FM25L16B-G

FM25L16B RAMTRON | Alldatasheet

Document overview

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• PDF pages: 14

Technical content

Features

16K bit Ferroelectric Nonvolatile RAM

• Organized as 2,048 x 8 bits
• High Endurance 100 Trillion (1014) Read/Writes
• 38 Year Data Retention (@ +75ºC)
• NoDelay™ Writes
• Advanced High-Reliability Ferroelectric Process Very Fast Serial Peripheral Interface - SPI
• Up to 20 MHz Frequency
• Direct Hardware Replacement for EEPROM
• SPI Mode 0 & 3 (CPOL, CPHA=0,0 & 1,1) Sophisticated Write Protection Scheme
• Hardware Protection
• Software Protection Low Power Consumption
• Low Voltage Operation 2.7-3.6V
• 200 µA Active Current (1 MHz)
• 3 µA (typ.) Standby Current Industry Standard Configuration
• Industrial Temperature -40°C to +85°C
• 8-pin “Green”/RoHS SOIC and TDFN Packages

Description

The FM25L16B is a 16-kilobit nonvolatile memory employing an advanced ferroelectric process. A ferroelectric random access memory or F-RAM is nonvolatile and performs reads and writes like a RAM. It provides reliable data retention for 38 years while eliminating the complexities, overhead, and system level reliability problems caused by EEPROM and other nonvolatile memories. The FM25L16B performs write operations at bus speed. No write delays are incurred. Data is written to the memory array immediately after each byte has been transferred to the device. The next bus cycle may commence without the need for data polling. The FM25L16B is capable of supporting 10 read/write cycles, or a million times more write cycles than EEPROM. These capabilities make the FM25L16B ideal for nonvolatile memory applications requiring frequent or rapid writes. Examples range from data collection, where the number of write cycles may be critical, to demanding industrial controls where the long write time of EEPROM can cause data loss. The FM25L16B provides substantial benefits to users of serial EEPROM as a hardware drop-in replacement. The FM25L16B uses the high-speed SPI bus, which enhances the high-speed write capability of F-RAM technology. Device specifications are guaranteed over an industrial temperature range of -40°C to +85°C. Pin Configuration Pin Name Function /CS Chip Select /WP Write Protect /HOLD Hold SCK Serial Clock SI Serial Data Input SO Serial Data Output VDD Supply Voltage VSS Ground

Ordering Information

FM25L16B-G “Green”/RoHS 8-pin SOIC FM25L16B-GTR “Green”/RoHS 8-pin SOIC, Tape & Reel FM25L16B-DG “Green”/RoHS 8-pin TDFN FM25L16B-DGTR “Green”/RoHS 8-pin TDFN, Tape & Reel /CS SO /WP VSS VDD /HOLD SCK SI Top View CS SO WP VSS VDD HOLD SCK SI

Figure 1. Block Diagram register. A complete explanation of write protection is provided on pages 6 and 7. logic level to meet IDD specifications.

• SI may be connected to SO for a single pin data interface.

the falling edge of the serial clock.

• SO may be connected to SI for a single pin data interface.

FM25L16B - 16Kb 3V SPI F-RAM Rev. 1.3 Mar. 2011 Page 3 of 14 Overview The FM25L16B is a serial F-RAM memory. The memory array is logically organized as 2,048 x 8 and is accessed using an industry standard Serial Peripheral Interface or SPI bus. Functional operation of the F-RAM is similar to serial EEPROMs. The major difference between the FM25L16B and a serial EEPROM with the same pinout is the F-RAM’s superior write performance. Memory Architecture When accessing the FM25L16B, the user addresses 2,048 locations of 8 data bits each. These data bits are shifted serially. The addresses are accessed using the SPI protocol, which includes a chip select (to permit multiple devices on the bus), an op-code, and a two-byte address. The upper 5 bits of the address range are ‘don’t care’ values. The complete address of 11-bits specifies each byte address uniquely. Most functions of the FM25L16B either are controlled by the SPI interface or are handled automatically by on-board circuitry. The access time for memory operation is essentially zero, beyond the time needed for the serial protocol. That is, the memory is read or written at the speed of the SPI bus. Unlike an EEPROM, it is not necessary to poll the device for a ready condition since writes occur at bus speed. So, by the time a new bus transaction can be shifted into the device, a write operation will be complete. This is explained in more detail in the interface section. Users expect several obvious system benefits from the FM25L16B due to its fast write cycle and high endurance as compared with EEPROM. In addition there are less obvious benefits as well. For example in a high noise environment, the fast-write operation is less susceptible to corruption than an EEPROM since it is completed quickly. By contrast, an EEPROM requiring milliseconds to write is vulnerable to noise during much of the cycle. Note that the FM25L16B contains no power management circuits other than a simple internal power-on reset. It is the user’s responsibility to ensure that V DD is within datasheet tolerances to prevent incorrect operation. It is recommended that the part is not powered down with chip select active. Serial Peripheral Interface – SPI Bus The FM25L16B employs a Serial Peripheral Interface (SPI) bus. It is specified to operate at speeds up to 20 MHz. This high-speed serial bus provides high performance serial communication to a host microcontroller. Many common microcontrollers have hardware SPI ports allowing a direct interface. It is quite simple to emulate the port using ordinary port pins for microcontrollers that do not. The FM25L16B operates in SPI Mode 0 and 3. The SPI interface uses a total of four pins: clock, data-in, data-out, and chip select. A typical system configuration uses one or more FM25L16B devices with a microcontroller that has a dedicated SPI port, as Figure 2 illustrates. Note that the clock, data-in, and data-out pins are common among all devices. The Chip Select and Hold pins must be driven separately for each FM25L16B device. For a microcontroller that has no dedicated SPI bus, a general purpose port may be used. To reduce hardware resources on the controller, it is possible to connect the two data pins (SI, SO) together and tie off (high) the Hold pin. Figure 3 shows a configuration that uses only three pins. Protocol Overview The SPI interface is a synchronous serial interface using clock and data pins. It is intended to support multiple devices on the bus. Each device is activated using a chip select. Once chip select is activated by the bus master, the FM25L16B will begin monitoring the clock and data lines. The relationship between the falling edge of /CS, the clock and data is dictated by the SPI mode. The device will make a determination of the SPI mode on the falling edge of each chip select. While there are four such modes, the FM25L16B supports Modes 0 and 3. Figure 4 shows the required signal relationships for Modes 0 and 3. For both modes, data is clocked into the FM25L16B on the rising edge of SCK and data is expected on the first rising edge after /CS goes active. If the clock begins from a high state, it will fall prior to beginning data transfer in order to create the first rising edge. The SPI protocol is controlled by op-codes. These op-codes specify the commands to the device. After /CS is activated the first byte transferred from the bus master is the op-code. Following the op-code, any addresses and data are then transferred. Note that the WREN and WRDI op-codes are commands with no subsequent data transfer. Important: The /CS must go inactive (high) after an operation is complete and before a new op-code can be issued. There is one valid op-code only per active chip select.

protect inadvertent changes to the block protect bits. Register is write protected if WPEN=1 and /WP=0. write protection conditions. Table 4. Write Protection

0 X X Protected Protected Protected

any number of sequential writes may be performed. op-code. The next op-code is the WRITE instruction. operation is shown in Figure 10. but the SCK pin can toggle during a hold state.

FM25L16B - 16Kb 3V SPI F-RAM Rev. 1.3 Mar. 2011 Page 9 of 14 Electrical Specifications Absolute Maximum Ratings Symbol Description Ratings VDD Power Supply Voltage with respect to V SS -1.0V to +5.0V VIN Voltage on any pin with respect to V SS -1.0V to +5.0V and VIN < VDD+1.0V TSTG Storage Temperature -55°C to + 125°C TLEAD Lead Temperature (Soldering, 10 seconds) 260° C VESD Electrostatic Discharge Voltage - Human Body Model (AEC-Q100-002 Rev. E) - Charged Device Model (AEC-Q100-011 Rev. B) - Machine Model (AEC-Q100-003 Rev. E) 4kV 1.25kV 300V Package Moisture Sensitivity Level MSL-1 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only, and the functional operation of the device at these or any other conditions above those listed in the operational section of this 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 3.6V unless otherwise specified) Symbol Parameter Min Typ Max Units Notes VDD Power Supply Voltage 2.7 3.3 3.6 V IDD VDD Supply Current @ SCK = 1.0 MHz @ SCK = 20.0 MHz 0.2 3.0 mA mA ISB Standby Current - 3 6 µA 2 ILI Input Leakage Current - ±1 µA 3 ILO Output Leakage Current - ±1 µA 3 VIH Input High Voltage 0.7 V DD V DD + 0.3 V VIL Input Low Voltage -0.3 0.3 V DD V VOH Output High Voltage @ IOH = -2 mA VDD – 0.8 - V VOL Output Low Voltage @ IOL = 2 mA - 0.4 V VHYS Input Hysteresis 0.05 VDD - V 4 Notes 1. SCK toggling between VDD-0.3V and VSS, other inputs VSS or VDD-0.3V. 2. SCK = SI = /CS=VDD. All inputs VSS or VDD. 3. VSS ≤ VIN ≤ VDD and VSS ≤ VOUT ≤ VDD. 4. Characterized but not 100% tested in production. Applies only to /CS and SCK pins.

FM25L16B - 16Kb 3V SPI F-RAM Rev. 1.3 Mar. 2011 Page 10 of 14 AC Parameters (TA = -40° C to + 85° C, CL = 30pF, VDD = 2.7V to 3.6V unless otherwise specified) Symbol Parameter Min Max Units Notes fCK SCK Clock Frequency 0 20 MHz tCH Clock High Time 22 ns 1 tCL Clock Low Time 22 ns 1 tCSU Chip Select Setup 10 ns tCSH Chip Select Hold 10 ns tOD Output Disable Time 20 ns 2 tODV Output Data Valid Time 20 ns tOH Output Hold Time 0 ns tD Deselect Time 60 ns tR Data In Rise Time 50 ns 2,3 tF Data In Fall Time 50 ns 2,3 tSU Data Setup Time 5 ns tH Data Hold Time 5 ns tHS /HOLD Setup Time 10 ns tHH /HOLD Hold Time 10 ns tHZ /HOLD Low to Hi-Z 20 ns 2 tLZ /HOLD High to Data Active 20 ns 2 Notes 1. tCH + tCL = 1/fCK. 2. Characterized but not 100% tested in production. 3. Rise and fall times measured between 10% and 90% of waveform. Capacitance (TA = 25° C, f=1.0 MHz, VDD = 3.3V) Symbol Parameter Min Max Units Notes CO Output Capacitance (SO) - 8 pF 1 CI Input Capacitance - 6 pF 1 Notes 1. This parameter is periodically sampled and not 100% tested. 2. Slope measured at any point on VDD waveform. AC Test Conditions Input Pulse Levels 10% and 90% of V DD Input rise and fall times 5 ns Input and output timing levels 0.5 V DD Output Load Capacitance 30 pF Data Retention Symbol Parameter Min Max Units Notes TDR @ +85ºC 10 - Years @ +80ºC 19 - Years @ +75ºC 38 - Years

FM25L16B - 16Kb 3V SPI F-RAM Rev. 1.3 Mar. 2011 Page 11 of 14 Serial Data Bus Timing /Hold Timing CS SCK SO HOLD tHS tHH tHZ tLZ tHS tHH Power Cycle Timing Power Cycle Timing (TA = -40° C to + 85° C, VDD = 2.7V to 3.6V unless otherwise specified) Symbol Parameter Min Max Units Notes tPU V DD(min) to First Access Start 10 - ms tPD Last Access Complete to V DD(min) 0 - µs tVR V DD Rise Time 30 - µs/V 1 tVF V DD Fall Time 100 - µs/V 1 Notes 1. Slope measured at any point on VDD waveform.

FM25L16B - 16Kb 3V SPI F-RAM Rev. 1.3 Mar. 2011 Page 12 of 14 Mechanical Drawing 8-pin SOIC (JEDEC Standard MS-012, variation AA) Pin 1 4.90 ±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: XXXXXX= part number, P= package type (G=SOIC) R=rev code, LLLLLLL= lot code RIC=Ramtron Int’l Corp, YY=year, WW=work week Example: FM25L16B, “Green” SOIC package, Year 2010, Work Week 47 FM25L16B-G A00002G1 RIC1047 XXXXXXX-P RLLLLLLL RICYYWW

FM25L16B - 16Kb 3V SPI F-RAM Rev. 1.3 Mar. 2011 Page 13 of 14 8-pin TDFN (4.0mm x 4.5mm body, 0.95mm pitch) Pin 1 4.00 ±0.1 4.50 ±0.1 0.75 ±0.05 0.40 ±0.05 0.95 0.20 REF. Pin 1 ID 0.0 - 0.05

2.85 REF

3.60 ±0.10 2.60 ±0.10 Exposed metal pad should be left floating. 4.30 0.45 0.95 Recommended PCB Footprint 0.60 0.30 ±0.1 Note: All dimensions in millimeters. The exposed pad should be left floating. Legend: R=Ramtron, G=”green” TDFN package, XXXX=base part number LLLL= lot code YY=year, WW=work week Example: “Green”/RoHS TDFN package, FM25L16B, Lot 0003, Year 2011, Work Week 07 R5L16B 0003 1107 RGXXXX LLLL YYWW

FM25L16B - 16Kb 3V SPI F-RAM Rev. 1.3 Mar. 2011 Page 14 of 14

Revision History

1.0 11/10/2010 Initial Release 1.1 12/15/2010 Added 4x4.5mm DFN package. Fixed endurance section on pg 8. 1.2 2/15/2011 Updated DFN package marking. Changed t PU and tVF spec limits. 1.3 3/22/2011 Added ESD ratings.