Datasheet

ManualsBrandsSTMICROELECTRONICS ManualsIntegrated Circuits (ICs)SOIC 8 256 kBit 32 K x 8

This is information on a product in full production.

December 2012 Doc ID 6757 Rev 30 1/40

M24256-BW M24256-BR M24256-BF

M24256-DR M24256-DF

256-Kbit serial I²C bus EEPROM

Datasheet − production data

Features

■ Compatible with all I

C bus modes:

–1 MHz

– 400 kHz

– 100 kHz

■ Memory array:

– 256 Kbit (32 Kbytes) of EEPROM

– Page size: 64 bytes

– Additional Write lockable page

(M24256-D order codes)

■ Single supply voltage and high speed:

– 1 MHz clock from 1.7 V to 5.5 V

■ Write:

– Byte Write within 5 ms

– Page Write within 5 ms

■ Operating temperature range: from -40 °C up

to +85 °C

■ Random and sequential Read modes

■ Write protect of the whole memory array

■ Enhanced ESD/Latch-Up protection

■ More than 4 million Write cycles

■ More than 200-year data retention

■ Packages:

– RoHS compliant and halogen-free

(ECOPACK

)

SO8 (MN)

150 mil width

TSSOP8 (DW)

169 mil width

UFDFPN8

(MC)

WLCSP (CS)

www.st.com

Summary of content (40 pages)

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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 256-Kbit serial I²C bus EEPROM Datasheet − production data Features ■ Compatible with all I2C bus modes: – 1 MHz – 400 kHz – 100 kHz ■ Memory array: – 256 Kbit (32 Kbytes) of EEPROM – Page size: 64 bytes – Additional Write lockable page (M24256-D order codes) ■ Single supply voltage and high speed: – 1 MHz clock from 1.7 V to 5.
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Contents M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Signal description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1 Serial Clock (SCL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 Serial Data (SDA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Contents 5.2.2 Current Address Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.2.3 Sequential Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.3 Read Identification Page (M24256-D only) . . . . . . . . . . . . . . . . . . . . . . . 20 5.4 Read the lock status (M24256-D only) . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6 Initial delivery state . . . . .
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List of tables M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Table 19. Table 20. Table 21. Table 22. Table 23. 4/40 Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Device select code . . . . . . . . . . . . . . . . . . . . . . . .
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF List of figures List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8-pin package connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Description 1 M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Description The M24256 is a 256-Kbit I2C-compatible EEPROM (Electrically Erasable PROgrammable Memory) organized as 32 K × 8 bits. The M24256-BW can operate with a supply voltage from 2.5 V to 5.5 V, the M24256-BR and M24256-DR can operate with a supply voltage from 1.8 V to 5.5 V, and the M24256-BF and M24256-DF can operate with a supply voltage from 1.7 V to 5.5 V.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Figure 2. Description 8-pin package connections % % % 633 6## 7# 3#, 3$! !) F 1. DU: Don't Use (if connected, must be connected to VSS) 2. See Section 9: Package mechanical data for package dimensions, and how to identify pin 1. Figure 3.
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Signal description M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 2 Signal description 2.1 Serial Clock (SCL) The signal applied on the SCL input is used to strobe the data available on SDA(in) and to output the data on SDA(out). 2.2 Serial Data (SDA) SDA is an input/output used to transfer data in or data out of the device. SDA(out) is an open drain output that may be wire-OR’ed with other open drain or open collector signals on the bus.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 2.6 Supply voltage (VCC) 2.6.1 Operating supply voltage VCC Signal description Prior to selecting the memory and issuing instructions to it, a valid and stable VCC voltage within the specified [VCC(min), VCC(max)] range must be applied (see Operating conditions in Section 8: DC and AC parameters).
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Memory organization 3 M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Memory organization The memory is organized as shown below. Figure 5.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 4 Device operation Device operation The device supports the I2C protocol. This is summarized in Figure 6. Any device that sends data on to the bus is defined to be a transmitter, and any device that reads the data to be a receiver. The device that controls the data transfer is known as the bus master, and the other as the slave device. A data transfer can only be initiated by the bus master, which will also provide the serial clock for synchronization.
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Device operation 4.1 M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Start condition Start is identified by a falling edge of Serial Data (SDA) while Serial Clock (SCL) is stable in the high state. A Start condition must precede any data transfer instruction. The device continuously monitors (except during a Write cycle) Serial Data (SDA) and Serial Clock (SCL) for a Start condition. 4.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 4.5 Device operation Device addressing To start communication between the bus master and the slave device, the bus master must initiate a Start condition. Following this, the bus master sends the device select code, shown in Table 2 (on Serial Data (SDA), most significant bit first). Table 2.
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Instructions M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 5 Instructions 5.1 Write operations Following a Start condition the bus master sends a device select code with the R/W bit (RW) reset to 0. The device acknowledges this, as shown in Figure 7, and waits for two address bytes. The device responds to each address byte with an acknowledge bit, and then waits for the data byte. Table 3. A15 Table 4.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Byte Write After the device select code and the address bytes, the bus master sends one data byte. If the addressed location is Write-protected, by Write Control (WC) being driven high, the device replies with NoAck, and the location is not modified. If, instead, the addressed location is not Write-protected, the device replies with Ack. The bus master terminates the transfer by generating a Stop condition, as shown in Figure 7. Figure 7.
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Instructions 5.1.2 M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Page Write The Page Write mode allows up to 64 bytes to be written in a single Write cycle, provided that they are all located in the same page in the memory: that is, the most significant memory address bits, A15/A6, are the same. If more bytes are sent than will fit up to the end of the page, a “roll-over” occurs, i.e. the bytes exceeding the page end are written on the same page, from location 0.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 5.1.3 Instructions Write Identification Page (M24256-D only) The Identification Page (64 bytes) is an additional page which can be written and (later) permanently locked in Read-only mode. It is written by issuing the Write Identification Page instruction.
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Instructions 5.1.6 M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Minimizing Write delays by polling on ACK The maximum Write time (tw) is shown in AC characteristics tables in Section 8: DC and AC parameters, but the typical time is shorter. To make use of this, a polling sequence can be used by the bus master. The sequence, as shown in Figure 9, is: ● Initial condition: a Write cycle is in progress.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Read operations Read operations are performed independently of the state of the Write Control (WC) signal. After the successful completion of a Read operation, the device internal address counter is incremented by one, to point to the next byte address. For the Read instructions, after each byte read (data out), the device waits for an acknowledgment (data in) during the 9th bit time.
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Instructions 5.2.1 M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Random Address Read A dummy Write is first performed to load the address into this address counter (as shown in Figure 10) but without sending a Stop condition. Then, the bus master sends another Start condition, and repeats the device select code, with the RW bit set to 1. The device acknowledges this, and outputs the contents of the addressed byte.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 5.4 Initial delivery state Read the lock status (M24256-D only) The locked/unlocked status of the Identification page can be checked by transmitting a specific truncated command [Identification Page Write instruction + one data byte] to the device. The device returns an acknowledge bit if the Identification page is unlocked, otherwise a NoAck bit if the Identification page is locked.
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Maximum rating 7 M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Maximum rating Stressing the device outside the ratings listed in Table 5 may cause permanent damage to the device. These are stress ratings only, and operation of the device at these, or any other conditions outside those indicated in the operating sections of this specification, is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 5.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 8 DC and AC parameters DC and AC parameters This section summarizes the operating and measurement conditions, and the DC and AC characteristics of the device. Table 6. Operating conditions (voltage range W) Symbol Min. Max. Unit Supply voltage 2.5 5.5 V TA Ambient operating temperature –40 85 °C fC Operating clock frequency - 1 MHz Min. Max. Unit Supply voltage 1.8 5.
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DC and AC parameters Table 10. M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Input parameters Parameter(1) Symbol Test condition Min. Max. Unit CIN Input capacitance (SDA) - - 8 pF CIN Input capacitance (other pins) - - 6 pF VIN < 0.3 VCC 30 - kΩ VIN > 0.7 VCC 500 - kΩ ZL ZH Input impedance (E2, E1, E0, WC)(2) 1. Characterized only, not tested in production. 2. E2, E1, E0 input impedance when the memory is selected (after a Start condition). Table 11.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Table 13. DC characteristics (M24256-BW, device grade 6) Symbol Parameter ILI Input leakage current (SCL, SDA, E2, E1, E0) ILO Output leakage current ICC ICC0 ICC1 VIL VIH VOL DC and AC parameters Test conditions (in addition to those in Table 6) Min. Max. Unit VIN = VSS or VCC, device in Standby mode - ±2 µA SDA in Hi-Z, external voltage applied on SDA: VSS or VCC - ±2 µA VCC = 2.
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DC and AC parameters Table 14. Symbol M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF DC characteristics (M24256-BR, M24256-DR, device grade 6) Test conditions(1) (in addition to those in Table 7) Parameter Min. Max. Unit ILI Input leakage current (E1,E2, SCL, SDA) VIN = VSS or VCC, device in Standby mode - ±2 µA ILO Output leakage current SDA in Hi-Z, external voltage applied on SDA: VSS or VCC - ±2 µA VCC = 1.8 V, fc= 400 kHz - 0.8 mA fc= 1 MHz(2) - 2.5 mA During tW, VCC = 1.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Table 15. Symbol DC and AC parameters DC characteristics (M24256-BF, M24256-DF, device grade 6) Test conditions(1) (in addition to those in Table 8) Parameter Min. Max. Unit ILI Input leakage current (E1, E2, SCL, SDA) VIN = VSS or VCC device in Standby mode - ±2 µA ILO Output leakage current SDA in Hi-Z, external voltage applied on SDA: VSS or VCC - ±2 µA VCC = 1.7 V, fc= 400 kHz - 0.8 mA fc= 1 MHz(2) - 2.5 mA VCC = 1.
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DC and AC parameters Table 16. M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 400 kHz AC characteristics Symbol Alt. fC fSCL Clock frequency tCHCL tHIGH tCLCH tLOW tQL1QL2(1) tF tXH1XH2 tR Parameter Min. Max.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Table 17. 1 MHz AC characteristics Parameter(1) Symbol Alt. fC fSCL Clock frequency tCHCL tHIGH tCLCH tXH1XH2 tXL1XL2 tQL1QL2 (3) DC and AC parameters Min. Max.
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DC and AC parameters M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Figure 12. Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 400 kHz "US LINE PULL UP RESISTOR K K½ 4HE 2 BUS X #BUS TIME CONSTANT MUST BE BELOW THE NS TIME CONSTANT LINE REPRESENTED ON THE LEFT 2 BU S § # BU S (ERE 2BUS § #BUS NS 6## 2BUS N S )£# BUS MASTER 3#, - XXX 3$! P& "US LINE CAPACITOR P& #BUS AI B Figure 13.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF DC and AC parameters Figure 14.
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Package mechanical data 9 M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. Figure 15. TSSOP8 – 8-lead thin shrink small outline, package outline 1. Drawing is not to scale. Table 18.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Package mechanical data Figure 16. SO8N – 8-lead plastic small outline, 150 mils body width, package outline h x 45˚ A2 A c ccc b e 0.25 mm GAUGE PLANE D k 8 E1 E 1 L A1 L1 SO-A 1. Drawing is not to scale. Table 19. SO8N – 8-lead plastic small outline, 150 mils body width, package data inches (1) millimeters Symbol Typ Min A Max Typ Min 1.750 Max 0.0689 A1 0.100 A2 1.250 b 0.280 0.480 0.0110 0.0189 c 0.170 0.230 0.
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Package mechanical data M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Figure 17. UFDFPN8 (MLP8) - 8-lead ultra thin fine pitch dual flat no lead, package outline E $ , , 0IN % B % + , ! $ EEE ! :7?-%E6 1. Drawing is not to scale. 2. The central pad (area E2 by D2 in the above illustration) is internally pulled to VSS. It must not be connected to any other voltage or signal line on the PCB, for example during the soldering process. Table 20.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Package mechanical data Figure 18. M24256-DFCS6TP/K, WLCSP 8-bump wafer-level chip scale package outline BBB : $ 8 ( 9 2EFERENCE E & E AAA ! ! 8 7AFER BACK SIDE E & $ETAIL ! % E ' /RIENTATION "UMPS SIDE 3IDE VIEW "UMP ! EEE : B CCC DDD : 3EATING PLANE - : 89 - : $ETAIL ! 2OTATED #G?-%?6 1.
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Package mechanical data Table 21. M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF M24256-DFCS6TP/K, WLCSP 8-bump wafer-level chip scale package mechanical data inches(1) millimeters Symbol Typ Min Max Typ Min Max A 0.540 0.500 0.580 0.0213 0.0197 0.0228 A1 0.190 0.0075 A2 0.350 0.0138 b 0.270 0.0106 D 1.271 1.291 0.0500 0.0508 E 1.358 1.378 0.0535 0.0543 e 0.800 0.0315 e1 0.693 0.0273 e2 0.400 0.0157 e3 0.400 0.0157 F 0.333 0.0131 G 0.235 0.0093 H 0.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF 10 Part numbering Part numbering Table 22. Ordering information scheme Example: M24256 - D W MN 6 T P /K Device type M24 = I2C serial access EEPROM Device function 256 = 256 Kbit (32 K x 8) Device family B = Without Identification page D = With additional Identification page Operating voltage W = VCC = 2.5 V to 5.5 V R = VCC = 1.8 V to 5.5 V F = VCC = 1.7 V to 5.
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Revision history 11 Revision history Table 23. Document revision history Date Revision 19-Jan-2010 20 Revision number corrected at bottom of pages. 04-Mar-2010 21 Process description corrected in Table 23: Ordering information scheme. 22 Updated text in: Features, Section 1: Description, Section 3.1: Start condition, Section 3.6: Write operations, Section 3.9: Write Identification Page (M24256-D only), Section 3.10: Lock Identification Page (M24256-D only), Section 3.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Table 23. Date Revision history Document revision history (continued) Revision Changes 25 Updated UFDFPN8 silhouette on cover page, Figure 16: UFDFPN8 (MLP8) 8-lead ultra thin fine pitch dual flat package no lead 2 x 3 mm, outline and Table 21: UFDFPN8 (MLP8) 8-lead ultra thin fine pitch dual flat package no lead 2 x 3 mm, mechanical data to add MC version.
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M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale.