データシートサーチシステム |
|
X1205S8 データシート(PDF) 7 Page - Intersil Corporation |
|
X1205S8 データシート(HTML) 7 Page - Intersil Corporation |
7 / 22 page 7 FN8097.2 September 23, 2005 DESCRIPTION (continued) The powerful Dual Alarms can be set to any Clock/Calendar value for a match. For instance, every minute, every Tuesday, or 5:23 AM on March 21. The alarms can be polled in the Status Register or provide a hardware interrupt (IRQ Pin). There is a repeat mode for the alarms allowing a periodic interrupt. The device offers a backup power input pin. This VBACK pin allows the device to be backed up by battery or SuperCap. The entire X1205 device is fully operational from 2.7 to 5.5 volts and the clock/calendar portion of the X1205 device remains fully operational down to 1.8 volts (Standby Mode). PIN DESCRIPTIONS Serial Clock (SCL) The SCL input is used to clock all data into and out of the device. The input buffer on this pin is always active (not gated). Serial Data (SDA) SDA is a bidirectional pin used to transfer data into and out of the device. It has an open drain output and may be wire ORed with other open drain or open collector outputs. The input buffer is always active (not gated). An open drain output requires the use of a pull-up resistor. The output circuitry controls the fall time of the output signal with the use of a slope controlled pull-down. The circuit is designed for 400kHz 2-wire interface speeds. VBACK This input provides a backup supply voltage to the device. VBACK supplies power to the device in the event the VCC supply fails. This pin can be connected to a battery, a Supercap or tied to ground if not used. Interrupt Output – IRQ This is an interrupt signal output. This signal notifies a host processor that an alarm has occurred and requests action. It is an open drain active low output. X1, X2 The X1 and X2 pins are the input and output, respectively, of an inverting amplifier. An external 32.768kHz quartz crystal is used with the X1205 to supply a timebase for the real time clock. The recommended crystal is a Citizen CFS206-32.768KDZF. Internal compensation circuitry is included to form a complete oscillator circuit. Care should be taken in the placement of the crystal and the layout of the circuit. Plenty of ground plane around the device and short traces to X1 and X2 are highly recommended. See Application section for more recommendations. Figure 2. Recommended Crystal connection POWER CONTROL OPERATION The power control circuit accepts a VCC and a VBACK input. The power control circuit powers the clock from VBACK when VCC < VBACK - 0.2V. It will switch back to power the device from VCC when VCC exceeds VBACK. Figure 3. Power Control REAL TIME CLOCK OPERATION The Real Time Clock (RTC) uses an external 32.768kHz quartz crystal to maintain an accurate internal representation of second, minute, hour, day, date, month, and year. The RTC has leap-year correc- tion. The clock also corrects for months having fewer than 31 days and has a bit that controls 24 hour or AM/PM format. When the X1205 powers up after the loss of both VCC and VBACK, the clock will not operate until at least one byte is written to the clock register. Reading the Real Time Clock The RTC is read by initiating a Read command and specifying the address corresponding to the register of the Real Time Clock. The RTC Registers can then be read in a Sequential Read Mode. Since the clock runs continuously and a read takes a finite amount of time, there is the possibility that the clock could change during the course of a read operation. In this device, the time is latched by the read command (falling edge of the clock NC = No internal connection X1 X2 VBACK VCC IRQ SCL SDA VSS 1 2 3 4 7 8 6 5 8-Pin TSSOP X1205 X1 X2 VBACK VCC IRQ SCL SDA VSS 1 2 3 4 7 8 6 5 8-Pin SOIC X1 X2 VBACK In Voltage VCC On Off X1205 |
同様の部品番号 - X1205S8 |
|
同様の説明 - X1205S8 |
|
|
リンク URL |
プライバシーポリシー |
ALLDATASHEET.JP |
ALLDATASHEETはお客様のビジネスに役立ちますか? [ DONATE ] |
Alldatasheetは | 広告 | お問い合わせ | プライバシーポリシー | リンク交換 | メーカーリスト All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |