NM25C040 4K-Bit Serial CMOS EEPROM (Serial Peripheral Interface (SPI) Synchronous Bus) General Description Features The NM25C040 is a 4096-bit CMOS EEPROM with an SPI compatible serial interface. The NM25C040 is designed for data storage in applications requiring both non-volatile memory and insystem data updates. This EEPROM is well suited for applications using the 68HC11 series of microcontrollers that support the SPI interface for high speed communication with peripheral devices via a serial bus to reduce pin count. The NM25C040 is implemented in Fairchild Semiconductor’s floating gate CMOS process that provides superior endurance and data retention. ■ 2.1 MHz clock rate @ 2.7V to 5.5V The serial data transmission of this device requires four signal lines to control the device operation: Chip Select (CS), Clock (SCK), Data In (SI), and Serial Data Out (SO). All programming cycles are completely self-timed and do not require an erase before WRITE. ■ Write Protect (WP) pin and write disable instruction for both hardware and software write protection BLOCK WRITE protection is provided by programming the STATUS REGISTER with one of four levels of write protection. Additionally, separate WRITE enable and WRITE disable instructions are provided for data protection. ■ Data retention greater than 40 years ■ 4096 bits organized as 512 x 8 ■ Multiple chips on the same 3-wire bus with separate chip select lines ■ Self-timed programming cycle ■ Simultaneous programming of 1 to 4 bytes at a time ■ Status register can be polled during programming to monitor READY/BUSY ■ Block write protect feature to protect against accidental writes ■ Endurance: 1,000,000 data changes ■ Packages available: 8-pin DIP, 8-pin SO, or 8-pin TSSOP Hardware data protection is provided by the WP pin to protect against inadvertent programming. The HOLD pin allows the serial communication to be suspended without resetting the serial sequence. Block Diagram CS HOLD SCK SI Instruction Register Program Enable Address Counter/ Register VPP Decoder 1 of 512 VCC VSS Instruction Decoder Control Logic and Clock Generators WP High Voltage Generator and Program Timer EEPROM Array 4096 Bits (512 x 8) Read/Write Amps Data In/Out Register 8 Bits Data Out Buffer SO Non-Volatile Status Register DS012401-1 © 1999 Fairchild Semiconductor Corporation NM25C040 Rev. D.1 1 www.fairchildsemi.com NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) March 1999 NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) Connection Diagram Dual-In-Line Package (N), SO Package (M8), and TSSOP Package (MT8) CS 1 8 VCC SO 2 7 HOLD WP 3 6 SCK VSS 4 5 SI NM25C040 DS012401-2 Top View See Package Number N08E (N), M08A (M8), and MTC08 (MT8) Pin Names CS Chip Select Input SO Serial Data Output WP Write Protect VSS Ground SI Serial Data Input SCK Serial Clock Input HOLD Suspends Serial Data Power Supply VCC Ordering Information NM 25 C XX LZ E XX Letter Description N M8 MT8 8-pin DIP 8-pin SO 8-pin TSSOP Temp. Range None V E 0 to 70°C -40 to +125°C -40 to +85°C Voltage Operating Range Blank L LZ 4.5V to 5.5V 2.7V to 4.5V 2.7V to 4.5V and <1µA Standby Current 040 4K, mode 0 C W CMOS technology Total Array write protect Package Density/Mode Interface 2 NM25C040 Rev. D.1 25 SPI NM Fairchild Nonvolatile Memory Prefix www.fairchildsemi.com Ambient Storage Temperature Ambient Operating Temperature NM25C040 NM25C040E NM25C040V -65°C to +150°C All Input or Output Voltage with Respect to Ground +6.5V to -0.3V Lead Temp. (Soldering, 10 sec.) +300°C ESD Rating 0°C to +70°C -40°C to +85°C -40°C to +125°C Power Supply (VCC) 4.5V to 5.5V 2000V DC and AC Electrical Characteristics 4.5V ≤ VCC ≤ 5.5V (unless otherwise specified) Symbol ICC ICCSB Parameter Conditions Operating Current Min CS = VIL Standby Current CS = VCC IIL Input Leakage VIN = 0 to VCC VOUT = GND to VCC -1 Max Units 3 mA 50 µA +1 µA µA IOL Output Leakage -1 +1 VIL CMOS Input Low Voltage -0.3 VCC * 0.3 V VIH CMOS Input High Voltage 0.7 * VCC VCC + 0.3 V VOL Output Low Voltage IOL = 1.6 mA VOH Output High Voltage IOH = -0.8 mA 0.4 fOP SCK Frequency 2.1 MHz tRI Input Rise Time 2.0 µs tFI Input Fall Time 2.0 µs VCC - 0.8 V V tCLH Clock High Time (Note 2) 190 ns ns tCLL Clock Low Time (Note 2) 190 tCSH Min CS High Time (Note 3) 240 ns tCSS CS Setup Time 240 ns tDIS Data Setup Time 100 ns tHDS HOLD Setup Time 90 ns tCSN CS Hold Time 240 ns ns tDIN Data Hold Time 100 tHDN HOLD Hold Time 90 tPD Output Delay tDH Output Hold Time tLZ HOLD to Output Low Z tDF Output Disable Time tHZ HOLD to Output High Z tWP Write Cycle Time CL = 200 pF ns 240 ns 100 ns 240 ns 0 CL = 200 pF 1–4 Bytes Capacitance TA = 25°C, f = 2.1/1 MHz (Note 4) ns 100 ns 10 ms AC Test Conditions Output Load Test COUT Output Capacitance 3 8 pF Input Pulse Levels 0.1 * VCC – 0.9 * VCC Input Capacitance 2 6 pF Timing Measurement Reference Level 0.3 * VCC - .07 * VCC CIN Typ Max Units CL = 200 pF Symbol Note 1: Stress above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only, and functional operation of the device at these or any other conditions above those indicated in the operational sections of the specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 2: The fOP frequency specification specifies a minimum clock period of 1/fOP. Therefore, for every fOP clock cycle, tCLH + tCLL must be equal to or greater than 1/fOP. For example, if the 2.1MHz period = 476ns and tCLH = 190ns, tCLL must be 286ns. Note 3: CS must be brought high for a minimum of tCSH between consecutive instruction cycles. Note 4: This parameter is periodically sampled and not 100% tested. 3 NM25C040 Rev. D.1 www.fairchildsemi.com NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) Standard Voltage 4.5 ≤ VCC ≤ 5.5V Specifications Operating Conditions Absolute Maximum Ratings (Note 1) Ambient Storage Temperature -65°C to +150°C All Input or Output Voltage with Respect to Ground Ambient Operating Temperature NM25C040L/LZ NM25C040LE/LZE NM25C040LV +6.5V to -0.3V Lead Temp. (Soldering, 10 sec.) +300°C ESD Rating 0°C to +70°C -40°C to +85°C -40°C to +125°C Power Supply (VCC) 2000V 2.7V–4.5V DC and AC Electrical Characteristics 2.7V ≤ VCC ≤ 4.5V (unless otherwise specified) 25C040L/LE 25C040LZ/ZE Symbol Parameter Part Conditions Min. 25C040LV Max. Max Units 3 10 N/A mA µA µA -1 1 µA -1 1 µA VCC * 0.3 -0.3 VCC * 0.3 V VCC + 0.3 VCC * 0.7 VCC + 0.3 V CS = VIL CS = VCC Min ICC ICCSB Operating Current Standby Current IIL Input Leakage VIN = 0 to VCC -1 1 IOL Output Leakage VOUT = GND to VCC -1 1 VIL Input Low Voltage -0.3 VIH Input High Voltage VCC * 0.7 VOL Output Low Voltage IOL = 0.8 mA VOH Output High Voltage IOH = –0.8 mA fOP SCK Frequency 1.0 1.0 MHz tRI Input Rise Time 2.0 2.0 µs tFI Input Fall Time 2.0 µs tCLH Clock High Time (Note 6) 410 410 ns tCLL Clock Low Time (Note 6) 410 410 ns tCSH Min. CS High Time (Note 7) 500 500 ns tCSS CS Setup Time 500 500 ns tDIS Data Setup Time 100 100 ns tHDS HOLD Setup Time 240 240 ns tCSN CS Hold Time 500 500 ns tDIN Data Hold Time 100 100 ns tHDN HOLD Hold Time 240 240 tPD Output Delay tDH Output Hold Time tLZ HOLD Output Low Z tDF Output Disable Time tHZ HOLD to Output Hi Z tWP Write Cycle Time L LZ 3 10 1 0.4 VCC - 0.8 2.0 CL = 200 pF 500 CL = 200 pF 1-4 Bytes Symbol Test COUT Output Capacitance 3 8 pF Input Capacitance 2 6 pF V V ns 500 ns 240 240 ns 500 500 ns 240 240 ns 15 15 ms 0 Capacitance TA = 25°C, f = 2.1/1 MHz (Note 8) CIN VCC - 0.8 0.4 0 ns AC Test Conditions Output Load Typ Max Units CL = 200pF Input Pulse Levels 0.1 * VCC - 0.9 * VCC Timing Measurement Reference Level 0.3 * VCC - 0.7 * VCC Note 5: Stress above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only, and functional operation of the device at these or any other conditions above those indicated in the operational sections of the specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 6: The fOP frequency specification specifies a minimum clock period of 1/fOP. Therefore, for every fOP clock cycle, tCLH + tCLL must be equal to or greater than 1/fOP. For example, if the 2.1MHz period = 476ns and tCLH = 190ns, tCLL must be 286ns. Note 7: CS must be brought high for a minimum of tCSH between consecutive instruction cycles. Note 8: This parameter is periodically sampled and not 100% tested. 4 NM25C040 Rev. D.1 www.fairchildsemi.com NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) Low Voltage 2.7V ≤ VCC ≤ 4.5V Specifications Operating Conditions Absolute Maximum Ratings (Note 5) FIGURE 1. Synchronous Data Timing Diagram tCSH VIH CS VIL VIH SCK tCSS tCLH tCSN tCLL VIL tDIS tDIN VIH SI VIL tPD tDF tDH VOH SO VOL DS012401-3 FIGURE 2. HOLD Timing SCK tHDS tHDN tHDS tHDN HOLD tHZ tLZ SO DS012401-6 FIGURE 3. SPI Serial Interface MASTER MCU NM25C040 DATA OUT (MOSI) SI SO SCK CS DATA IN (MISO) SERIAL CLOCK (CLK) SPI CHIP SELECTION SS0 SS1 SI SO SCK CS SS2 SS3 SI SO SCK CS SI SO SCK CS DS012401-4 5 NM25C040 Rev. D.1 www.fairchildsemi.com NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) ,, , AC Test Conditions (Continued) HOLD: The HOLD pin is used in conjunction with the CS to select the device. Once the device is selected and a serial sequence is underway, HOLD may be forced low to suspend further serial communication with the device without resetting the serial sequence. Note that HOLD must be brought low while the SCK pin is low. The device must remain selected during this sequence. To resume serial communication HOLD is brought high while the SCK pin is low. The SO pin is at a high impedance state during HOLD. TABLE 1. Instruction Set Instruction Instruction Name Opcode Operation WREN 00000110 Set Write Enable Latch WRDI 00000100 Reset Write Enable Latch RDSR 00000101 Read Status Register WRSR 00000001 Write Status Register READ 0000A011 Read Data from Memory Array WRITE 0000A010 Write Data to Memory Array Note: As the NM25C040 requires 9 address bits (4,096 ÷ 8 = 512 bytes = 29), the 9th bit (for R/W instructions) is inputted in the Instruction Set Byte in bit I3. This convention only applies to 4K SPI protocol. MASTER: The device that generates the serial clock is designated as the master. The NM25C040 can never function as a master. SLAVE: The NM25C040 always operates as a slave as the serial clock pin is always an input. TRANSMITTER/RECEIVER: The NM25C040 has separate pins for data transmission (SO) and reception (SI). MSB: The Most Significant Bit is the first bit transmitted and received. CHIP SELECT: The chip is selected when pin CS is low. When the chip is not selected, data will not be accepted from pin SI, and the output pin SO is in high impedance. INVALID OP-CODE: After an invalid code is received, no data is shifted into the NM25C040, and the SO data output pin remains high impedance until a new CS falling edge reinitializes the serial communication. See Figure 5. FIGURE 5. Invalid Op-Code CS SI INVALID CODE SO DS012401-7 SERIAL OP-CODE: The first byte transmitted after the chip is selected with CS going low contains the op-code that defines the operation to be performed. PROTOCOL: When connected to the SPI port of a 68HC11 microcontroller, the NM25C040 accepts a clock phase of 0 and a clock polarity of 0. The SPI protocol for this device defines the byte transmitted on the SI and SO data lines for proper chip operation. See Figure 4. FIGURE 4. SPI Protocol CS … SCK SI Bit 7 Bit 6 … Bit 0 SO Bit 7 … Bit 1 Bit 0 DS012401-5 Data is clocked in on the positive SCK edge and out on the negative SCK edge. 6 NM25C040 Rev. D.1 NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) Functional Description www.fairchildsemi.com TABLE 3. Block Write Protection Levels Level READ SEQUENCE: Reading the memory via the serial SPI link requires the following sequence. The CS line is pulled low to select the device. The READ op-code (which includes A8) is transmitted on the SI line followed by the byte address (A7–A0) to be read. After this is done, data on the SI line becomes don’t care. The data (D7–D0) at the address specified is then shifted out on the SO line. If only one byte is to be read, the CS line can be pulled back to the high level. It is possible to continue the READ sequence as the byte adress is automatically incremented and data will continue to be shifted out. When the highest address is reached (1FF), the address counter rolls over to lowest address (000) allowing the entire memory to be read in one continuous READ cycle. See Figure 6. Status Register Bits BP1 BP0 Array Address Protected 0 0 0 None 1 0 1 180-1FF 2 1 0 100-1FF 3 1 1 000-1FF WRITE ENABLE (WREN): When VCC is applied to the chip, it “powers up” in the write disable state. Therefore, all programming modes must be preceded by a WRITE ENABLE (WREN) instruction. At the completion of a WRITE or WRSR cycle the device is automatically returned to the write disable state. Note that a WRITE DISABLE (WRDI) instruction will also return the device to the write disable state. See Figure 8. NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) Functional Description (Continued) FIGURE 6. Read Sequence CS FIGURE 8. Write Enable SI Read Op-Code Byte Addr. CS Data n SO Data n+1 Data n+2 SI Data n+3 WREN Op-Code DS012401-8 READ STATUS REGISTER (RDSR) : The Read Status Register (RDSR) instruction provides access to the status register is used to interrogate the READY/BUSY and WRITE ENABLE status of the chip. Two non-volatile status register bits are used to select one of four levels of BLOCK WRITE PROTECTION. The status register format is shown in Table 2. SO DS012401-10 WRITE DISABLE (WRDI): To protect against accidental data disturbance the WRITE DISABLE (WRDI) instruction disables all programming modes. See Figure 9. FIGURE 9. Write Disable TABLE 2. Status Register Format Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 X X X X BP1 BP0 WEN RDY CS SI WRDI Op-Code X = Don't Care. Status register Bit 0 = 0 (RDY) indicates that the device is READY; Bit 0 = 1 indicates that a program cycle is in progress. Bit 1 = 0 (WEN) indicates that the device is not WRITE ENABLED; Bit 1 = 1 indicates that the device is WRITE ENABLED. Non-volatile status register Bits 2 and 3 (BP0 and BP1) indicate the level of BLOCK WRITE PROTECTION selected. The block write protection levels and corresponding status register control bits are shown in Table 3. Note that if a RDSR instruction is executed during a programming cycle only the RDY bit is valid. All other bits are 1s. See Figure 7. SO DS012401-11 WRITE SEQUENCE: To program the device, the WRITE PROTECT (WP) pin must be held high and two separate instructions must be executed. The chip must first be write enabled via the WRITE ENABLE instruction and then a WRITE instruction must be executed. Moreover, the address of the memory location(s) to be programmed must be outside the protected address field selected by the Block Write Protection Level. See Table 3. FIGURE 7. Read Status A WRITE command requires the following sequence. The CS line is pulled low to select the device, then the WRITE op-code (which includes A8) is transmitted on the SI line followed by the high order address byte (A10-A8) and the byte address(A7–A0) and the corresponding data (D7-D0) to be written. Programming will start after the CS pin is forced back to a high level. Note that the LOW to HIGH transition of the CS pin must occur during the SCK low time immediately after clocking in the D0 data bit. See Figure 10. CS SI SO RDSR Op-Code SR Data MSB…LSB DS012401-9 7 NM25C040 Rev. D.1 www.fairchildsemi.com The WRSR command requires the following sequence. The CS line is pulled low to select the device and then the WRSR op-code is transmitted on the SI line followed by the data to be programmed. See Figure 12. FIGURE 10. Write Sequence NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) Functional Description (Continued) CS FIGURE 12. Write Status Register SCK CS D2 SI D1 D0 WRSR Op-Code SI SO SR Data xxxxBP1BP0xx DS012401-12 SO The READY/BUSY status of the device can be determined by executing a READ STATUS REGISTER (RDSR) instruction. Bit 0 = 1 indicates that the WRITE cycle is still in progress and Bit 0 = 0 indicates that the WRITE cycle has ended. During the WRITE programming cycle (Bit 0 = 1) only the READ STATUS REGISTER instruction is enabled. DS012401-14 Note that the first four bits are don’t care bits followed by BP1 and BP0 then two additional don’t care bits. Programming will start after the CS pin is forced back to a high level. As in the WRITE instruction the LOW to HIGH transition of the CS pin must occur during the SCK low time immediately after clocking in the last don’t care bit. See Figure 13. The NM25C040 is capable of a 4 byte PAGE WRITE operation. After receipt of each byte of data the two low order address bits are internally incremented by one. The seven high order bits of the address will remain constant. If the master should transmit more than 4 bytes of data, the address counter will “roll over,” and the previously loaded data will be reloaded. See Figure 11. FIGURE 13. Start WRSR Condition CS FIGURE 11. 4 Byte Page Write SCK CS SI SI Write Op-Code Byte Addr (n) Data (n) Data (n + 1) Data (n + 2) BP0 Data (n + 3) SO DS012401-15 The READY/BUSY status of the device can be determined by executing a READ STATUS REGISTER (RDSR) instruction. Bit 0 = 1 indicates that the WRSR cycle is still in progress and Bit 0 = 0 indicates that the WRSR cycle has ended. SO DS012401-13 At the completion of a WRITE cycle the device is automatically returned to the write disable state. At the completion of a WRITE cycle the device is automatically returned to the write disable state. If the device is not WRITE enabled, the device will ignore the WRITE instruction and return to the standby state when CS is forced high. A new CS falling edge is required to re-initialize the serial communication. WRITE STATUS REGISTER (WRSR): The WRITE STATUS REGISTER (WRSR) instruction is used to program the nonvolatile status register Bits 2 and 3 (BP0 and BP1). The WRITE PROTECT (WP) pin must be held high and two separate instructions must be executed. The chip must first be write enabled via the WRITE ENABLE instruction and then a WRSR instruction must be executed. 8 NM25C040 Rev. D.1 www.fairchildsemi.com 0.189 - 0.197 (4.800 - 5.004) 8 7 6 5 0.228 - 0.244 (5.791 - 6.198) 0.010 Max. (0.254) 1 2 3 4 Lead #1 IDENT 0.010 - 0.020 x 45° (0.254 - 0.508) 0.008 - 0.010 (0.203 - 0.254) Typ. all leads 0.150 - 0.157 (3.810 - 3.988) 30° Typ. 0.053 - 0.069 (1.346 - 1.753) 8° Max, Typ. All leads 0.004 - 0.010 (0.102 - 0.254) Seating Plane 0.04 (0.102) All lead tips 0.014 (0.356) 0.016 - 0.050 (0.406 - 1.270) Typ. All Leads 0.050 (1.270) Typ 0.014 - 0.020 Typ. (0.356 - 0.508) 0.008 Typ (0.203) Molded Small Out-Line Package (M8) Package Number M08A 0.373 - 0.400 (9.474 - 10.16) 0.090 (2.286) 8 0.092 DIA (2.337) 7 6 0.250 - 0.005 (6.35 ± 0.127) + Pin #1 IDENT 0.032 ± 0.005 (0.813 ± 0.127) RAD 5 1 1 0.300 - 0.320 (7.62 - 8.128) 7 Pin #1 IDENT Option 1 0.280 MIN (7.112) 8 2 3 0.040 Typ. (1.016) 0.030 MAX (0.762) 20° ± 1° 4 Option 2 0.145 - 0.200 (3.683 - 5.080) 0.039 (0.991) 0.130 ± 0.005 (3.302 ± 0.127) 95° ± 5° 0.009 - 0.015 (0.229 - 0.381) +0.040 0.325 -0.015 +1.016 8.255 -0.381 0.125 (3.175) DIA NOM 0.125 - 0.140 (3.175 - 3.556) 0.065 (1.651) 90° ± 4° Typ 0.018 ± 0.003 (0.457 ± 0.076) 0.100 ± 0.010 (2.540 ± 0.254) 0.045 ± 0.015 (1.143 ± 0.381) 0.020 (0.508) Min 0.060 (1.524) 0.050 (1.270) Molded Dual-In-Line Package (N) Package Number N08E 9 NM25C040 Rev. D.1 www.fairchildsemi.com NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) Physical Dimensions inches (millimeters) unless otherwise noted 0.114 - 0.122 (2.90 - 3.10) 8 5 (4.16) Typ (7.72) Typ 0.246 - 0.256 0.169 - 0.177 (6.25 - 6.50) (4.30 - 4.50) (1.78) Typ (0.42) Typ 0.123 - 0.128 (0.65) Typ (3.13 - 3.30) 1 Land pattern recommendation 4 Pin #1 IDENT 0.0433 Max (1.1) 0.002 - 0.006 (0.05 - 0.15) 0.0256 (0.65) Typ. 0.0035 - 0.0079 See detail A 0.0075 - 0.0098 (0.19 - 0.30) Gage plane 0°-8° Note: Metal mask option for 16-byte page size. DETAIL A Typ. Scale: 40X 0.020 - 0.028 [0.50 - 0.70] Seating plane 0.0075 - 0.0098 [0.19 - 0.25] 8-Pin Molded TSSOP, JEDEC (MT8) Package Number MTC08 Life Support Policy Fairchild's products are not authorized for use as critical components in life support devices or systems without the express written approval of the President of Fairchild Semiconductor Corporation. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. Fairchild Semiconductor Americas Customer Response Center Tel. 1-888-522-5372 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. Fairchild Semiconductor Europe Fax: +44 (0) 1793-856858 Deutsch Tel: +49 (0) 8141-6102-0 English Tel: +44 (0) 1793-856856 Français Tel: +33 (0) 1-6930-3696 Italiano Tel: +39 (0) 2-249111-1 Fairchild Semiconductor Hong Kong 8/F, Room 808, Empire Centre 68 Mody Road, Tsimshatsui East Kowloon. Hong Kong Tel; +852-2722-8338 Fax: +852-2722-8383 10 NM25C040 Rev. D.1 Fairchild Semiconductor Japan Ltd. 4F, Natsume Bldg. 2-18-6, Yushima, Bunkyo-ku Tokyo, 113-0034 Japan Tel: 81-3-3818-8840 Fax: 81-3-3818-8841 www.fairchildsemi.com NM25C040 4K-Bit Serial CMOS EEPROM (Serial Periphrial Interface (SPI) Synchronous Bus) Physical Dimensions inches (millimeters) unless otherwise noted