries.
- Reset functions with a delay:Detect a main power supply and remove the reset.
- The various function include full calendar, alarm, timer, etc.
- Epson prepared Linux driver for development http://www5.epsondevice.com/en/information/support/linux_rtc/
- * The I2C-BUS is a trademark of NXP Semiconductors.
The registered trademark Linux® is used pursuant to a sublicense from LMI(Linux Mark Institute)
- I2C-Bus interface.
- Auto power switching function
- The VDD voltage is monitored and it switches to the backup power supply by the automatic operation. The switch voltage to the backup power supply. 1.25V (Min.)
- Even if the main power supply voltage is decreased, the current flow from the backup power supply is prevented.
- Charge control function for the rechargeable lithium batteries.
- Stop charging automatically by detecting the full charge.
- Records in the register detecting the backup power supply voltage decrease.
- Reset function with a delay
- When the main power is supplied, reset output is released.The release voltage is selected by the register. (2.80V / 2.75V)
- Delay time from the voltage rise detection is 60ms Typ.
- Frequency output function
- Output frequency is selectable from 32.768kHz, 1024Hz,1Hz.
- Timer function
- Selectable in 1/4096 second from 65535 hours.
- Timer source clock are 1hour, 1min, 64Hz, 4096Hz.
- It is automatically recorded to TF-bit at the time of event occurrence, and possible to output with /IRQ pin.
|Signal Name||I / O||Function|
|SCL||input||Serial clock input pin.|
|SDA||Input / Output||Data input and output pin.|
|FOUT||Output||Frequency output pin with output control function. (C-MOS)Output frequency can be selected
as 32.768kHz, 1024Hz, 1Hz.
|/ RST||Output||Reset output pin.(N-ch open drain)
In case of VDD voltage drop detection, a reset signal is outputted.
In case of VDD voltage rise detection, it is released reset signal after 60ms.
|/ IRQ||Output||Interrupts output by Alarm and Timer events.(N-ch open drain)|
|VDD||-||This is a power-supply pin. It can impress the voltage unlike VIO.|
|VIO||-||This is a interface power supply pin. This is a pin to supply the voltage same as a host.|
|Vout||-||Internal voltage output pin. Connect smoothing capacitor of 1.0µF|
|VBAT||-||This is a power supply pin for backup battery.
This is a pin to connect a large-capacity capacitor, a secondary battery,a primary battery.
In a backup power supply operating range, the voltage is supplied inside by this pin.
|GND||-||Connected to a ground|
Terminal connection/External dimensions
Refer to application manual for details.
Recommended Operating Conditions
|Operating supply voltage||VDD||-||1.25||3.0||5.5||V|
|Clock supply voltage||VCLK||-||1.1||3.0||5.5||V|
|VDD detect voltage||-VDET2||VDD,Fall||1.20||1.30||1.40||V|
|Frequency tolerance||Δ f / f||Ta = +25 °C
VDD = 3.0 V
|B : 5 ± 23*||x 10-6|
|Oscillation start-up time||tSTA||VDD =2.75V to 5.5V||1 Max.||s|
*Equivalent to 1 minute of monthly deviation (excluding offset.)
Current consumption characteristics
|Current consumption||IBK||SCL=SDA = "L" , VBAT=3.0V ,VDD=VIO=0.0V||-||300||500||nA|
|V32K||SCL=SDA = "H" , FOUT=32.768kHz, /IRQ=OFF, VDD=VIO=3.0V, FOUT pin CL=15pF CHGEN=L or VBAT≥VDET3||-||3.5||4.0||µA|