Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsIntegrated Circuits (ICs)TSOC 6 1 kBit 256 x 4

General Description

The DS2431-A1 is an AEC-Q100 Grade 1 qualified ver-

sion of the DS2431. The logical behavior of both ver-

sions is identical. The DS2431-A1 is a 1024-bit, 1-Wire

EEPROM chip organized as four memory pages of 256

bits each. Data is written to an 8-byte scratchpad, veri-

fied, and then copied to the EEPROM memory. As a

special feature, the four memory pages can individually

be write protected or put in EPROM-emulation mode,

where bits can only be changed from a 1 to a 0 state.

The DS2431-A1 communicates over the single-conduc-

tor 1-Wire bus. The communication follows the standard

1-Wire protocol. Each device has its own unalterable

and unique 64-bit ROM registration number that is fac-

tory lasered into the chip. The registration number is

used to address the device in a multidrop 1-Wire net

environment.

Applications

Automotive Sensor Identification and Calibration

Data Storage

Automotive Cable Assembly Identification

Accessory/PCB Identification

Features

♦ 1024 Bits of EEPROM Memory Partitioned Into

Four Pages of 256 Bits

♦ Individual Memory Pages Can Be Permanently

Write Protected or Put in EPROM-Emulation Mode

(“Write to 0”)

♦ Switchpoint Hysteresis and Filtering to Optimize

Performance in the Presence of Noise

♦ IEC 1000-4-2 Level 4 ESD Protection (+8kV

Contact, +15kV Air, Typ)

♦ Reads and Writes Over a 4.5V to 5.25V Voltage

Range from -40°C to +125°C

♦ Communicates to Host with a Single Digital

Signal at 15.4kbps Using 1-Wire Protocol

♦ Meets AEC-Q100 Grade 1 Qualification

Requirements

♦ Also Available as Standard Version for Industrial

Temperature Range (DS2431)

DS2431-A1

1024-Bit, 1-Wire EEPROM

for Automotive Applications

________________________________________________________________

Maxim Integrated Products

N.C.

I/O

GND

N.C.

TSOC

TOP VIEW

DS2431-A1

Pin Configuration

Ordering Information

DS2431-A1

I/O

PUP

μC

GND

Typical Operating Circuit

Rev 1; 3/08

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

PART TEMP RANGE PIN-PACKAGE

DS2431P-A1+ -40°C to +125°C 6 TSOC

DS2431P-A1+T -40°C to +125°C 6 TSOC

Commands and modes are capitalized for clarity.

1-Wire is a registered trademark of Maxim Integrated Products, Inc.

Summary of content (21 pages)

PAGE 1
Rev 1; 3/08 1024-Bit, 1-Wire EEPROM for Automotive Applications The DS2431-A1 is an AEC-Q100 Grade 1 qualified version of the DS2431. The logical behavior of both versions is identical. The DS2431-A1 is a 1024-bit, 1-Wire® EEPROM chip organized as four memory pages of 256 bits each. Data is written to an 8-byte scratchpad, verified, and then copied to the EEPROM memory.
PAGE 2
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications ABSOLUTE MAXIMUM RATINGS I/O Voltage to GND .....................................................-0.5V, +6V I/O Sink Current ..................................................................20mA Operating Temperature Range .........................-40°C to +125°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-55°C to +125°C Soldering Temperature ........
PAGE 3
1024-Bit, 1-Wire EEPROM for Automotive Applications Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: Note 10: Note 11: Note 12: Note 13: Note 14: Note 15: Note 16: Note 17: Note 18: Note 19: Note 20: Note 21: Note 22: Note 23: Note 24: Specifications at TA = -40°C are guaranteed by design only and not production tested. System requirement. Maximum allowable pullup resistance is a function of the number of 1-Wire devices in the system and 1-Wire recovery times.
PAGE 4
1024-Bit, 1-Wire EEPROM for Automotive Applications DS2431-A1 Pin Description PIN NAME 1 GND 2 I/O 3–6 N.C. FUNCTION Ground Reference 1-Wire Bus Interface. Open drain, requires external pullup resistor. No Connection Detailed Description The DS2431-A1 combines 1024 bits of EEPROM, an 8-byte register/control page with up to seven user read/write bytes, and a fully featured 1-Wire interface in a single chip.
PAGE 5
1024-Bit, 1-Wire EEPROM for Automotive Applications 1-Wire ROM FUNCTION COMMANDS (SEE FIGURE 9) DS2431-A1-SPECIFIC MEMORY FUNCTION COMMANDS (SEE FIGURE 7) AVAILABLE COMMANDS: DATA FIELD AFFECTED: READ ROM MATCH ROM SEARCH ROM SKIP ROM RESUME 64-BIT REG. #, RC-FLAG 64-BIT REG. #, RC-FLAG 64-BIT REG.
PAGE 6
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications POLYNOMIAL = X8 + X5 + X4 + 1 1ST STAGE X0 2ND STAGE X1 3RD STAGE X2 4TH STAGE 5TH STAGE X3 6TH STAGE X4 X5 7TH STAGE X6 8TH STAGE X7 X8 INPUT DATA Figure 4. 1-Wire CRC Generator Memory Data memory and registers are located in a linear address space, as shown in Figure 5. The data memory and the registers have unrestricted read access. The DS2431-A1 EEPROM array consists of 18 rows of 8 bytes each.
PAGE 7
1024-Bit, 1-Wire EEPROM for Automotive Applications The copy protection byte is used for a higher level of security, and should only be used after all other protection control bytes, user bytes, and write-protected pages are set to their final value. If the copy protection byte is set to 55h or AAh, all copy attempts to the register row and user byte row are blocked. In addition, all copy attempts to write-protected main memory pages (i.e., refresh) are blocked.
PAGE 8
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications the three LSBs of the target address (T2, T1, T0) must be equal to 000b. If T2:T0 are sent with nonzero values, the copy function is blocked. Under certain conditions (see the Write Scratchpad [0Fh] section) the master receives an inverted CRC-16 of the command, address (actual address sent), and data at the end of the Write Scratchpad command sequence.
PAGE 9
1024-Bit, 1-Wire EEPROM for Automotive Applications 0Fh WRITE SCRATCHPAD? AAh READ SCRATCHPAD? N Y DS2431-A1 SETS SCRATCHPAD BYTE COUNTER = T2:T0 MASTER Tx DATA BYTE TO SCRATCHPAD APPLIES ONLY IF THE MEMORY AREA IS NOT PROTECTED.
PAGE 10
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications FROM FIGURE 7 1ST PART 55h COPY SCRATCHPAD? Y Y T15:T0 < 0090h? N Y APPLICABLE TO ALL R/W MEMORY LOCATIONS. BUS MASTER Tx TA1 (T7:T0), TA2 (T15:T8) AND E/S BYTE AUTH.
PAGE 11
1024-Bit, 1-Wire EEPROM for Automotive Applications Copy Scratchpad [55h] The Copy Scratchpad command is used to copy data from the scratchpad to writable memory sections. After issuing the Copy Scratchpad command, the master must provide a 3-byte authorization pattern, which should have been obtained by an immediately preceding Read Scratchpad command. This 3-byte pattern must exactly match the data contained in the three address registers (TA1, TA2, E/S, in that order).
PAGE 12
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications VPUP BUS MASTER DS2431-A1 1-Wire PORT RPUP DATA Rx Tx Rx = RECEIVE Tx = TRANSMIT OPEN-DRAIN PORT PIN Rx IL Tx 100Ω MOSFET Figure 8. Hardware Configuration Initialization Search ROM [F0h] All transactions on the 1-Wire bus begin with an initialization sequence. The initialization sequence consists of a reset pulse transmitted by the bus master followed by presence pulse(s) transmitted by the slave(s).
PAGE 13
1024-Bit, 1-Wire EEPROM for Automotive Applications DS2431-A1 BUS MASTER Tx RESET PULSE FROM MEMORY FUNCTIONS FLOW CHART (FIGURE 7) BUS MASTER Tx ROM FUNCTION COMMAND 33h READ ROM COMMAND? DS2431-A1 Tx PRESENCE PULSE N 55h MATCH ROM COMMAND? F0h SEARCH ROM COMMAND? N N CCh SKIP ROM COMMAND? Y Y Y Y RC = 0 RC = 0 RC = 0 RC = 0 N A5h RESUME COMMAND? Y RC = 1? DS2431-A1 Tx FAMILY CODE (1 BYTE) N DS2431-A1 Tx BIT 0 MASTER Tx BIT 0 DS2431-A1 Tx BIT 0 Y MASTER Tx BIT 0 BIT 0 MATCH? N
PAGE 14
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications Resume [A5h] To maximize the data throughput in a multidrop environment, the Resume function is available. This function checks the status of the RC bit and, if it is set, directly transfers control to the Memory functions, similar to a Skip ROM command. The only way to set the RC bit is through successfully executing the Match ROM or Search ROM command.
PAGE 15
1024-Bit, 1-Wire EEPROM for Automotive Applications DS2431-A1 MASTER Tx "RESET PULSE" MASTER Rx "PRESENCE PULSE" ε tMSP VPUP VIHMASTER VTH VTL VILMAX 0V tRSTL tPDH tF tPDL tREC tRSTH RESISTOR MASTER DS2431-A1 Figure 10. Initialization Procedure: Reset and Presence Pulse Slave-to-Master A read-data time slot begins like a write-one time slot. The voltage on the data line must remain below VTL until the read low time tRL is expired.
PAGE 16
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications WRITE-ONE TIME SLOT tW1L VPUP VIHMASTER VTH VTL VILMAX 0V ε tF tSLOT RESISTOR MASTER WRITE-ZERO TIME SLOT tW0L VPUP VIHMASTER VTH VTL VILMAX 0V ε tF tREC tSLOT RESISTOR MASTER READ-DATA TIME SLOT tMSR tRL VPUP VIHMASTER VTH MASTER SAMPLING WINDOW VTL VILMAX 0V δ tF tREC tSLOT RESISTOR MASTER DS2431-A1 Figure 11.
PAGE 17
1024-Bit, 1-Wire EEPROM for Automotive Applications In a 1-Wire environment, line termination is possible only during transients controlled by the bus master (1-Wire driver). 1-Wire networks, therefore, are susceptible to noise of various origins. Depending on the physical size and topology of the network, reflections from end points and branch points can add up or cancel each other to some extent. Such reflections are visible as glitches or ringing on the 1-Wire communication line.
PAGE 18
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications POLYNOMIAL = X16 + X15 + X2 + 1 1ST STAGE 3RD STAGE 2ND STAGE X0 X2 X1 9TH STAGE X8 4TH STAGE 10TH STAGE X9 11TH STAGE X10 X3 12TH STAGE X11 5TH STAGE 6TH STAGE X4 13TH STAGE X12 X5 14TH STAGE X13 7TH STAGE X6 8TH STAGE X7 15TH STAGE X14 16TH STAGE X15 X16 CRC OUTPUT INPUT DATA Figure 13.
PAGE 19
1024-Bit, 1-Wire EEPROM for Automotive Applications Master to Slave Slave to Master Programming 1-Wire Communication Examples Write Scratchpad RST PD Select WS TA <8–T2:T0 bytes> CRC-16 FF Loop Read Scratchpad RST PD Select RS TA-E/S <8–T2:T0 bytes> CRC-16 FF Loop Copy Scratchpad (Success) RST PD Select CPS TA-E/S Programming AA Loop Copy Scratchpad (Invalid Address or PF = 1 or Copy Protected) RST PD Select CPS TA-E/S FF Loop Read Memory (Success) RST PD Select RM TA FF Loop Read Me
PAGE 20
DS2431-A1 1024-Bit, 1-Wire EEPROM for Automotive Applications Memory Function Example Write to the first 8 bytes of memory page 1. Read the entire memory.
PAGE 21
1024-Bit, 1-Wire EEPROM for Automotive Applications REVISION NUMBER REVISION DATE 0 11/07 1 3/08 DESCRIPTION Initial release. PAGES CHANGED — Removed all references to overdrive speed. 1–5, 8, 11, 13, 14, 15, 18 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.