X1227 Xicor, X1227 Datasheet
X1227
Available stocks
Related parts for X1227
X1227 Summary of contents
Page 1
... Home Appliances • Computer Products • Other Industrial / Medical / Automotive DESCRIPTION The X1227 device is a Real Time Clock with clock/ calendar, two polled alarms with integrated 512x8 EEPROM, oscillator compensation, CPU Supervisor (POR/LVS and WDT) and battery backup switch. The oscillator uses an external, low-cost 32.768kHz crystal ...
Page 2
... X1227 device remains fully operational down to 1.8 volts (Standby Mode). The X1227 device provides 4K bits of EEPROM with 8 modes of BlockLock™ control. The BlockLock allows a safe, secure memory for critical user and configuration data, while allowing a large user storage area. ...
Page 3
... 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 X1227 powers up after the loss of both V and V CC ...
Page 4
... X1227 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 sec- tion requires a new operation ...
Page 5
... Years divisible by 100 are not leap years, unless they are also divisible by 400. This means that the year 2000 is a leap year, the year 2100 is not. The X1227 does not correct for the leap year in the year 2100. REV 1.1.20 1/13/03 ...
Page 6
... RTCF: Real Time Clock Fail Bit—Volatile This bit is set to a ‘1’ after a total power failure. This is a read only bit that is set by hardware (X1227 inter- nally) when the device powers up after having lost all power to the device. The bit is set regardless of ...
Page 7
... X1227 Analog Trimming Register (ATR) (Non-volatile) Six analog trimming Bits from ATR5 to ATR0 are pro- vided to adjust the on-chip loading capacitance range. The on-chip load capacitance ranges from 3.25pF to 18.75pF. Each bit has a different weight for capaci- tance adjustment. Using a Citizen CFS-206 crystal ...
Page 8
... X1227 POWER ON RESET Application of power to the X1227 activates a Power On Reset Circuit that pulls the RESET pin active. This signal provides several benefits. – It prevents the system microprocessor from starting to operate with insufficient voltage. – It prevents the processor from operating prior to sta- bilization of the oscillator. – ...
Page 9
... However, in applica- tions where the standard V is not exactly right TRIP higher precision is needed in the V X1227 threshold may be adjusted. The procedure is described below, and uses the application of a nonvol- atile write control signal. Figure 5. Set V Level Sequence (V ...
Page 10
... X1227 Figure 6. Reset V Level Sequence TRIP RESET SCL SDA AEh Note: BP0, BP1, BP2 must be disabled. SERIAL COMMUNICATION Interface Conventions The device supports a bidirectional bus oriented proto- col. The protocol defines any device that sends data onto the bus as a transmitter, and the receiving device as the receiver ...
Page 11
... When this R/W bit is a one, then a read operation is selected. A zero selects a write operation. Refer to Figure 10. After loading the entire Slave Address Byte from the SDA bus, the X1227 compares the device identifier REV 1.1.20 1/13/03 Data Stable Data Change ...
Page 12
... X1227 responds with an acknowledge. After receiving both address bytes the X1227 awaits the eight bits of data. After receiving the 8 data bits, the X1227 again responds with an acknowledge. The master then terminates the transfer by generating a stop condition. The X1227 then begins an internal write cycle of the data to the nonvolatile memory ...
Page 13
... X1227 will not initiate an internal write cycle, and will continue to ACK commands. Page Write The X1227 has a page write operation initiated in the same manner as the byte write operation; but instead of terminating the write cycle after the first data ...
Page 14
... Slave Address Byte with the R/W bit set to one, the X1227 issues an acknowledge, then transmits eight data bits. The mas- ter terminates the read operation by not responding with an acknowledge during the ninth clock and issuing a stop condition ...
Page 15
... In a similar operation called “Set Current Address,” the device sets the address if a stop is issued instead of the second start shown in Figure 16. The X1227 then goes into standby mode after the stop and all bus activity will be ignored until a start is detected. This operation loads the new address into the address counter ...
Page 16
... X1227 ABSOLUTE MAXIMUM RATINGS Temperature Under Bias ................... -65°C to +135°C Storage Temperature......................... -65°C to +150°C Voltage pin CC BACK (respect to ground)...............................-0.5V to 7.0V Voltage on SCL, SDA, X1 and X2 pin (respect to ground) ............... -0.5V to 7.0V or 0.5V above (whichever is higher) CC BACK DC Output Current .............................................. 5 mA Lead Temperature (Soldering, 10 sec) ...............300°C DC OPERATING CHARACTERISTICS (Temperature = -40° ...
Page 17
... X1227 Notes: (1) The device enters the Active state after any start, and remains active: for 9 clock cycles if the Device Select Bits in the Slave Address Byte are incorrect or until 200nS after a stop ending a read or write operation. (2) The device enters the Program state 200nS after a stop ending a write operation and continues for t (3) The device goes into the Timekeeping state 200nS after any stop, except those that initiate a nonvolatile write cycle ...
Page 18
... X1227 AC Specifications (T = -40°C to +85°C, VCC = +2.7V to +5.5V, unless otherwise specified.) A Symbol f SCL Clock Frequency SCL t Pulse width Suppression Time at inputs IN t SCL LOW to SDA Data Out Valid AA t Time the bus must be free before a new transmission can start BUF t Clock LOW Time ...
Page 19
... It is the minimum cycle time to be allowed for any nonvolatile write by the user, unless Acknowledge Polling is used. WATCHDOG TIMER/LOW VOLTAGE RESET OPERATING CHARACTERISTICS Watchdog/Low Voltage Reset Parameters (See Figures 3 and 4) Symbols Programmed Reset Trip Voltage X1227-4.5A V X1227 PTRIP X1227-2.7A X1227-2 Detect to RESET LOW RPD CC Power Up Reset Time-out Delay t PURST t ...
Page 20
... X1227 V Programming Timing Diagram TRIP TRIP RESET VPS SCL SDA AEh V Programming Parameters TRIP Parameter t V Program Enable Voltage Setup time VPS TRIP t V Program Enable Voltage Hold time VPH TRIP t V Setup time TSU ...
Page 21
... X1227 APPLICATION SECTION CRYSTAL OSCILLATOR AND TEMPERATURE COMPENSATION Xicor has now integrated the oscillator compensation circuity on-chip, to eliminate the need for external com- ponents and adjust for crystal drift over temperature and enable very high accuracy time keeping (<5ppm drift. The Xicor RTC family uses an oscillator circuit with on- chip crystal compensation network, including adjust- able load-capacitance ...
Page 22
... RTC. Care needs to be taken in layout of the RTC circuit to avoid noise pickup. Below in Fig- ure suggested layout for the X1226 or X1227 devices. Figure 15. Suggested Layout for Xicor RTC in SO-8 REV 1.1.20 1/13/03 The X1 and X2 connections to the crystal are to be kept as short as possible ...
Page 23
... X1227 by the parasitic elements in the scope probe. Applying a scope probe can possibly cause a faulty oscillator to start up, hiding other issues (although in the Xicor RTC’s, the internal circuitry assures startup when using the proper crystal and layout). The best way to analyze the RTC circuit is to power it up and read the real time clock as time advances ...
Page 24
... X1227 Referring to Figure 16, Vtrip applies to the “Internal Vcc” node which powers the entire device. This means that if Vcc is powered down and the battery voltage at Vback is higher than the Vtrip voltage, then the entire chip will be running from the battery. If Vback falls to ...
Page 25
... X1227 PACKAGING INFORMATION Pin 1 Index 0.010 (0.25) 0.020 (0.50) 0° - 8° 0.016 (0.410) 0.037 (0.937) NOTE: ALL DIMENSIONS IN INCHES (IN P ARENTHESES IN MILLIMETERS) REV 1.1.20 1/13/03 8-Lead Plastic, SOIC, Package Code S8 Pin 1 0.014 (0.35) 0.019 (0.49) 0.188 (4.78) 0.197 (5.00) (4X) 7° 0.050 (1.27) X 45° 0.0075 (0.19) 0.010 (0.25) FOOTPRINT www.xicor.com 0.150 (3.80) ...
Page 26
... X1227 PACKAGING INFORMATION 0° – 8° Detail A (20X) See Detail “A” NOTE: ALL DIMENSIONS IN INCHES (IN P ARENTHESES IN MILLIMETERS) REV 1.1.20 1/13/03 8-Lead Plastic, TSSOP, Package Code V8 .025 (.65) BSC .169 (4.3) .177 (4.5) .114 (2.9) .122 (3.1) .047 (1.20) .0075 (.19) .002 (.05) .0118 (.30) .006 (.15) .010 (.25) Gage Plane Seating Plane ...
Page 27
... Part Number 0–70°C X1227S8-4.5A X1227S8I-4.5A 0–70°C X1227V8-4.5A X1227V8I-4.5A 0–70°C X1227S8 X1227S8I 0–70°C X1227V8 X1227V8I 0–70°C X1227S8-2.7A X1227S8I-2.7A 0–70°C X1227V8-2.7A X1227V8I-2.7A 0–70°C X1227S8-2.7 X1227S8I-2.7 0–70°C X1227V8-2.7 X1227V8I-2.7 Characteristics subject to change without notice ...
Page 28
... V 1227AN = 2.7 to 5.5V +70°C, V 1227AP = 2.7 to 5.5V, -40 to +85°C, V 1227F = 2.7 to 5.5V +70°C, V 1227G = 2.7 to 5.5V, -40 to +85°C, V 8-Lead SOIC Blank = 8-Lead SOIC X1227 4.5 to 5.5V +70°C, V TRIP AM = 4.5 to 5.5V, -40 to +85°C, V Blank = 4.5 to 5.5V +70° 4.5 to 5.5V, -40 to +85°C, V TRIP AN = 2.7 to 5.5V +70° ...