- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄67723 > ISL12022MIBZR5421 (INTERSIL CORP) REAL TIME CLOCK, PDSO20 PDF資料下載
參數(shù)資料
| 型號： | ISL12022MIBZR5421 |
| 廠商： | INTERSIL CORP |
| 元件分類： | 時鐘/數(shù)據(jù)恢復及定時提取 |
| 英文描述： | REAL TIME CLOCK, PDSO20 |
| 封裝： | ROHS COMPLIANT, PLASTIC, MS-013AC, SOIC-20 |
| 文件頁數(shù)： | 19/29頁 |
| 文件大?。?/td> | 395K |
| 代理商： | ISL12022MIBZR5421 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁當前第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁
ISL12022MR5421
26
FN7576.1
June 4, 2010
“read” section. For a random read of the Control/Status
Registers, the slave byte must be “1101111x” in both
places.
Write Operation
A Write operation requires a START condition, followed by
a valid Identification Byte, a valid Address Byte, a Data
Byte, and a STOP condition. After each of the three
bytes, the ISL12022MR5421 responds with an ACK. At
this time, the I2C interface enters a standby state.
Read Operation
A Read operation consists of a three byte instruction,
followed by one or more Data Bytes (see Figure 20).
The master initiates the operation issuing the following
sequence: a START, the Identification byte with the R/W
bit set to “0”, an Address Byte, a second START, and a
second Identification byte with the R/W bit set to “1”.
After each of the three bytes, the ISL12022MR5421
responds with an ACK. Then the ISL12022MR5421
transmits Data Bytes as long as the master responds
with an ACK during the SCL cycle following the eighth
bit of each byte. The master terminates the read
operation (issuing a STOP condition) following the last
bit of the last Data Byte (see Figure 20).
The Data Bytes are from the memory location indicated
by an internal pointer. This pointer’s initial value is
determined by the Address Byte in the Read operation
instruction, and increments by one during transmission
of each Data Byte. After reaching the memory location
2Fh, the pointer “rolls over” to 00h, and the device
continues to output data for each ACK received.
Application Section
Battery Backup Details
The ISL12022MR5421 has automatic switchover to
battery backup when the VDD drops below the VBAT
mode threshold. A wide variety of backup sources can be
used, including standard and rechargeable lithium,
supercapacitors, or regulated secondary sources. The
serial interface is disabled in battery backup, while the
oscillator and RTC registers are operational. The SRAM
register contents are powered to preserve their contents
as well.
The input voltage range for VBAT is 1.8V to 5.5V, but
keep in mind the temperature compensation only
operates for VBAT > 2.7V. Note that the device is not
guaranteed to operate with a VBAT < 1.8V, so the battery
should be changed before discharging to that level. It is
strongly advised to monitor the low battery indicators in
the status registers and take action to replace discharged
batteries.
If a supercapacitor is used, it is possible that it may
discharge to below 1.8V during prolonged power-down.
Once powered up, the device may lose serial bus
communications until both VDD and VBAT are powered
down together. To avoid that situation, including
situations where a battery may discharge deeply, the
circuit in Figure 19 can be used.
The diode, DBAT will add a small drop to the battery
voltage but will protect the circuit should battery voltage
drop below 1.8V. The jumper is added as a safeguard
should the battery ever need to be disconnected from the
circuit.
The VDD negative slew rate should be limited to below
the data sheet spec (10V/ms) otherwise battery
switchover can be delayed, resulting in SRAM contents
corruption and oscillator operation interruption.
Some applications will require separate supplies for the
RTC VDD and the I2C pull-ups. This is not advised, as it
may compromise the operation of the I2C bus. For
applications that do require serial bus communication
with the RTC VDD powered down, the SDA pin must be
pulled low during the time the RTC VDD ramps down to
0V. Otherwise, the device may lose serial bus
communications once VDD is powered up, and will return
to normal operation ONLY once VDD and VBAT are both
powered down together.
Layout Considerations
The ISL12022MR5421 contains a quarts crystal and
requires special handling during PC board assembly.
Excessive shock and vibrations should be avoided,
especially with automated handling equipment.
Ultrasound cleaning is not advisable as it subjects the
crystal to resonance and possible failure. See also Note 5
on page 5 in the specifications tables, which pertains to
solder reflow effects on oscillator accuracy.
The part of the package that has NC pins from pin 1 to 5
and from pin 16 to 20 contains the crystal. Low
frequency RTC crystals are known to pick up noise very
easily if layout precautions are not followed, even
embedded within a plastic package. Most instances of
erratic clocking or large accuracy errors can be traced to
the susceptibility of the oscillator circuit to interference
from adjacent high speed clock or data lines. Careful
FIGURE 18. SLAVE ADDRESS, WORD ADDRESS AND
DATA BYTES
SLAVE
ADDRESS BYTE
D7
D6
D5
D2
D4
D3
D1
D0
A0
A7
A2
A4
A3
A1
DATA BYTE
A6
A5
1
10
1
R/
1
WORD
ADDRESS
FIGURE 19. SUGGESTED BATTERY BACKUP CIRCUIT
DBAT
CBAT
CIN
BAT43W
0.1F
VDD = 2.7V
VBAT = 1.8V
JBAT
ISL12022MR5421
VDD
GND
VBAT
TO 3.2V
TO 5.5V
+
ISL12022MR5421
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ISL12028AIB27Z-T | REAL TIME CLOCK, PDSO14 |
| ISL8705IBZT | DSP-ADDRESS SEQUENCER, PDSO14 |
| ISL8703IBZT | DSP-ADDRESS SEQUENCER, PDSO14 |
| ISP1160BD-S | UNIVERSAL SERIAL BUS CONTROLLER, PQFP64 |
| ISP1160BD/01,118 | UNIVERSAL SERIAL BUS CONTROLLER, PQFP64 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ISL12022MIBZ-T | 功能描述:實時時鐘 REAL TIME CLK & TEMP COMPENSATED CRYSTAL RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時間格式:HH:MM:SS RTC 存儲容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
| ISL12022MIBZ-T7A | 功能描述:IC RTC/CALENDAR TEMP SNSR 20SOIC RoHS:否 類別:集成電路 (IC) >> 時鐘/計時 - 實時時鐘 系列:- 產(chǎn)品培訓模塊:Obsolescence Mitigation Program 標準包裝:1 系列:- 類型:時鐘/日歷 特點:警報器，閏年，SRAM 存儲容量:- 時間格式:HH:MM:SS（12/24 小時） 數(shù)據(jù)格式:YY-MM-DD-dd 接口:SPI 電源電壓:2 V ~ 5.5 V 電壓 - 電源，電池:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-WDFN 裸露焊盤 供應商設(shè)備封裝:8-TDFN EP 包裝:管件 |
| ISL12022MIBZ-TR5421 | 功能描述:實時時鐘 REAL TIME CLK W/MFK IMPROVED ESD AIR RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時間格式:HH:MM:SS RTC 存儲容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
| ISL12022MR5421 | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:Low Power RTC with Battery Backed SRAM, Integrated 5ppm |
| ISL12022M-R5421 | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:High-Accuracy RTC Modules, Feature-Rich RTCs |
發(fā)布緊急采購，3分鐘左右您將得到回復。