The DS17285, DS17485, DS17885, DS17287, DS17487, and DS17887 real-time clocks (RTCs) are designed to be successors to the industry-standard DS12885 and DS12887. The DS17285, DS17485, and DS17885 (hereafter referred to as the DS17x85) provide a real-time clock/calendar, one time-of-day alarm, three maskable interrupts with a common interrupt output, a programmable square wave, and 114 bytes of battery-backed NV SRAM. The DS17x85 also incorporates a number of enhanced functions including a silicon serial number, power-on/off control circuitry, and 2K, 4K, or 8Kbytes of battery-backed NV SRAM. The DS17287, DS17487, and DS17887 (hereafter referred to as the DS17x87) integrate a quartz crystal and lithium energy source into a 24-pin encapsulated DIP package. The DS17x85 and DS17x87 power-control circuitry allows the system to be poweredon by an external stimulus such as a keyboard or by a time-and-date (wake-up) alarm. The active-low PWR output pin is triggered by one or either of these events, and is used to turn on an external power supply. The active-low PWR pin is under software control, so that when a task is complete, the system power can then be shut down.For all devices, the date at the end of the month is automatically adjusted for months with fewer than 31 days, including correction for leap years. It also operates in either 24-hour or 12-hour format with an AM/PM indicator. A precision temperature-compensated circuit monitors the status of VCC. If a primary power failure is detected, the device automatically switches to a backup supply. A lithium coin cell battery can be connected to the VBAT input pin on the DS17x85 to maintain time and date operation when primary power is absent. The DS17x85 and DS17x87 include a VBAUX input used to power auxiliary functions such as active-low PWR control. The device is accessed through a multiplexed byte-wide interface.ApplicationsEmbedded SystemsNetwork Hubs, Bridges, and RoutersSecurity SystemsUtility Meters

The DS1746 is a full-function, year-2000-compliant (Y2KC), real-time clock/calendar (RTC) and 128k x 8 nonvolatile static RAM. User access to all registers within the DS1746 is accomplished with a byte-wide interface as shown in Figure 1. The RTC information and control bits reside in the eight uppermost RAM locations. The RTC registers contain century, year, month, date, day, hours, minutes, and seconds data in 24-hour binary-coded decimal (BCD) format. Corrections for the date of each month and leap year are made automatically. The RTC clock registers are double buffered to avoid access of incorrect data that can occur during clock update cycles. The double-buffered system also prevents time loss as the timekeeping countdown continues unabated by access to time register data. The DS1746 also contains its own power-fail circuitry, which deselects the device when the VCC supply is in an out of tolerance condition. This feature prevents loss of data from unpredictable system operation brought on by low VCC as errant access and update cycles are avoided.

The DS17285, DS17485, DS17885, DS17287, DS17487, and DS17887 real-time clocks (RTCs) are designed to be successors to the industry-standard DS12885 and DS12887. The DS17285, DS17485, and DS17885 (hereafter referred to as the DS17x85) provide a real-time clock/calendar, one time-of-day alarm, three maskable interrupts with a common interrupt output, a programmable square wave, and 114 bytes of battery-backed NV SRAM. The DS17x85 also incorporates a number of enhanced functions including a silicon serial number, power-on/off control circuitry, and 2K, 4K, or 8Kbytes of battery-backed NV SRAM. The DS17287, DS17487, and DS17887 (hereafter referred to as the DS17x87) integrate a quartz crystal and lithium energy source into a 24-pin encapsulated DIP package. The DS17x85 and DS17x87 power-control circuitry allows the system to be poweredon by an external stimulus such as a keyboard or by a time-and-date (wake-up) alarm. The active-low PWR output pin is triggered by one or either of these events, and is used to turn on an external power supply. The active-low PWR pin is under software control, so that when a task is complete, the system power can then be shut down.For all devices, the date at the end of the month is automatically adjusted for months with fewer than 31 days, including correction for leap years. It also operates in either 24-hour or 12-hour format with an AM/PM indicator. A precision temperature-compensated circuit monitors the status of VCC. If a primary power failure is detected, the device automatically switches to a backup supply. A lithium coin cell battery can be connected to the VBAT input pin on the DS17x85 to maintain time and date operation when primary power is absent. The DS17x85 and DS17x87 include a VBAUX input used to power auxiliary functions such as active-low PWR control. The device is accessed through a multiplexed byte-wide interface.ApplicationsEmbedded SystemsNetwork Hubs, Bridges, and RoutersSecurity SystemsUtility Meters

The MAX9321B low-skew differential receiver/driver is designed for clock and data distribution. The differential input can be adapted to accept a single-ended input by connecting the on-chip VBB supply to an input as a reference voltage.The MAX9321B features ultra-low propagation delay (172ps) and part-to-part skew (20ps) with 24mA maximum supply current, making this device ideal for clock buffering or repeating. For interfacing to differential PECL and LVPECL signals, these devices operate over a +3.0V to +5.5V supply range, allowing high-performance clock and data distribution in systems with a nominal 3.3V or 5.0V supply. For differential ECL and LVECL operation, this device operates from a -3.0V to -5.5V supply. The MAX9321B is offered in industry-standard 8-pin SO and TSSOP packages.ApplicationsLow-Jitter Data RepeaterPrecision Clock Buffers

The DS1023 is an 8-bit programmable delay line similar in function to the DS1020/DS1021.Additional features have been added to extend the range of applications:The internal delay line architecture has been revised to allow clock signals to be delayed by up to a fullperiod or more. Combined with an on-chip reference delay (to offset the inherent or 'step zero' delay ofthe device) clock phase can now be varied over the full 0-360 degree range.On-chip gating is provided to allow the device to provide a pulse width modulated output, triggered bythe input with duration set by the programmed value.Alternatively the output signal may be inverted on chip, allowing the device to perform as a free-runningoscillator if the output is (externally) connected to the input.

The DS1023 is an 8-bit programmable delay line similar in function to the DS1020/DS1021.Additional features have been added to extend the range of applications:The internal delay line architecture has been revised to allow clock signals to be delayed by up to a fullperiod or more. Combined with an on-chip reference delay (to offset the inherent or 'step zero' delay ofthe device) clock phase can now be varied over the full 0-360 degree range.On-chip gating is provided to allow the device to provide a pulse width modulated output, triggered bythe input with duration set by the programmed value.Alternatively the output signal may be inverted on chip, allowing the device to perform as a free-runningoscillator if the output is (externally) connected to the input.

The DS1302 trickle-charge timekeeping chip contains a real-time clock/calendar and 31 bytes of static RAM. It communicates with a microprocessor via a simple serial interface. The real-time clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with an AM/PM indicator.Interfacing the DS1302 with a microprocessor is simplified by using synchronous serial communication. Only three wires are required to communicate with the clock/RAM: CE, I/O (data line), and SCLK (serial clock). Data can betransferred to and from the clock/RAM 1 byte at a time or in a burst of up to 31 bytes. The DS1302 is designed to operate on very low power and retain data and clock information on less than 1µW.The DS1302 is the successor to the DS1202. In addition to the basic timekeeping functions of the DS1202, the DS1302 has the additional features of dual power pins for primary and backup power supplies, programmable trickle charger for VCC1, and seven additional bytes of scratchpad memory.

The DS1307 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. Address and data are transferred serially through an I²C, bidirectional bus. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. The DS1307 has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply. Timekeeping operation continues while the part operates from the backup supply.

Real Time Clock (RTC) IC Phantom Time Chip Parallel 20-TSSOP (0.173", 4.40mm Width)

DS1315 Features:

• Real-Time Clock Keeps Track of Hundredths of Seconds, Seconds, Minutes, Hours, Days, Date of the Month, Months, and Years
• Automatic Leap Year Correction Valid Up to 2100
• No Address Space Required to Communicate with RTC
• Provides Nonvolatile Controller Functions for Battery Backup of SRAM
• Supports Redundant Battery Attachment for High-Reliability Applications
• Full ±10% V_CC Operating Range
• +3.3V or +5V Operation
• Industrial (–40°C to +85°C) Operating Temperature Ranges Available

DS1315 Description:

The DS1315 Phantom Time Chip is a combination of a CMOS timekeeper and a nonvolatile memory controller. In the absence of power, an external battery maintains the timekeeping operation and provides power for a CMOS static RAM. The watch keeps track of hundredths of seconds, seconds, minutes, hours, day, date, month, and year information. The last day of the month is automatically adjusted for months with less than 31 days, including leap year correction. The watch operates in one of two formats: a 12-hour mode with an AM/PM indicator or a 24-hour mode. The nonvolatile controller supplies all the necessary support circuitry to convert a CMOS RAM to a nonvolatile memory. The DS1315 can be interfaced with either RAM or ROM without leaving gaps in memory.

 

 

The DS1315 Phantom Time Chip is a combination of a CMOS timekeeper and a nonvolatile memory controller. In the absence of power, an external battery maintains the timekeeping operation and provides power for a CMOS static RAM. The watch keeps track of hundredths of seconds, seconds, minutes, hours, day, date, month, and year information. The last day of the month is automatically adjusted for months with less than 31 days, including leap year correction. The watch operates in one of two formats: a 12-hour mode with an AM/PM indicator or a 24-hour mode. The nonvolatile controller supplies all the necessary support circuitry to convert a CMOS RAM to a nonvolatile memory. The DS1315 can be interfaced with either RAM or ROM without leaving gaps in memory.