參數(shù)資料
型號(hào): RV5C386A-E2
廠(chǎng)商: RICOH COMPANY LTD
元件分類(lèi): XO, clock
英文描述: I2C-bus Real-Time Clock ICs with Voltage Monitoring Function
中文描述: 0 TIMER(S), REAL TIME CLOCK, PDSO10
封裝: 4 X 2.90 MM, 1.20 MM HEIGHT, SSOP-10
文件頁(yè)數(shù): 7/42頁(yè)
文件大?。?/td> 362K
代理商: RV5C386A-E2
PRELIMINARY RV5C386A
12345
- 7 -
12. GENERAL DESCRIPTION
(1) Interface with CPU
The RV5C386A is connected to the CPU by two signal lines SCL and SDA, through which it reads and writes
data from and to the CPU. Since the output of the I/O pin of SDA is open drain, data interfacing with a CPU
different supply voltage is possible by applying pull-up resistors on the circuit board. The maximum clock
frequency of 400kHz (at VDD
2.5V) of SCL enables data transfer in I
2
C-Bus fast mode.
(2) Clock and Calendar Function
The RV5C386A reads and writes time data from and to the CPU in units ranging from seconds to the last two
digits of the calendar year. The calendar year will automatically be identified as a leap year when its last two
digits are a multiple of 4. Also available is the 1900 / 2000 identification bit for Year 2000 compliance.
Consequently, leap years up to the year 2099 can automatically be identified as such.
*) The year 2000 is a leap year while the year 2100 is not a leap year.
(3) Alarm Function
The RV5C386A incorporates the alarm interrupt circuit configured to generate interrupt signals to the CPU at
preset times. The alarm interrupt circuit allows two types of alarm settings specified by the Alarm_W
registers and the Alarm_D registers. The Alarm_W registers allow week, hour, and minute alarm settings
including combinations of multiple day-of-week settings such as "Monday, Wednesday, and Friday" and
"Saturday and Sunday". The Alarm_D registers allow hour and minute alarm settings. The Alarm_W
outputs from /INTRB pin, and the Alarm_D outputs from /INTRA pin. The current /INTRA or /INTRB
conditions specified by the flag bits for each alarm function can be checked from the CPU by using a polling
function.
(4) High-precision Oscillation Adjustment Function
The RV5C386A has built-in oscillation stabilization capacitors (CG and CD), which can be connected to an
external crystal oscillator to configure an oscillation circuit. To correct deviations in the oscillation frequency
of the crystal oscillator, the oscillation adjustment circuit is configured to allow correction of a time count gain
or loss (up to
±
1.5 ppm at 25
°
C) from the CPU within a maximum range of approximately + 189 ppm in
increments of approximately 3 ppm. Such oscillation frequency adjustment in each system has the following
advantages:
* Allows timekeeping with much higher precision than conventional RTCs while using a crystal oscillator with
a wide range of precision variations.
* Corrects seasonal frequency deviations through seasonal oscillation adjustment.
* Allows timekeeping with higher precision particularly with a temperature sensing function out of RTC,
through oscillation adjustment in tune with temperature fluctuations.
(5) Oscillation Halt Sensing Function and Supply Voltage Monitoring Function
The RV5C386A incorporates an oscillation halt sensing circuit equipped with internal registers configured to
record any past oscillation halt, thereby identifying whether they are powered on from 0 volts or battery
backed-up. As such, the oscillation halt sensing circuit is useful for judging the validity of time data.
The RV5C386A also incorporates a supply voltage monitoring circuit equipped with internal registers
configured to record any drop in supply voltage below a certain threshold value. Supply voltage monitoring
threshold settings can be selected between 2.1 and 1.6 volts through internal register settings. The
oscillation halt sensing circuit is configured to confirm the established invalidation of time data in contrast to
the supply voltage monitoring circuit intended to confirm the potential invalidation of time data. Further, the
supply voltage monitoring circuit can be applied to battery supply voltage monitoring.
相關(guān)PDF資料
PDF描述
RV5C387A I2C-bus Real-Time Clock ICs with Voltage Monitoring Function
RV5C387A-E2 I2C-bus Real-Time Clock ICs with Voltage Monitoring Function
RV5VE001A CRYSTAL 20.0 MHZ 20PF
RV5VE001C-E1 MULTI-POWER SUPPLY
RV5VE001C-E2 MULTI-POWER SUPPLY
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
RV5C387A 制造商:RICOH 制造商全稱(chēng):RICOH electronics devices division 功能描述:I2C-bus Real-Time Clock ICs with Voltage Monitoring Function
RV5C387A_03 制造商:RICOH 制造商全稱(chēng):RICOH electronics devices division 功能描述:I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC WITH VOLTAGE MONITORING FUNCTION
RV5C387AE2 制造商:未知廠(chǎng)家 制造商全稱(chēng):未知廠(chǎng)家 功能描述:Industrial Control IC
RV5C387A-E2 制造商:RICOH 制造商全稱(chēng):RICOH electronics devices division 功能描述:I2C-bus Real-Time Clock ICs with Voltage Monitoring Function
RV5LAYSB102A 制造商: 功能描述: 制造商:undefined 功能描述: