DataSheet8.cn


PDF ( 数据手册 , 数据表 ) ISL12026

零件编号 ISL12026
描述 Real Time Clock/Calendar
制造商 Intersil Corporation
LOGO Intersil Corporation LOGO 


1 Page

No Preview Available !

ISL12026 数据手册, 描述, 功能
®
Data Sheet
ISL12026, ISL12026A
November 30, 2010
FN8231.9
Real Time Clock/Calendar with I2C Bus™
and EEPROM
The ISL12026 and the ISL12026A devices are micro power
real time clocks with timing and crystal compensation,
clock/calender, power-fail indicator, two periodic or polled
alarms, intelligent battery backup switching, and integrated
512x8-bit EEPROM configured in 16 Bytes per page.
The oscillator uses an external, low-cost 32.768kHz crystal.
The real time clock tracks time with separate registers for
hours, minutes, and seconds. The device has calendar
registers for date, month, year and day of the week. The
calendar is accurate through 2099, with automatic leap year
correction.
The ISL12026 and ISL12026A have different types of Power
Control Settings. The ISL12026 uses the Legacy Mode
Setting, which follows conditions set in X1226 products. The
ISL12026A uses the Standard Mode Setting. Please refer to
“Power Control Operation” on page 13 for more details. Also,
please refer to “I2C Communications During Battery Backup”
on page 22 for important details.
Pinouts
ISL12026, ISL12026A
(8 LD SOIC)
TOP VIEW
X1
X2
IRQ/FOUT
GND
1
2
3
4
8 VDD
7 VBAT
6 SCL
5 SDA
ISL12026, ISL12026A
(8 LD TSSOP)
TOP VIEW
VBAT
VDD
X1
X2
1
2
3
4
8 SCL
7 SDA
6 GND
5 IRQ/FOUT
Features
• Real Time Clock/Calendar
- Tracks Time in Hours, Minutes and Seconds
- Day of the Week, Day, Month and Year
- 3 Selectable Frequency Outputs
• Two Non-Volatile Alarms
- Settable on the Second, Minute, Hour, Day of the Week,
Day or Month
- Repeat Mode (Periodic Interrupts)
• Automatic Backup to Battery or SuperCap
• On-Chip Oscillator Compensation
- Internal Feedback Resistor and Compensation
Capacitors
- 64 Position Digitally Controlled Trim Capacitor
- 6 Digital Frequency Adjustment Settings to ±30ppm
• 512x8 Bits of EEPROM
- 16-Byte Page Write Mode (32 total pages)
- 8 Modes of BlockLock™ Protection
- Single Byte Write Capability
• High Reliability
- Data Retention: 50 years
- Endurance: >2,000,000 Cycles Per Byte
• I2C Interface
- 400kHz Data Transfer Rate
• 800nA Battery Supply Current
• Package Options
- 8 Ld SOIC and 8 Ld TSSOP Packages
• Pb-Free (RoHS Compliant)
Applications
• Utility Meters
• HVAC Equipment
• Audio/Video Components
• Set-Top Box/Television
• Modems
• Network Routers, Hubs, Switches, Bridges
• Cellular Infrastructure Equipment
• Fixed Broadband Wireless Equipment
• Pagers/PDA
• POS Equipment
• Test Meters/Fixtures
• Office Automation (Copiers, Fax)
• Home Appliances
• Computer Products
• Other Industrial/Medical/Automotive
1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas Inc. 2005, 2006, 2007, 2008, 2010. All Rights Reserved.
Intersil (and design) and BlockLock are trademarks owned by Intersil Corporation or one of its subsidiaries.
I2C Bus™ is a trademark owned by NXP Semiconductors Netherlands, B.V. All other trademarks mentioned are the property of their respective owners.







ISL12026 pdf, 数据表
ISL12026, ISL12026A
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 ISL12026 to supply a timebase for the real
time clock. Internal compensation circuitry provides high
accuracy over the operating temperature range from
-40°C to +85°C. This oscillator compensation network can
be used to calibrate the crystal timing accuracy
over-temperature either during manufacturing or with an
external temperature sensor and microcontroller for active
compensation. X2 is intended to drive a crystal only, and
should not drive any external circuit.
X1
X2
FIGURE 7. RECOMMENDED CRYSTAL CONNECTION
Real Time Clock Operation
The Real Time Clock (RTC) uses an external 32.768kHz
quartz crystal to maintain an accurate internal representation
of the second, minute, hour, day, date, month and year. The
RTC has leap-year correction. 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 ISL12026 powers up
after the loss of both VDD and VBAT, 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 on the ACK bit prior to RTC data output) into
a separate latch to avoid time changes during the read
operation. The clock continues to run. Alarms occurring during
a read are unaffected by the read operation.
Writing to the Real Time Clock
The time and date may be set by writing to the RTC
registers. RTC Register should be written ONLY with Page
Write. To avoid changing the current time by an incomplete
write operation, write to the all 8 bytes in one write operation.
When writing the RTC registers, the new time value is
loaded into a separate buffer at the falling edge of the clock
during the Acknowledge. This new RTC value is loaded into
the RTC Register by a stop bit at the end of a valid write
sequence. An invalid write operation aborts the time update
procedure and the contents of the buffer are discarded. After
a valid write operation, the RTC will reflect the newly loaded
data beginning with the next “one second” clock cycle after
the stop bit is written. The RTC continues to update the time
while an RTC register write is in progress and the RTC
continues to run during any non-volatile write sequences.
Accuracy of the Real Time Clock
The accuracy of the Real Time Clock depends on the
accuracy of the quartz crystal that is used as the time base
for the RTC. Since the resonant frequency of a crystal is
temperature dependent, the RTC performance will also be
dependent upon temperature. The frequency deviation of
the crystal is a function of the turnover temperature of the
crystal from the crystal’s nominal frequency. For example, a
>20ppm frequency deviation translates into an accuracy of
>1 minute per month. These parameters are available from
the crystal manufacturer. Intersil’s RTC family provides
on-chip crystal compensation networks to adjust
load-capacitance to tune oscillator frequency from -34ppm to
+80ppm when using a 12.5pF load crystal. For more detailed
information, see “Application Section” on page 19.
Clock/Control Registers (CCR)
The Control/Clock Registers are located in an area separate
from the EEPROM array and are only accessible following a
slave byte of “1101111x” and reads or writes to addresses
[0000h:003Fh]. The clock/control memory map has memory
addresses from 0000h to 003Fh. The defined addresses are
described in the Table 1. Writing to and reading from the
undefined addresses are not recommended.
CCR Access
The contents of the CCR can be modified by performing a
byte or a page write operation directly to any address in the
CCR. Prior to writing to the CCR (except the status register),
however, the WEL and RWEL bits must be set using a three
step process (see “Writing to the Clock/Control Registers” on
page 12).
The CCR is divided into 5 sections. These are:
1. Alarm 0 (8 bytes; non-volatile)
2. Alarm 1 (8 bytes; non-volatile)
3. Control (5 bytes; non-volatile)
4. Real Time Clock (8 bytes; volatile)
5. Status (1 byte; volatile)
Each register is read and written through buffers. The
non-volatile portion (or the counter portion of the RTC) is
updated only if RWEL is set and only after a valid write
operation and stop bit. A sequential read or page write
operation provides access to the contents of only one section
of the CCR per operation. Access to another section requires
a new operation. A read or write can begin at any address in
the CCR.
It is not necessary to set the RWEL bit prior to writing the
status register. See “Status Register (SR)” on page 9.
supports a single byte read or write only. Continued reads or
writes from this section terminates the operation.
8 FN8231.9
November 30, 2010







ISL12026 equivalent, schematic
ARRAY
CCR
ISL12026, ISL12026A
DEVICE IDENTIFIER
1010
1 1 0 1 1 1 1 R/W
0 0 0 0 0 0 0 A8
A7 A6 A5 A4 A3 A2 A1 A0
SLAVE ADDRESS BYTE
BYTE 0
WORD ADDRESS 1
BYTE 1
WORD ADDRESS 0
BYTE 2
D7 D6 D5 D4 D3 D2 D1 D0
DATA BYTE
BYTE 3
FIGURE 15. SLAVE ADDRESS, WORD ADDRESS, AND DATA BYTES (16 BYTE PAGES)
SIGNALS FROM
THE MASTER
SDA BUS
SIGNALS FROM
THE SLAVE
S
T
A
R SLAVE
T ADDRESS
WORD
ADDRESS 1
WORD
ADDRESS 0
DATA
S
T
O
P
1 1 110 0000000
A A AA
C C CC
K K KK
FIGURE 16. BYTE WRITE SEQUENCE
Following the Slave Byte is a two byte word address. The
word address is either supplied by the master device or
obtained from an internal counter. On power up the internal
address counter is set to address 0h, so a current address
read of the EEPROM array starts at address 0. When
required, as part of a random read, the master must supply
the 2 Word Address Bytes as shown in Figure 15.
In a random read operation, the slave byte in the “dummy
write” portion must match the slave byte in the “read”
section. That is if the random read is from the array the slave
byte must be 1010111x in both instances. Similarly, for a
random read of the Clock/Control Registers, the slave byte
must be 1101111x in both places.
Write Operations
Byte Write
For a write operation, the device requires the Slave Address
Byte and the Word Address Bytes. This gives the master
access to any one of the words in the array or CCR. (Note:
Prior to writing to the CCR, the master must write a 02h, then
06h to the status register in two preceding operations to
enable the write operation. See “Writing to the Clock/Control
Registers” on page 12). Upon receipt of each address byte,
the ISL12026 responds with an acknowledge. After receiving
both address bytes the ISL12026 awaits the 8 bits of data.
After receiving the 8 data bits, the ISL12026 again responds
with an acknowledge. The master then terminates the
transfer by generating a stop condition. The ISL12026 then
begins an internal write cycle of the data to the non-volatile
memory. During the internal write cycle, the device inputs
are disabled, so the device will not respond to any requests
from the master. The SDA output is at high impedance (see
Figure 16).
A write to a protected block of memory is ignored, but will still
receive an acknowledge. At the end of the write command,
the ISL12026 will not initiate an internal write cycle, and will
continue to ACK commands.
Byte writes to all of the non-volatile registers are allowed,
except the DWAn registers which require multiple byte writes
or page writes to trigger non-volatile writes. See “Device
Operation” on page 12 for more information.
Page Write
The ISL12026 has a page write operation. It is initiated in the
same manner as the byte write operation; but instead of
terminating the write cycle after the first data byte is
transferred, the master can transmit up to 15 more bytes to
the memory array and up to 7 more bytes to the clock/control
registers. The RTC registers require a page write (8 bytes),
16 FN8231.9
November 30, 2010










页数 24 页
下载[ ISL12026.PDF 数据手册 ]


分享链接

Link :

推荐数据表

零件编号描述制造商
ISL12020Low Power RTCIntersil Corporation
Intersil Corporation
ISL12020MLow Power RTCIntersil Corporation
Intersil Corporation
ISL12021Real Time ClockIntersil Corporation
Intersil Corporation
ISL12022Low Power RTCIntersil
Intersil

零件编号描述制造商
STK15C88256-Kbit (32 K x 8) PowerStore nvSRAMCypress Semiconductor
Cypress Semiconductor
NJM4556DUAL HIGH CURRENT OPERATIONAL AMPLIFIERNew Japan Radio
New Japan Radio
EL1118-G5 PIN LONG CREEPAGE SOP PHOTOTRANSISTOR PHOTOCOUPLEREverlight
Everlight


DataSheet8.cn    |   2020   |  联系我们   |   搜索  |  Simemap