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RA8900CE :I2C-Bus Interface Real Time Clock Module for Automotive
(Built-in 32.768 kHz-DTCXO, High Stability and Power Switching)
- Built in frequency adjusted 32.768 kHz crystal unit and DTCXO.
- Interface Type
I2C-Bus interface (400kHz)
- Interface voltage range
2.5V to 5.5V
- Temp. compensated voltage range
2.0V to 5.5V
- Timekeeping voltage range
1.6V to 5.5V
- Selectable clock output(32.768 kHz, 1024 Hz, 1 Hz)
- The various functions full calendar, alarm, timer, temp. sensor
- Applications : Car audio, Car navigation system, Clock
- AEC-Q200 compliant
Design Support Data Download
Block diagram
Overview
- High Stability
- UA ± 3.4 x 10-6 / -40 °C to +85 °C ( Equivalent to ±9 seconds of month deviation )
- UB ± 5.0 x 10-6 / -40 °C to +85 °C ( Equivalent to ±13 seconds of month deviation )
- UC ± 5.0 x 10-6 / -30 °C to +70 °C ( Equivalent to ±13 seconds of month deviation )
- 32.768 kHz frequency output function
- FOUT pin output (C-MOS output), CL=30 pF
- Output selectable: 32.768 kHz, 1024 Hz, 1 Hz
- Available automatic battery backup switch-over function
- Charge from VDD to backup battery connected to VBAT is possible.
VDD voltage drop(VDET3) detection and automatically switches to the backup battery.
This circuit is optimal to backup with a secondary battery and a large capacitor.
- Charge from VDD to backup battery connected to VBAT is possible.
- Timer function
- Timer function can be set up between 1/4096 second and 4095 minutes.
- Alarm function
- Alarm function can be set to day of week, day, hour, and minute.
- Temp. sensor function
- The temperature data are output to a register by a temp. sensor function. (Bank.2_Add17h)
Specifications (characteristics)
Refer to application manual for details.
Electrical Characteristics
Item | Symbol | Conditions | Min. | Typ. | Max. | Unit | ||
---|---|---|---|---|---|---|---|---|
Operating voltage | VDD | Interface voltage | 2.5 | 3.0 | 5.5 | V | ||
Temp. compensated Voltage | VTEM | Temp. compensated voltage | 2.0 | 3.0 | 5.5 | V | ||
Clock supply voltage | VCLK | Internal clock | 1.6 | 3.0 | 5.5 | V | ||
Operating temperature | TOPR | No condensation | -40 | +25 | +85 | °C | ||
Stability | Δ f/f | UA | Ta=-40°C to+85°C |
±3.4 *1 | x10-6 | |||
UB | Ta=-40°C to+85°C |
±5.0 *2 | ||||||
UC | Ta=-30°C to+70°C | |||||||
Current consumption(1) | lDD1 | fSCL=0Hz,/INT=VDD, FOE=GND, VDD=VBAT FOUT:OFF Temp. Compensation interval 2.0 s. |
VDD=5V | - | 0.72 | 1.5 | µA | |
Current consumption(2) | lDD2 | VDD=3V | - | 0.70 | 1.4 |
*1 Equivalent to ±9 seconds of month deviation.
*2 Equivalent to ±13 seconds of month deviation.
32.768 kHz-DTCXO Frequency temperature characteristics (Example)
Pin function
Signal Name | I / O | Function |
---|---|---|
T1(CE) | input | Use by the manufacture for testing. ( Do not connect externally.) |
SCL | input | Serial clock input pin. |
FOUT | output | The pin outputs the reference clock signal. ( CMOS output ) |
VBAT | - | Battery supply. This pin has charge capability to backup battery. |
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(VPP) | - | Use by the manufacture for testing. ( Do not connect externally.) |
SDA | I/O | Data input and output 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).