FM3104

FM3104 RAMTRON | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 25

Technical content

Features

High Integration Device Replaces Multiple Parts

• Serial Nonvolatile Memory
• Real-time Clock (RTC)
• Low Voltage Reset
• Watchdog Timer
• Early Power-Fail Warning/NMI
• Two 16-bit Event Counters
• Serial Number with Write-lock for Security Ferroelectric Nonvolatile RAM
• 4Kb, 16Kb, 64Kb, and 256Kb versions
• Unlimited Read/Write Endurance
• 10 year Data Retention
• NoDelay™ Writes Real-time Clock/Calendar
• Backup Current under 1 µA
• Seconds through Centuries in BCD format
• Tracks Leap Years through 2099
• Uses Standard 32.768 kHz Crystal (6pF)
• Software Calibration
• Supports Battery or Capacitor Backup Processor Companion
• Active-low Reset Output for VDD and Watchdog
• Programmable VDD Reset Trip Point
• Manual Reset Filtered and Debounced
• Programmable Watchdog Timer
• Dual Battery-backed Event Counter Tracks System Intrusions or other Events
• Comparator for Early Power-Fail Interrupt
• 64-bit Programmable Serial Number with Lock Fast Two-wire Serial Interface
• Up to 1 MHz Maximum Bus Frequency
• Supports Legacy Timing for 100 kHz & 400 kHz
• Device Select Pins for up to 4 Memory Devices
• RTC, Supervisor Controlled via 2-wire Interface Easy to Use Configurations
• Operates from 2.7 to 5.5V
• Small Footprint 14-pin “Green” SOIC (-G)
• Low Operating Current
• -40°C to +85°C Operation

Description

The FM31xx is a family of integrated devices that includes the most commonly needed functions for processor-based systems. Major features include nonvolatile memory available in various sizes, real- time clock, low-VDD reset, watchdog timer, nonvolatile event counter, lockable 64-bit serial number area, and general purpose comparator that can be used for an early power-fail (NMI) interrupt or other purpose. The family operates from 2.7 to 5.5V. Each FM31xx provides nonvolatile RAM available in sizes including 4Kb, 16Kb, 64Kb, and 256Kb versions. Fast write speed and unlimited endurance allow the memory to serve as extra RAM or conventional nonvolatile storage. This memory is truly nonvolatile rather than battery backed. The real-time clock (RTC) provides time and date information in BCD format. It can be permanently powered from external backup voltage source, either a battery or a capacitor. The timekeeper uses a common external 32.768 kHz crystal and provides a calibration mode that allows software adjustment of timekeeping accuracy. The processor companion includes commonly needed CPU support functions. Supervisory functions include a reset output signal controlled by either a low VDD condition or a watchdog timeout. /RST goes active when VDD drops below a programmable threshold and remains active for 100 ms after VDD rises above the trip point. A programmable watchdog timer runs from 100 ms to 3 seconds. The watchdog timer is optional, but if enabled it will assert the reset signal for 100 ms if not restarted by the host before the timeout. A flag-bit indicates the source of the reset. A general-purpose comparator compares an external input pin to the onboard 1.2V reference. This is useful for generating a power-fail interrupt (NMI) but can be used for any purpose. The family also includes a programmable 64-bit serial number that can be locked making it unalterable. Additionally it offers a dual battery-backed event counter that tracks the number of rising or falling edges detected on dedicated input pins.

Rev. 3.2 July 2010 Page 2 of 25 Pin Configuration Pin Name Function CNT1, CNT2 Event Counter Inputs A0, A1 Device Select inputs CAL/PFO Clock Calibration and Early Power-Fail Output /RST Reset Input/Output PFI Early Power-fail Input X1, X2 Crystal Connections SDA Serial Data SCL Serial Clock VBAK Battery-Backup Supply VDD Supply Voltage VSS Ground

Ordering Information

Base Configuration Memory Size Operating Voltage Reset Threshold Ordering Part Number Other memory configurations may be available. Please contact the factory for more information. VDD VBAK SCL SDA VSS CAL/PFO CNT1 PFIRST CNT2

Figure 1. Block Diagram contained in the device address. The device select pins are pulled down internally. should not be left floating. Tie to ground if pins are not used. calibration. In normal operation, this is the early power-fail output. X1 and a DC mid-level to X2 (see Crystal Oscillator section for suggestions). /RST I/O Active low reset output with weak pull-up. Also input for manual reset. open-drain and is intended to be wire-OR’d with other devices on the two-wire bus. driver includes slope control for falling edges. A pull-up resistor is required. Schmitt trigger input for noise immunity. an early power failure. This pin should not be left floating. supply is used, this pin should be left floating and the VBC bit should be set.

PFI edge, there is no hysteresis. application is not limited to the NMI function.

512 Hz square wave and the comparator will be

on system operations using the comparator. is limited to 3.75V under normal operating conditions. increment. CNT2 is not used in this mode. Figure 6. Event Counter is CC, bit 2; and the Read Counter bit is RC bit 3. pins are not being used, tie them to ground. still be read by the system. The serial number is located in registers 11h to 18h. registers, and the SNL bit cannot be cleared. calibration feature that allows high accuracy. diagram (Figure 7) illustrates the RTC function. Setting the W bit to 1 locks the user registers.

core occur continuously except when locked. exceeding the VBAK maximum voltage specification.

• For 3.3V systems, V BAK should be tied to V DD. This assumes VDD does not exceed 3.75V.
• For 5V systems, attach a 1 µF capacitor to V BAK and turn the trickle charger on. The V BAK pin will charge to the internal backup voltage which regulates itself to about 3.6V. V BAK should not be tied to 5V since the VBAK (max) specification will be exceeded. A 1 µF capacitor will keep the companion functions working for about 1.5 second. Although V BAK may be connected to V SS, this is not recommended if the companion is used. None of the companion functions will operate below about 2.5V. ,,,, Note: systems using lithium batteries should clear the VBC bit to 0 to prevent battery charging. The V BAK circuitry includes an internal 1 K Ω series resistor as a safety element.

Figure 7. Real-Time Clock Core Block Diagram

512 Hz W

1. When the CAL bit is 0, the CAL/PFO pin will

revert to the power fail output function. loading capacitors that match the crystal. operation, a DC bias must be applied to the X2 pin. Figure 8. External Oscillator with an inverted clock using a CMOS inverter.

Rev. 3.2 July 2010 Page 9 of 25 Calibration Adjustments Positive Calibration for slow clocks: Calibration will achieve ± 2.17 PPM after calibration Measured Frequency Range Error Range (PPM) Min Max Min Max Program Calibration Register to: 0 512.0000 511.9989 0 2.17 000000 1 511.9989 511.9967 2.18 6.51 100001 2 511.9967 511.9944 6.52 10.85 100010 3 511.9944 511.9922 10.86 15.19 100011 4 511.9922 511.9900 15.20 19.53 100100 5 511.9900 511.9878 19.54 23.87 100101 6 511.9878 511.9856 23.88 28.21 100110 7 511.9856 511.9833 28.22 32.55 100111 8 511.9833 511.9811 32.56 36.89 101000 9 511.9811 511.9789 36.90 41.23 101001 10 511.9789 511.9767 41.24 45.57 101010 11 511.9767 511.9744 45.58 49.91 101011 12 511.9744 511.9722 49.92 54.25 101100 13 511.9722 511.9700 54.26 58.59 101101 14 511.9700 511.9678 58.60 62.93 101110 15 511.9678 511.9656 62.94 67.27 101111 16 511.9656 511.9633 67.28 71.61 110000 17 511.9633 511.9611 71.62 75.95 110001 18 511.9611 511.9589 75.96 80.29 110010 19 511.9589 511.9567 80.30 84.63 110011 20 511.9567 511.9544 84.64 88.97 110100 21 511.9544 511.9522 88.98 93.31 110101 22 511.9522 511.9500 93.32 97.65 110110 23 511.9500 511.9478 97.66 101.99 110111 24 511.9478 511.9456 102.00 106.33 111000 25 511.9456 511.9433 106.34 110.67 111001 26 511.9433 511.9411 110.68 115.01 111010 27 511.9411 511.9389 115.02 119.35 111011 28 511.9389 511.9367 119.36 123.69 111100 29 511.9367 511.9344 123.70 128.03 111101 30 511.9344 511.9322 128.04 132.37 111110 31 511.9322 511.9300 132.38 136.71 111111 Negative Calibration for fast clocks: Calibration will achieve ± 2.17 PPM after calibration Measured Frequency Range Error Range (PPM) Min Max Min Max Program Calibration Register to: 0 512.0000 512.0011 0 2.17 000000 1 512.0011 512.0033 2.18 6.51 000001 2 512.0033 512.0056 6.52 10.85 000010 3 512.0056 512.0078 10.86 15.19 000011 4 512.0078 512.0100 15.20 19.53 000100 5 512.0100 512.0122 19.54 23.87 000101 6 512.0122 512.0144 23.88 28.21 000110 7 512.0144 512.0167 28.22 32.55 000111 8 512.0167 512.0189 32.56 36.89 001000 9 512.0189 512.0211 36.90 41.23 001001 10 512.0211 512.0233 41.24 45.57 001010 11 512.0233 512.0256 45.58 49.91 001011 12 512.0256 512.0278 49.92 54.25 001100 13 512.0278 512.0300 54.26 58.59 001101 14 512.0300 512.0322 58.60 62.93 001110 15 512.0322 512.0344 62.94 67.27 001111 16 512.0344 512.0367 67.28 71.61 010000 17 512.0367 512.0389 71.62 75.95 010001 18 512.0389 512.0411 75.96 80.29 010010 19 512.0411 512.0433 80.30 84.63 010011 20 512.0433 512.0456 84.64 88.97 010100 21 512.0456 512.0478 88.98 93.31 010101 22 512.0478 512.0500 93.32 97.65 010110 23 512.0500 512.0522 97.66 101.99 010111 24 512.0522 512.0544 102.00 106.33 011000 25 512.0544 512.0567 106.34 110.67 011001 26 512.0567 512.0589 110.68 115.01 011010 27 512.0589 512.0611 115.02 119.35 011011 28 512.0611 512.0633 119.36 123.69 011100 29 512.0633 512.0656 123.70 128.03 011101 30 512.0656 512.0678 128.04 132.37 011110 31 512.0678 512.0700 132.38 136.71 011111

Rev. 3.2 July 2010 Page 10 of 25 Register Map The RTC and processor companion functions are accessed via 25 special function registers mapped to a separate 2- wire device ID. The interface protocol is described below. The registers contain timekeeping data, control bits, or information flags. A description of each register follows the summary table below. Register Map Summary Table Nonvolatile = Battery-backed = Data Address D7 D6 D5 D4 D3 D2 D1 D0 Function Range Serial Number Byte 7 Serial Number 7 FFh Serial Number Byte 6 Serial Number 6 FFh Serial Number Byte 5 Serial Number 5 FFh Serial Number Byte 4 Serial Number 4 FFh Serial Number Byte 3 Serial Number 3 FFh Serial Number Byte 2 Serial Number 2 FFh Serial Number Byte 1 Serial Number 1 FFh Serial Number Byte 0 Serial Number 0 FFh 10h Counter 2 MSB Event Counter 2 MSB FFh 0Fh Counter 2 LSB Event Counter 2 LSB FFh 0Eh Counter 1 MSB Event Counter 1 MSB FFh 0Dh Counter 1 LSB Event Counter 1 LSB FFh 0Ch RC CC C2P C1P Event Count Control 0Bh SNL - - WP1 WP0 VBC VTP1 VTP0 Companion Control 0Ah WDE - - WDT4 WDT3 WDT2 WDT1 WDT0 Watchdo g Control 09h WTR POR LB - WR3 WR2 WR1 WR0 Watchdog Restart/Flags 08h 10 years years Years 00-99 07h 0 0 0 10 mo months Month 1-12 06h 00 10 date date Date 1-31 05h 00000 day Day 1-7 04h 00 10 hours hours Hours 0-23 03h 0 10 minutes minutes Minutes 0-59 02h 0 10 seconds seconds Seconds 0-59 01h /OSCEN reserved CALS CAL4 CAL3 CAL2 CAL1 CAL0 CAL/Control 00h reserved CF reserved reserved reserved CAL W R RTC Control 18h 17h 11h 16h 15h 14h 13h 12h Note: When the device is first powered up and programmed, all registers must be written because the battery- backed register values cannot be guaranteed. The table below shows the default values of the non-volatile registers. All other register values should be treated as unknown. Default Register Values Address Hex Value 18h 0x00 17h 0x00 16h 0x00 15h 0x00 14h 0x00 13h 0x00 12h 0x00 11h 0x00 0Bh 0x00 0Ah 0x1F 01h 0x80

Rev. 3.2 July 2010 Page 11 of 25 Register Description Address Description 18h Serial Number Byte 7 D7 D6 D5 D4 D3 D2 D1 D0 Upper byte of the serial number. Read/write when SNL=0, read-only when SNL=1. Nonvolatile. 17h Serial Number Byte 6 D7 D6 D5 D4 D3 D2 D1 D0 Byte 6 of the serial number. Read/write when SNL=0, read-only when SNL=1. Nonvolatile. 16h Serial Number Byte 5 D7 D6 D5 D4 D3 D2 D1 D0 Byte 5 of the serial number. Read/write when SNL=0, read-only when SNL=1. Nonvolatile. 15h Serial Number Byte 4 D7 D6 D5 D4 D3 D2 D1 D0 Byte 4 of the serial number. Read/write when SNL=0, read-only when SNL=1. Nonvolatile. 14h Serial Number Byte 3 D7 D6 D5 D4 D3 D2 D1 D0 Byte 3 of the serial number. Read/write when SNL=0, read-only when SNL=1. Nonvolatile. 13h Serial Number Byte 2 D7 D6 D5 D4 D3 D2 D1 D0 Byte 2 of the serial number. Read/write when SNL=0, read-only when SNL=1. Nonvolatile. 12h Serial Number Byte 1 D7 D6 D5 D4 D3 D2 D1 D0 Byte 1 of the serial number. Read/write when SNL=0, read-only when SNL=1. Nonvolatile. 11h Serial Number Byte 0 D7 D6 D5 D4 D3 D2 D1 D0 LSB of the serial number. Read/write when SNL=0, read-only when SNL=1. Nonvolatile. 10h Counter 2 MSB D7 D6 D5 D4 D3 D2 D1 D0 Event Counter 2 MSB. Increments on overflows from Counter 2 LSB. Battery-backed, read/write. 0Fh Counter 2 LSB D7 D6 D5 D4 D3 D2 D1 D0 Event Counter 2 LSB. Increments on programmed edge event on CNT2 input or overflows from Counter 1 MSB when CC=1. Battery-backed, read/write . 0Eh Counter 1 MSB D7 D6 D5 D4 D3 D2 D1 D0 Event Counter 1 MSB. Increments on overflows from Counter 1 LSB. Battery-backed, read/write. 0Dh Counter 1 LSB D7 D6 D5 D4 D3 D2 D1 D0 Event Counter 1 LSB. Increments on programmed edge event on CNT1 input. Battery-backed, read/write.

Rev. 3.2 July 2010 Page 12 of 25 0Ch Event Counter Control D7 D6 D5 D4 D3 D2 D1 D0 - - - - RC CC C2P C1P RC Read Counter. Setting this bit to 1 takes a snapshot of the four counters bytes allowing the system to read the values without missing count events. The RC bit will be automatically cleared. CC Counter Cascade. When CC=0, the event counters operate independently according to the edge programmed by C1P and C2P respectively. When CC=1, the counters are cascaded to create one 32-bit counter. The registers of Counter 2 represent the most significant 16-bits of the counter and CNT1 is the controlling input. Bit C2P is “don’t care” when CC=1. Battery-backed, read/write. C2P CNT2 detects falling edges when C2P = 0, rising edges when C2P = 1. C2P is “don’t care” when CC=1. The value of Event Counter 2 may inadvertently increment if C2P is changed. Battery-backed, read/write. C1P CNT1 detects falling edges when C1P = 0, rising edges when C1P = 1. The value of Event Counter 1 may inadvertently increment if C1P is changed. Battery-backed, read/write. 0Bh Companion Control D7 D6 D5 D4 D3 D2 D1 D0 SNL - - WP1 WP0 VBC VTP1 VTP0 SNL Serial Number Lock. Setting to a 1 makes registers 11h to 18h and SNL permanently read-only. SNL cannot be cleared once set to 1. Nonvolatile, read/write. WP1-0 Write Protect. These bits control the write protection of the memory array. Nonvolatile, read/write. Write protect addresses WP1 WP0 None 0 0 Bottom 1/4 0 1 Bottom 1/2 1 0 Full array 1 1 VBC VBAK Charger Control. Setting VBC to 1 causes a 15 µA trickle charge current to be supplied on VBAK. Clearing VBC to 0 disables the charge current. Nonvolatile, read/write. VTP1-0 VTP select. These bits control the reset trip point for the low VDD reset function. Nonvolatile, read/write. VTP VTP1 VTP0 2.6V 0 0 2.9V 0 1 3.9V 1 0 4.4V 1 1 0Ah Watchdog Control D7 D6 D5 D4 D3 D2 D1 D0 WDE - - WDT4 WDT3 WDT2 WDT1 WDT0 WDE Watchdog Enable. When WDE=1, a watchdog timer fault will cause the /RST signal to go active. When WDE = 0 the timer runs but has no effect on /RST, however the WTR flag will be set when a fault occurs. Note as the timer is free-running, users should restart the timer using WR3-0 prior to setting WDE=1. This assures a full watchdog timeout interval occurs. Nonvolatile, read/write. WDT4-0 Watchdog Timeout. Indicates the minimum watchdog timeout interval with 100 ms resolution. New watchdog timeouts are loaded when the timer is restarted by writing the 1010b pattern to WR3-0. Nonvolatile, read/write. Watchdog timeout WDT4 WDT3 WDT2 WDT1 WDT0 Invalid – default 100 ms 0 0 0 0 0 100 ms 0 0 0 0 1 200 ms 0 0 0 1 0 300 ms 0 0 0 1 1 . . 2000 ms 1 0 1 0 0 2100 ms 1 0 1 0 1 2200 ms 1 0 1 1 0 . . 2900 ms 1 1 1 0 1 3000 ms 1 1 1 1 0 Disable counter 1 1 1 1 1

Rev. 3.2 July 2010 Page 13 of 25 09h Watchdog Restart & Flags D7 D6 D5 D4 D3 D2 D1 D0 WTR POR LB - WR3 WR2 WR1 WR0 WTR Watchdog Timer Reset Flag: When a watchdog timer fault occurs, the WTR bit will be set to 1. It must be cleared by the user. Note that both WTR and POR could be set if both reset sources have occurred since the flags were cleared by the user. Battery-backed. Read/Write (internally set, user can clear bit). POR Power-on Reset Flag: When the /RST pin is activated by V DD < VTP, the POR bit will be set to 1. It must be cleared by the user. Note that both WTR and POR could be set if both reset sources have occurred since the flags were cleared by the user. Battery-backed. Read/Write (internally set, user can clear bit). LB Low Backup Flag: On power up, if the VBAK source is below the minimum voltage to operate the RTC and event counters, this bit will be set to 1. The user should clear it to 0 when initializing the system. Battery-backed. Read/Write (internally set, user can clear bit). WR3-0 Watchdog Restart: Writing a pattern 1010b to WR3-0 restarts the watchdog timer. The upper nibble contents do not affect this operation. Writing any pattern other than 1010b to WR3-0 has no effect on the timer. This allows users to clear the WTR, POR, and LB flags without affecting the watchdog timer. Battery-backed, Write-only. 08h Timekeeping – Years D7 D6 D5 D4 D3 D2 D1 D0 Contains the lower two BCD digits of the year. Lower nibble contains the value for years; upper nibble contains the value for 10s of years. Each nibble operates from 0 to 9. The range for the register is 0-99. Battery-backed, read/write. 07h Timekeeping – Months D7 D6 D5 D4 D3 D2 D1 D0 0 0 0 10 Month Month.3 Month.2 Month.1 Month.0 Contains the BCD digits for the month. Lower nibble contains the lower digit and operates from 0 to 9; upper nibble (one bit) contains the upper digit and operates from 0 to 1. The range for the register is 1-12. Battery- backed, read/write. 06h Timekeeping – Date of the month D7 D6 D5 D4 D3 D2 D1 D0 Contains the BCD digits for the date of the month. Lower nibble contains the lower digit and operates from 0 to 9; upper nibble contains the upper digit and operates from 0 to 3. The range for the register is 1-31. Battery-backed, read/write. 05h Timekeeping – Day of the week D7 D6 D5 D4 D3 D2 D1 D0 0 0 0 0 0 Day.2 Day.1 Day.0 Lower nibble contains a value that correlates to day of the week. Day of the week is a ring counter that counts from 1 to 7 then returns to 1. The user must assign meaning to the day value, as the day is not integrated with the date. Battery-backed, read/write. 04h Timekeeping – Hours D7 D6 D5 D4 D3 D2 D1 D0 Contains the BCD value of hours in 24-hour format. Lower nibble contains the lower digit and operates from 0 to 9; upper nibble (two bits) contains the upper digit and operates from 0 to 2. The range for the register is 0-23. Battery-backed, read/write. 03h Timekeeping – Minutes D7 D6 D5 D4 D3 D2 D1 D0 Contains the BCD value of minutes. Lower nibble contains the lower digit and operates from 0 to 9; upper nibble contains the upper minutes digit and operates from 0 to 5. The range for the register is 0-59. Battery-backed, read/write. 02h Timekeeping – Seconds D7 D6 D5 D4 D3 D2 D1 D0 Contains the BCD value of seconds. Lower nibble contains the lower digit and operates from 0 to 9; upper nibble contains the upper digit and operates from 0 to 5. The range for the register is 0-59. Battery-backed, read/write.

Rev. 3.2 July 2010 Page 14 of 25 01h CAL/Control D7 D6 D5 D4 D3 D2 D1 D0 /OSCEN /Oscillator Enable. When set to 1, the oscillator is halted. When set to 0, the oscillator runs. Disabling the oscillator can save battery power during storage. On a power-up without battery, this bit is set to 1. Battery- backed, read/write. Reserved Reserved bits. Do not use. Should remain set to 0. CALS Calibration sign. Determines if the calibration adjustment is applied as an addition to or as a subtraction from the time-base. Calibration is explained on page 7. Nonvolatile, read/write. CAL.4-0 These five bits control the calibration of the clock. Nonvolatile, read/write. 00h Flags/Control D7 D6 D5 D4 D3 D2 D1 D0 Reserved CF Reserved Reserved Reserved CAL W R CF Century Overflow Flag. This bit is set to a 1 when the values in the years register overflows from 99 to 00. This indicates a new century, such as going from 1999 to 2000 or 2099 to 2100. The user should record the new century information as needed. This bit is cleared to 0 when the Flag register is read. It is read-only for the user. Battery-backed. CAL Calibration Mode. When set to 1, the clock enters calibration mode. When CAL is set to 0, the clock operates normally, and the CAL/PFO pin is controlled by the power fail comparator. Battery-backed, read/write. W Write Time. Setting the W bit to 1 freezes the clock. The user can then write the timekeeping registers with updated values. Resetting the W bit to 0 causes the contents of the time registers to be transferred to the timekeeping counters and restarts the clock. Battery-backed, read/write. R Read Time. Setting the R bit to 1 copies a static image of the timekeeping core and place it into the user registers. The user can then read them without concerns over changing values causing system errors. The R bit going from 0 to 1 causes the timekeeping capture, so the bit must be returned to 0 prior to reading again. Battery-backed, read/write. Reserved Reserved bits. Do not use. Should remain set to 0.

Slave Address (Slave ID = 1101b). in the Electrical Specifications section. Figure 9. Data Transfer Protocol aborted by asserting a Start condition at any time. ready the FM31xx for a new operation. condition prior to performing another operation. high. All operations must end with a Stop condition. not change while SCL is high. data bit has been transferred in any transaction. (NACK) and the operation is aborted. The receiver might NACK for two distinct reasons. recovered in the event of a communication error. send an ACK to deliberately terminate an operation. master is sending a new command such as a Stop.

Rev. 3.2 July 2010 Page 20 of 25 Electrical Specifications Absolute Maximum Ratings Symbol Description Ratings VDD Power Supply Voltage with respect to V SS -1.0V to +7.0V VIN Voltage on any signal pin with respect to V SS -1.0V to +7.0V * and VIN ≤ VDD+1.0V ** VBAK Backup Supply Voltage -1.0V to +4.5V TSTG Storage Temperature -55°C to + 125°C TLEAD Lead Temperature (Soldering, 10 seconds) 260° C VESD Electrostatic Discharge Voltage - Human Body Model (JEDEC Std JESD22-A114-B) - Charged Device Model (JEDEC Std JESD22-C101-A) - Machine Model (JEDEC Std JESD22-A115-A) 4kV 1kV 250V Package Moisture Sensitivity Level MSL-1 * PFI input voltage must not exceed 4.5V. ** The “VIN < VDD+1.0V” restriction does not apply to the SCL and SDA inputs which do not employ a diode to VDD. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating on ly, and the functional operation of the device at these or any other conditions above those listed in the operational section of th is specification is not implied. Exposure to absolute maximum ratings conditions for extended periods may affect device reliability. DC Operating Conditions (TA = -40° C to + 85° C, VDD = 2.7V to 5.5V unless otherwise specified) Symbol Parameter Min Typ Max Units Notes VDD Main Power Supply 2.7 5.5 V 7 IDD V DD Supply Current @ SCL = 100 kHz @ SCL = 400 kHz @ SCL = 1 MHz 500 900 1500 µA µA µA ISB Standby Current For VDD < 5.5V For VDD < 3.6V 150 120 µA µA VBAK RTC Backup Supply Voltage 2.0 3.0 3.75 V 9 IBAK RTC Backup Supply Current 1 µA 4 IBAKTC Trickle Charge Current 5 25 µA 10 VTP0 V DD Trip Point Voltage, VTP(1:0) = 00b 2.55 2.6 2.70 V 5 VTP1 V DD Trip Point Voltage, VTP(1:0) = 01b 2.85 2.9 3.00 V 5 VTP2 V DD Trip Point Voltage, VTP(1:0) = 10b 3.80 3.9 4.00 V 5 VTP3 V DD Trip Point Voltage, VTP(1:0) = 11b 4.25 4.4 4.50 V 5 VRST VDD for valid /RST @ IOL = 80 µA at VOL VBAK > VBAK min VBAK < VBAK min 1.6 V V ILI Input Leakage Current ±1 µA 3 ILO Output Leakage Current ±1 µA 3 VIL Input Low Voltage All inputs except those listed below CNT1-2 battery backed (V DD < 2.5V) CNT1-2 (VDD > 2.5V) -0.3 -0.3 -0.3 0.3 V DD 0.5 0.8 V V V VIH Input High Voltage All inputs except those listed below PFI (comparator input) CNT1-2 battery backed (VDD < 2.5V) CNT1-2 VDD > 2.5V

0.7 VDD

VBAK – 0.5 VDD + 0.3 3.75 VBAK + 0.3 VDD + 0.3 V V V V VOL Output Low Voltage (I OL = 3 mA) - 0.4 V VOH Output High Voltage (I OH = -2 mA) 2.4 - V RRST Pull-up Resistance for /RST Inactive 50 400 KΩ Continued »

Rev. 3.2 July 2010 Page 21 of 25 DC Operating Conditions, continued (TA = -40° C to + 85° C, VDD = 2.7V to 5.5V unless otherwise specified) Symbol Parameter Min Typ Max Units Notes RIN Input Resistance (pulldown) A1-A0 for VIN = VIL max A1-A0 for VIN = VIH min KΩ MΩ VPFI Power Fail Input Reference Voltage 1.175 1.20 1.225 V VHYS Power Fail Input (PFI) Hysteresis (Rising) - 100 mV Notes 1. SCL toggling between VDD-0.3V and VSS, other inputs VSS or VDD-0.3V. 2. All inputs at VSS or VDD, static. Stop command issued. 3. VIN or VOUT = VSS to VDD. Does not apply to A0, A1, PFI, or /RST pins. 4. VBAK = 3.0V, VDD < 2.4V, oscillator running, CNT1-2 at VBAK. 5. /RST is asserted low when VDD < VTP. 6. The minimum VDD to guarantee the level of /RST remains a valid VOL level. 7. Full complete operation. Supervisory circuits, RTC, etc operate to lower voltages as specified. 8. Includes /RST input detection of external reset condition to trigger driving of /RST signal by FM31xx. 9. The VBAK trickle charger automatically regulates the maximum voltage on this pin for capacitor backup applications. 10. VBAK will source current when trickle charge is enabled (VBC bit=1), VDD > VBAK, and VBAK < VBAK max. AC Parameters (TA = -40° C to + 85° C, VDD = 2.7V to 5.5V, CL = 100 pF unless otherwise specified) Symbol Parameter Min Max Min Max Min Max Units Notes fSCL SCL Clock Frequency 0 100 0 400 0 1000 kHz tLOW Clock Low Period 4.7 1.3 0.6 µs tHIGH Clock High Period 4.0 0.6 0.4 µs tAA SCL Low to SDA Data Out Valid 3 0.9 0.55 µs tBUF Bus Free Before New Transmission 4.7 1.3 0.5 µs tHD:STA Start Condition Hold Time 4.0 0.6 0.25 µs tSU:STA Start Condition Setup for Repeated Start 4.7 0.6 0.25 µs tHD:DAT Data In Hold Time 0 0 0 ns tSU:DAT Data In Setup Time 250 100 100 ns tR Input Rise Time 1000 300 300 ns 1 tF Input Fall Time 300 300 100 ns 1 tSU:STO Stop Condition Setup Time 4.0 0.6 0.25 µs tDH Data Output Hold (from SCL @ VIL) 0 0 0 ns tSP Noise Suppression Time Constant on SCL, SDA 50 50 50 ns All SCL specifications as well as start and stop conditions apply to both read and write operations. Capacitance (TA = 25° C, f=1.0 MHz, VDD = 3.0V) Symbol Parameter Typ Max Units Notes CIO Input/Output Capacitance - 8 pF 1 CXTAL X1, X2 Crystal pin Capacitance 12 - pF 1, 2 Notes 1 This parameter is characterized but not tested. 2 The crystal attached to the X1/X2 pins must be rated as 6pF. Data Retention (TA = -40° C to + 85° C, VDD = 2.7V to 5.5V) Parameter Min Units Notes Data Retention 10 Years

Rev. 3.2 July 2010 Page 22 of 25 Supervisor Timing (TA = -40° C to + 85° C, VDD = 2.7V to 5.5V) Symbol Parameter Min Max Units Notes tRPU /RST Active (low) after V DD>VTP 100 200 ms tRNR V DD < VTP noise immunity 10 25 µs 1 tVR V DD Rise Time 50 - µs/V 1,2 tVF V DD Fall Time 100 - µs/V 1,2 tWDP Pulse Width of /RST for Watchdog Reset 100 200 ms tWDOG Timeout of Watchdog t DOG 2*t DOG ms 3 fCNT Frequency of Event Counters 0 10 MHz Notes 1 This parameter is characterized but not tested. 2 Slope measured at any point on VDD waveform. 3 tDOG is the programmed time in register 0Ah, VDD > VTP and tRPU satisfied. /RST Timing VDD VTP VRST RST tRPU tRNR

Rev. 3.2 July 2010 Page 23 of 25 AC Test Conditions Equivalent AC Load Circuit Input Pulse Levels 0.1 V DD to 0.9 VDD Input rise and fall times 10 ns Input and output timing levels 0.5 V DD Diagram Notes All start and stop timing parameters apply to both read and write cycles. Clock specifications are identical for read and write cycles. Write timing parameters apply to slave address, word address, and write data bits. Functional relationships are illustrated in the relevant data sheet sections. These diagrams illustrate the timing parameters only. Read Bus Timing t SU:STA Start tR tF Stop Start tBUF tHIGH 1/fSCL tLOW tSP t SP Acknowledge tHD:DAT tSU:DAT tAA tDH SCL SDA Write Bus Timing tSU:STO Start Stop Start Acknowledge tAA tHD:DAT tHD:STA tSU:DAT SCL SDA 5.5V Output 1700 Ω 100 pF

Rev. 3.2 July 2010 Page 24 of 25 Mechanical Drawing 14-pin SOIC (JEDEC Standard MS-012 variation AB) Pin 1 3.90 ±0.13 6.00 ±0.20 8.64 ±0.10 0.10 0.25 1.35 1.75 0.33 0.51 1.27 0.10 mm 0.25 0.50 45 ° 0.40 1.27 0.19 0.25 0°-8 ° Recommended PCB Footprint 7.70 0.651.27 2.00 3.70 . . . . . . Refer to JEDEC MS-012 for complete dimensions and notes. All dimensions in millimeters Legend: XXXX= part number, P= package type (G=”Green”/RoHS) LLLLLLL= lot code RIC=Ramtron Int’l Corp, YY=year, WW=work week Example: FM31256, “Green” SOIC package, Year 2009, Work Week 42 FM31256-G B90007G1 RIC 0942 XXXXXXX-P LLLLLLL RIC YYWW

Rev. 3.2 July 2010 Page 25 of 25

Revision History

0.2 5/22/03 Initial release. 0.21 11/25/03 Fixed package drawing dimensions. 1.0 3/30/04 Changed product status to Preliminary. Added V TP and V PFI parameters in DC Operating table. Changed VHYS limits. Added “green” package. 1.0a 4/27/04 Changed V PFI limits, changed V TF and V TR conditions and measurement units, created additional ISB specification, and added board layout section. 2.0 10/25/04 Changed to Pre-Production status. Added text to Trickle Charger section. Improved spec limits on V TP, VPFI, and VHYS parameters and changed V IH max limits in DC Operating table. Added companion register table with default values. Added Package Marking Scheme and board footprint. Devices marked with Date Codes 0440 and higher comply with the revision of the datasheet. 2.1 12/8/04 Changed description of POR flag and manual reset (pg. 5, 13). Added notes to Absolute Maximum Ratings. 2.2 11/2/05 Rewrote section on battery backup. Added comment about unused CNT pins. 2.3 10/2/06 Removed –S packaging option which is Not Recommended for New Designs. Added ESD and MSL ratings which are valid for Date Codes 0440 and higher. 2.4 2/6/2008 Not recommended for new designs. As an alternative, use FM3127xB for 5V designs or FM31L27xB for 3V designs. 3.0 2/16/2010 Changed to Production status. These products are no longer Not Recommended for New Designs (NRND). Updated ESD ratings. Updated lead temperature rating in Abs Max table. 3.1 3/23/2010 Removed battery insertion sequence text (p. 7). The sequence is no longer necessary for devices with date codes after 0701. 3.2 7/27/2010 Removed text indicating that a manual reset sets the POR flag.