25AA040/25LC040/25C040

4K SPI™ Bus Serial EEPROM

Device Selection Table Communication to the device can be paused via the
hold pin (HOLD). While the device is paused, transi-
Part VCC Max. Clock Temp. tions on its inputs will be ignored, with the exception of
Number Range Frequency Ranges Chip Select, allowing the host to service higher priority
interrupts. Also, write operations to the device can be
25AA040 1.8-5.5V 1 MHz I
disabled via the write-protect pin (WP).
25LC040 2.5-5.5V 2 MHz I
Package Types
25C040 4.5-5.5V 3 MHz I,E
PDIP CS 1 8 VCC

25XX040
Features SO 2 7 HOLD

• Low-power CMOS technology WP 3 6 SCK

- Write current: 3 mA typical VSS 4 5 SI
- Read current: 500 µA typical
- Standby current: 500 nA typical SOIC
CS 1 8 VCC
• 512 x 8-bit organization

25XX040
SO 2 7 HOLD
• 16 byte page
WP 3 6 SCK
• Write cycle time: 5 ms max.
• Self-timed ERASE and WRITE cycles VSS 4 5 SI

• Block write protection

TSSOP
- Protect none, 1/4, 1/2 or all of array HOLD 1 8 SCK

25XX040
• Built-in write protection VCC 2 7 SI
- Power on/off data protection circuitry 3 6
CS VSS
- Write enable latch
SO 4 5 WP
- Write-protect pin
• Sequential read
Block Diagram
• High reliability
- Endurance: 1M cycles Status
HV Generator
Register
- Data retention: > 200 years
- ESD protection: > 4000V
• 8-pin PDIP, SOIC, and TSSOP packages
• Temperature ranges supported:
- Industrial (I): -40°C to +85°C Memory EEPROM
- Automotive (E) (25C040): -40°C to +125°C I/O Control Array
Logic Control
Logic XDEC
Description Page
Latches
The Microchip Technology Inc. 25AA040/25LC040/
25C040 (25XX040*) is a 4 Kbit serial Electrically
Erasable PROM. The memory is accessed via a simple SI
Serial Peripheral Interface™ (SPI™) compatible serial SO Y Decoder
bus. The bus signals required are a clock input (SCK) CS
plus separate data in (SI) and data out (SO) lines. SCK
Access to the device is controlled through a Chip Sense Amp.
HOLD
Select (CS) input. R/W Control
WP
*25XX040 is used in this document as a generic part number VCC
for the 25AA040/25LC040/25C040 devices. SPI is a VSS
trademark of Motorola Corporation.

 2003 Microchip Technology Inc. DS21204D-page 1

25AA040/25LC040/25C040
1.0 ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings(†)
VCC .............................................................................................................................................................................7.0V
All inputs and outputs w.r.t. VSS .......................................................................................................... -0.6V to VCC+1.0V
Storage temperature .................................................................................................................................-65°C to 150°C
Ambient temperature under bias ...............................................................................................................-65°C to 125°C
ESD protection on all pins ......................................................................................................................................... 4 KV

† NOTICE: Stresses 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 those or any other conditions above those
indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for an
extended period of time may affect device reliability

TABLE 1-1: DC CHARACTERISTICS

Industrial (I): TA = -40°C to +85°C VCC = 1.8V to 5.5V
DC CHARACTERISTICS
Automotive (E): TA = -40°C to +125°C VCC = 4.5V to 5.5V (25C040 only)
Param.
Sym. Characteristic Min. Max. Units Test Conditions
No.
D001 VIH1 High-level input 2.0 VCC+1 V VCC ≥ 2.7V (Note)
D002 VIH2 voltage 0.7 VCC VCC+1 V VCC< 2.7V (Note)
D003 VIL1 Low-level input -0.3 0.8 V VCC ≥ 2.7V (Note)
D004 VIL2 voltage -0.3 0.3 VCC V VCC < 2.7V (Note)
D005 VOL Low-level output — 0.4 V IOL = 2.1 mA
D006 VOL voltage — 0.2 V IOL = 1.0 mA, VCC < 2.5V
D007 VOH High-level output VCC -0.5 — V IOH =-400 µA
voltage
D008 ILI Input leakage current — ±1 µA CS = VCC, VIN = VSS TO VCC
D009 ILO Output leakage — ±1 µA CS = VCC, VOUT = VSS TO VCC
current
D010 CINT Internal Capacitance — 7 pF TA = 25°C, CLK = 1.0 MHz,
(all inputs and VCC = 5.0V (Note)
outputs)
D011 ICC Read Operating Current — 1 mA VCC = 5.5V; FCLK = 3.0 MHz; SO = Open
— 500 µA VCC = 2.5V; FCLK = 2.0 MHz; SO = Open
D012 ICC Write — 5 mA VCC = 5.5V
— 3 mA VCC = 2.5V
D013 ICCS Standby Current — 5 µA CS = VCC = 5.5V, Inputs tied to VCC or
— 1 µA VSS
CS = VCC = 2.5V, Inputs tied to VCC or
VSS
Note: This parameter is periodically sampled and not 100% tested.

DS21204D-page 2  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
TABLE 1-2: AC CHARACTERISTICS
Industrial (I): TA = -40°C to +85°C VCC = 1.8V to 5.5V
AC CHARACTERISTICS
Automotive (E): TA = -40°C to +125°C VCC = 4.5V to 5.5V (25C040 only)

Param
Sym. Characteristic Min. Max. Units Test Conditions
No.
1 FCLK Clock Frequency — 3 MHz VCC = 4.5V to 5.5V
— 2 MHz VCC = 2.5V to 4.5V
— 1 MHz VCC = 1.8V to 2.5V
2 TCSS CS Setup Time 100 — ns VCC = 4.5V to 5.5V
250 — ns VCC = 2.5V to 4.5V
500 — ns VCC = 1.8V to 2.5V
3 TCSH CS Hold Time 150 — ns VCC = 4.5V to 5.5V
250 — ns VCC = 2.5V to 4.5V
475 — ns VCC = 1.8V to 2.5V
4 TCSD CS Disable Time 500 — ns —
5 TSU Data Setup Time 30 — ns VCC = 4.5V to 5.5V
50 — ns VCC = 2.5V to 4.5V
50 — ns VCC = 1.8V to 2.5V
6 THD Data Hold Time 50 — ns VCC = 4.5V to 5.5V
100 — ns VCC = 2.5V to 4.5V
100 — ns VCC = 1.8V to 2.5V
7 TR CLK Rise Time — 2 µs (Note 1)
8 TF CLK Fall Time — 2 µs (Note 1)
9 THI Clock High Time 150 — ns VCC = 4.5V to 5.5V
230 — ns VCC = 2.5V to 4.5V
475 — ns VCC = 1.8V to 2.5V
10 TLO Clock Low Time 150 — ns VCC = 4.5V to 5.5V
230 — ns VCC = 2.5V to 4.5V
475 — ns VCC = 1.8V to 2.5V
11 TCLD Clock Delay Time 50 — ns —
12 TCLE Clock Enable Time 50 — ns —
13 TV Output Valid from Clock Low — 150 ns VCC = 4.5V to 5.5V
— 230 ns VCC = 2.5V to 4.5V
— 475 ns VCC = 1.8V to 2.5V
14 THO Output Hold Time 0 — ns (Note 1)
15 TDIS Output Disable Time — 200 ns VCC = 4.5V to 5.5V (Note 1)
— 250 ns VCC = 2.5V to 4.5V (Note 1)
— 500 ns VCC = 1.8V to 2.5V (Note 1)
16 THS HOLD Setup Time 100 — ns VCC = 4.5V to 5.5V
100 — ns VCC = 2.5V to 4.5V
200 — ns VCC = 1.8V to 2.5V
17 THH HOLD Hold Time 100 — ns VCC = 4.5V to 5.5V
100 — ns VCC = 2.5V to 4.5V
200 — ns VCC = 1.8V to 2.5V
18 THZ HOLD Low to Output High-Z 100 — ns VCC = 4.5V to 5.5V (Note 1)
150 — ns VCC = 2.5V to 4.5V (Note 1)
200 — ns VCC = 1.8V to 2.5V (Note 1)
19 THV HOLD High to Output Valid 100 — ns VCC = 4.5V to 5.5V
150 — ns VCC = 2.5V to 4.5V
200 — ns VCC = 1.8V to 2.5V
20 TWC Internal Write Cycle Time — 5 ms —
21 — Endurance 1M — E/W (Note 2)
Cycles
Note 1: This parameter is periodically sampled and not 100% tested.
2: This parameter is not tested but ensured by characterization. For endurance estimates in a specific application, please
consult the Total Endurance™ Model which can be obtained from our web site: www.microchip.com.

 2003 Microchip Technology Inc. DS21204D-page 3

25AA040/25LC040/25C040
FIGURE 1-1: HOLD TIMING

CS
17 17
16 16

SCK
18 19
high-impedance
SO n+2 n+1 n n n-1

don’t care 5
SI n+2 n+1 n n n-1

HOLD

FIGURE 1-2: SERIAL INPUT TIMING

CS 12
2 11
7
Mode 1,1 8 3

SCK Mode 0,0

5 6

SI MSB in LSB in

high-impedance
SO

FIGURE 1-3: SERIAL OUTPUT TIMING

CS

9 10 3
Mode 1,1
SCK Mode 0,0
13
15
14

SO MSB out ISB out

don’t care
SI

DS21204D-page 4  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
TABLE 1-3: AC TEST CONDITIONS FIGURE 1-4: AC TEST CIRCUIT AC
AC Waveform: VCC
VLO = 0.2V —
VHI = VCC - 0.2V (Note 1)
2.25 KΩ
VHI = 4.0V (Note 2)
Timing Measurement Reference Level SO
Input 0.5 VCC
1.8 KΩ 100 pF
Output 0.5 VCC
Note 1: For VCC ≤ 4.0V
2: For VCC > 4.0V

 2003 Microchip Technology Inc. DS21204D-page 5

25AA040/25LC040/25C040
2.0 PIN DESCRIPTIONS 2.4 Serial Input (SI)
The descriptions of the pins are listed in Table 2-1. The SI pin is used to transfer data into the device. It
receives instructions, addresses and data. Data is
TABLE 2-1: PIN FUNCTION TABLE latched on the rising edge of the serial clock.

Name PDIP SOIC TSSOP Description 2.5 Serial Clock (SCK)

CS 1 1 3 Chip Select Input The SCK is used to synchronize the communication
SO 2 2 4 Serial Data Output
between a master and the 25XX040. Instructions,
addresses or data present on the SI pin are latched on
WP 3 3 5 Write-Protect Pin the rising edge of the clock input, while data on the SO
VSS 4 4 6 Ground pin is updated after the falling edge of the clock input.
SI 5 5 7 Serial Data Input
2.6 Hold (HOLD)
SCK 6 6 8 Serial Clock Input
HOLD 7 7 1 Hold Input
The HOLD pin is used to suspend transmission to the
25XX040 while in the middle of a serial sequence with-
VCC 8 8 2 Supply Voltage out having to retransmit the entire sequence again at a
later time. It must be held high any time this function is
2.1 Chip Select (CS) not being used. Once the device is selected and a
serial sequence is underway, the HOLD pin may be
A low level on this pin selects the device. A high level pulled low to pause further serial communication with-
deselects the device and forces it into Standby mode. out resetting the serial sequence. The HOLD pin must
However, a programming cycle which is already be brought low while SCK is low, otherwise the HOLD
initiated or in progress will be completed, regardless of function will not be invoked until the next SCK high-to-
the CS input signal. If CS is brought high during a low transition. The 25XX040 must remain selected dur-
program cycle, the device will go in Standby mode as ing this sequence. The SI, SCK and SO pins are in a
soon as the programming cycle is complete. When the high-impedance state during the time the part is
device is deselected, SO goes into the high-impedance paused and transitions on these pins will be ignored. To
state, allowing multiple parts to share the same SPI resume serial communication, HOLD must be brought
bus. A low-to-high transition on CS after a valid write high while the SCK pin is low, otherwise serial
sequence initiates an internal write cycle. After power- communication will not resume. Lowering the HOLD
up, a low level on CS is required prior to any sequence line at any time will tri-state the SO line.
being initiated.

2.2 Serial Output (SO)

The SO pin is used to transfer data out of the 25XX040.
During a read cycle, data is shifted out on this pin after
the falling edge of the serial clock.

2.3 Write-Protect (WP)

This pin is a hardware write-protect input pin. When
WP is low, all writes to the array or Status register are
disabled, but any other operation functions normally.
When WP is high, all functions, including nonvolatile
writes operate normally. WP going low at any time will
reset the write enable latch and inhibit programming,
except when an internal write has already begun. If an
internal write cycle has already begun, WP going low
will have no effect on the write. See Table 3-2 for Write-
Protect Functionality Matrix.

DS21204D-page 6  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
3.0 FUNCTIONAL DESCRIPTION 3.3 Write Sequence
Prior to any attempt to write data to the 25XX040, the
3.1 Principles of Operation write enable latch must be set by issuing the WREN
The 25XX040 is a 512 byte Serial EEPROM designed instruction (Figure 3-4). This is done by setting CS low
to interface directly with the Serial Peripheral Interface and then clocking out the proper instruction into the
(SPI) port of many of today’s popular microcontroller 25XX040. After all eight bits of the instruction are
families, including Microchip’s PIC16C6X/7X micro- transmitted, the CS must be brought high to set the
controllers. It may also interface with microcontrollers write enable latch. If the write operation is initiated
that do not have a built-in SPI port by using discrete immediately after the WREN instruction without CS
I/O lines programmed properly with the software. being brought high, the data will not be written to the
array because the write enable latch will not have been
The 25XX040 contains an 8-bit instruction register. The properly set.
part is accessed via the SI pin, with data being clocked
in on the rising edge of SCK. The CS pin must be low Once the write enable latch is set, the user may
and the HOLD pin must be high for the entire operation. proceed by setting the CS low, issuing a WRITE
The WP pin must be held high to allow writing to the instruction, followed by the address, and then the data
memory array. to be written. Keep in mind that the Most Significant
address bit (A8) is included in the instruction byte. Up
Table 3-1 contains a list of the possible instruction to 16 bytes of data can be sent to the 25XX040 before
bytes and format for device operation. The Most a write cycle is necessary. The only restriction is that all
Significant address bit (A8) is located in the instruction of the bytes must reside in the same page. A page
byte. All instructions, addresses, and data are address begins with XXXX 0000 and ends with XXXX
transferred MSB first, LSB last. 1111. If the internal address counter reaches XXXX
Data is sampled on the first rising edge of SCK after CS 1111 and the clock continues, the counter will roll back
goes low. If the clock line is shared with other periph- to the first address of the page and overwrite any data
eral devices on the SPI bus, the user can assert the in the page that may have been written.
HOLD input and place the 25XX040 in ‘HOLD’ mode. For the data to be actually written to the array, the CS
After releasing the HOLD pin, operation will resume must be brought high after the least significant bit (D0)
from the point when the HOLD was asserted. of the nth data byte has been clocked in. If CS is
brought high at any other time, the write operation will
3.2 Read Sequence not be completed. Refer to Figure 3-2 and Figure 3-3
for more detailed illustrations on the byte write
The part is selected by pulling CS low. The 8-bit read
sequence and the page write sequence respectively.
instruction with the A8 address bit is transmitted to the
While the write is in progress, the Status register may
25XX040 followed by the lower 8-bit address (A7
be read to check the status of the WIP, WEL, BP1 and
through A0). After the correct READ instruction and
BP0 bits (Figure 3-6). A read attempt of a memory
address are sent, the data stored in the memory at the
array location will not be possible during a write cycle.
selected address is shifted out on the SO pin. The data
When the write cycle is completed, the write enable
stored in the memory at the next address can be read
latch is reset.
sequentially by continuing to provide clock pulses. The
internal address pointer is automatically incremented
to the next higher address after each byte of data is
shifted out. When the highest address is reached
(01FFh), the address counter rolls over to address
0000h allowing the read cycle to be continued
indefinitely. The read operation is terminated by raising
the CS pin (Figure 3-1).
TABLE 3-1: INSTRUCTION SET
Instruction Name Instruction Format Description
READ 0000 A8011 Read data from memory array beginning at selected address
WRITE 0000 A8010 Write data to memory array beginning at selected address
WRDI 0000 0100 Reset the write enable latch (disable write operations)
WREN 0000 0110 Set the write enable latch (enable write operations)
RDSR 0000 0101 Read Status register
WRSR 0000 0001 Write Status register
Note: A8 is the 9th address bit necessary to fully address 512 bytes.

 2003 Microchip Technology Inc. DS21204D-page 7

25AA040/25LC040/25C040
FIGURE 3-1: READ SEQUENCE

CS

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
SCK

instruction lower address byte

SI 0 0 0 0 A8 0 1 1 A7 6 5 4 3 2 1 A0 don’t care

data out
high-impedance
SO 7 6 5 4 3 2 1 0

FIGURE 3-2: BYTE WRITE SEQUENCE

CS
TWC

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
SCK

instruction lower address byte data byte

SI 0 0 0 0 A8 0 1 0 A7 6 5 4 3 2 1 A0 7 6 5 4 3 2 1 0

high-impedance
SO

FIGURE 3-3: PAGE WRITE SEQUENCE

CS

0 1 2 3 4 5 6 7 8 9 10 11 13 14 15 16 17 18 19 20 21 22 23 24
SCK

instruction lower address byte data byte 1

SI 0 0 0 0 A8 0 1 0 A7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0

CS

25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
SCK

data byte 2 data byte 3 data byte n (16 max)

SI 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0

DS21204D-page 8  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
3.4 Write Enable (WREN) and Write The following is a list of conditions under which the
Disable (WRDI) write enable latch will be reset:
• Power-up
The 25XX040 contains a write enable latch. See
Table 3-3 for the Write-Protect Functionality Matrix. • WRDI instruction successfully executed
This latch must be set before any write operation will be • WRSR instruction successfully executed
completed internally. The WREN instruction will set the • WRITE instruction successfully executed
latch, and the WRDI will reset the latch. • WP line is low

FIGURE 3-4: WRITE ENABLE SEQUENCE

CS

0 1 2 3 4 5 6 7
SCK

SI 0 0 0 0 0 1 1 0

high-impedance
SO

FIGURE 3-5: WRITE DISABLE SEQUENCE

CS

0 1 2 3 4 5 6 7
SCK

SI 0 0 0 0 0 1 10 0

high-impedance
SO

 2003 Microchip Technology Inc. DS21204D-page 9

25AA040/25LC040/25C040
3.5 Read Status Register (RDSR) 3.6 Write Status Register (WRSR)
The RDSR instruction provides access to the Status The WRSR instruction allows the user to select one of
register. The Status register may be read at any time, four levels of protection for the array by writing to the
even during a write cycle. The Status register is appropriate bits in the Status register. The array is
formatted as follows: divided up into four segments. The user has the ability
to write-protect none, one, two, or all four of the
7 6 5 4 3 2 1 0
segments of the array. The partitioning is controlled as
X X X X BP1 BP0 WEL WIP illustrated in Table 3-2.
The Write-In-Process (WIP) bit indicates whether the See Figure 3-7 for WRSR timing sequence.
25XX040 is busy with a write operation. When set to a
‘1’, a write is in progress, when set to a ‘0’, no write is
TABLE 3-2: ARRAY PROTECTION
in progress. This bit is read only.
Array Addresses
The Write Enable Latch (WEL) bit indicates the status BP1 BP0
Write-Protected
of the write enable latch. When set to a ‘1’, the latch
allows writes to the array, when set to a ‘0’, the latch 0 0 none
prohibits writes to the array. The state of this bit can upper 1/4
0 1
always be updated via the WREN or WRDI commands (0180h - 01FFh)
regardless of the state of write protection on the Status
register. This bit is read only. 1 0 upper 1/2
(0100h - 01FFh)
The Block Protection (BP0 and BP1) bits indicate
1 1 all
which blocks are currently write-protected. These bits
(0000h - 01FFh)
are set by the user issuing the WRSR instruction. These
bits are nonvolatile.
See Figure 3-6 for RDSR timing sequence.

FIGURE 3-6: READ STATUS REGISTER SEQUENCE

CS

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
SCK

instruction

SI 0 0 0 0 0 1 0 1

data from Status register

high-impedance
SO 7 6 5 4 3 2 1 0

FIGURE 3-7: WRITE STATUS REGISTER SEQUENCE

CS

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
SCK

instruction data to Status register

SI 0 0 0 0 0 0 0 1 7 6 5 4 3 2 1 0

high-impedance
SO

DS21204D-page 10  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
3.7 Data Protection 3.8 Power-On State
The following protection has been implemented to The 25XX040 powers on in the following state:
prevent inadvertent writes to the array: • The device is in low-power Standby mode
• The write enable latch is reset on power-up (CS = 1)
• A write enable instruction must be issued to set • The write enable latch is reset
the write enable latch • SO is in high-impedance state
• After a byte write, page write or Status register • A low level on CS is required to enter active state
write, the write enable latch is reset
• CS must be set high after the proper number of
clock cycles to start an internal write cycle
• Access to the array during an internal write cycle
is ignored and programming is continued
• The write enable latch is reset when the WP pin is
low

TABLE 3-3: WRITE-PROTECT FUNCTIONALITY MATRIX

WP WEL Protected Blocks Unprotected Blocks Status Register
Low X Protected Protected Protected
High 0 Protected Protected Protected
High 1 Protected Writable Writable

 2003 Microchip Technology Inc. DS21204D-page 11

25AA040/25LC040/25C040
4.0 PACKAGING INFORMATION

4.1 Package Marking Information

8-Lead PDIP (300 mil) Example:

XXXXXXXX 25AA040
XXXXXNNN I/PNNN
YYWW YYWW

8-Lead SOIC (150 mil) Example:

XXXXXXXX 25AA040
XXXXYYWW I/SNYYWW
NNN NNN

8-Lead TSSOP Example:

XXXX 5A4X
XYWW IYWW
NNN NNN

Legend: XX...X Customer specific information*

Y Year code (last digit of calendar year)
YY Year code (last 2 digits of calendar year)
WW Week code (week of January 1 is week ‘01’)
NNN Alphanumeric traceability code

Note: In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line thus limiting the number of available characters
for customer specific information.

* Standard PICmicro device marking consists of Microchip part number, year code, week code, and
traceability code. For PICmicro device marking beyond this, certain price adders apply. Please check
with your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP
price.

DS21204D-page 12  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
8-Lead Plastic Dual In-line (P) – 300 mil (PDIP)

E1

n 1

A A2

L
c
A1

β B1
p
eB B

Units INCHES* MILLIMETERS

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 8 8
Pitch p .100 2.54
Top to Seating Plane A .140 .155 .170 3.56 3.94 4.32
Molded Package Thickness A2 .115 .130 .145 2.92 3.30 3.68
Base to Seating Plane A1 .015 0.38
Shoulder to Shoulder Width E .300 .313 .325 7.62 7.94 8.26
Molded Package Width E1 .240 .250 .260 6.10 6.35 6.60
Overall Length D .360 .373 .385 9.14 9.46 9.78
Tip to Seating Plane L .125 .130 .135 3.18 3.30 3.43
Lead Thickness c .008 .012 .015 0.20 0.29 0.38
Upper Lead Width B1 .045 .058 .070 1.14 1.46 1.78
Lower Lead Width B .014 .018 .022 0.36 0.46 0.56
Overall Row Spacing § eB .310 .370 .430 7.87 9.40 10.92
Mold Draft Angle Top α 5 10 15 5 10 15
Mold Draft Angle Bottom β 5 10 15 5 10 15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-001
Drawing No. C04-018

 2003 Microchip Technology Inc. DS21204D-page 13

25AA040/25LC040/25C040
8-Lead Plastic Small Outline (SN) – Narrow, 150 mil (SOIC)

E1

D
2

B n 1

h α
45×

c
A A2

f
β L A1

Units INCHES* MILLIMETERS

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 8 8
Pitch p .050 1.27
Overall Height A .053 .061 .069 1.35 1.55 1.75
Molded Package Thickness A2 .052 .056 .061 1.32 1.42 1.55
Standoff § A1 .004 .007 .010 0.10 0.18 0.25
Overall Width E .228 .237 .244 5.79 6.02 6.20
Molded Package Width E1 .146 .154 .157 3.71 3.91 3.99
Overall Length D .189 .193 .197 4.80 4.90 5.00
Chamfer Distance h .010 .015 .020 0.25 0.38 0.51
Foot Length L .019 .025 .030 0.48 0.62 0.76
Foot Angle f 0 4 8 0 4 8
Lead Thickness c .008 .009 .010 0.20 0.23 0.25
Lead Width B .013 .017 .020 0.33 0.42 0.51
Mold Draft Angle Top α 0 12 15 0 12 15
Mold Draft Angle Bottom β 0 12 15 0 12 15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-012
Drawing No. C04-057

DS21204D-page 14  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
8-Lead Plastic Thin Shrink Small Outline (ST) – 4.4 mm (TSSOP)

E1

D
2

1
n
B

α
A

f A1 A2

β
L

Units INCHES MILLIMETERS*

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 8 8
Pitch p .026 0.65
Overall Height A .043 1.10
Molded Package Thickness A2 .033 .035 .037 0.85 0.90 0.95
Standoff § A1 .002 .004 .006 0.05 0.10 0.15
Overall Width E .246 .251 .256 6.25 6.38 6.50
Molded Package Width E1 .169 .173 .177 4.30 4.40 4.50
Molded Package Length D .114 .118 .122 2.90 3.00 3.10
Foot Length L .020 .024 .028 0.50 0.60 0.70
Foot Angle f 0 4 8 0 4 8
Lead Thickness c .004 .006 .008 0.09 0.15 0.20
Lead Width B .007 .010 .012 0.19 0.25 0.30
Mold Draft Angle Top α 0 5 10 0 5 10
Mold Draft Angle Bottom β 0 5 10 0 5 10
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.005” (0.127mm) per side.
JEDEC Equivalent: MO-153
Drawing No. C04-086

 2003 Microchip Technology Inc. DS21204D-page 15

25AA040/25LC040/25C040
APPENDIX A: REVISION HISTORY
Revision D
Corrections to Section 1.0, Electrical Characteristics.

DS21204D-page 16  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
ON-LINE SUPPORT SYSTEMS INFORMATION AND
Microchip provides on-line support on the Microchip UPGRADE HOT LINE
World Wide Web site. The Systems Information and Upgrade Line provides
The web site is used by Microchip as a means to make system users a listing of the latest versions of all of
files and information easily available to customers. To Microchip's development systems software products.
view the site, the user must have access to the Internet Plus, this line provides information on how customers
and a web browser, such as Netscape® or Microsoft® can receive the most current upgrade kits. The Hot Line
Internet Explorer. Files are also available for FTP Numbers are:
download from our FTP site. 1-800-755-2345 for U.S. and most of Canada, and
1-480-792-7302 for the rest of the world.
Connecting to the Microchip Internet
Web Site 042003
The Microchip web site is available at the following
URL:
www.microchip.com
The file transfer site is available by using an FTP ser-
vice to connect to:
ftp://ftp.microchip.com
The web site and file transfer site provide a variety of
services. Users may download files for the latest
Development Tools, Data Sheets, Application Notes,
User's Guides, Articles and Sample Programs. A vari-
ety of Microchip specific business information is also
available, including listings of Microchip sales offices,
distributors and factory representatives. Other data
available for consideration is:
• Latest Microchip Press Releases
• Technical Support Section with Frequently Asked
Questions
• Design Tips
• Device Errata
• Job Postings
• Microchip Consultant Program Member Listing
• Links to other useful web sites related to
Microchip Products
• Conferences for products, Development Systems,
technical information and more
• Listing of seminars and events

 2003 Microchip Technology Inc. DS21204D-page 17

25AA040/25LC040/25C040
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod-
uct. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation
can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150.
Please list the following information, and use this outline to provide us with your comments about this document.

To: Technical Publications Manager Total Pages Sent ________

RE: Reader Response

From: Name
Company
Address
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Telephone: (_______) _________ - _________ FAX: (______) _________ - _________
Application (optional):
Would you like a reply? Y N

Device: 25AA040/25LC040/25C040 Literature Number: DS21204D

Questions:

1. What are the best features of this document?

2. How does this document meet your hardware and software development needs?

3. Do you find the organization of this document easy to follow? If not, why?

4. What additions to the document do you think would enhance the structure and subject?

5. What deletions from the document could be made without affecting the overall usefulness?

6. Is there any incorrect or misleading information (what and where)?

7. How would you improve this document?

DS21204D-page 18  2003 Microchip Technology Inc.

 25AA040/25LC040/25C040
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO. X /XX XXX Examples:
a) 25AA040-I/P: Industrial Temp.,
Device Temperature Package Pattern
PDIP package
Range
b) 25AA040-I/SN: Industrial Temp.,
SOIC package
Device: 25AA040: 4096-bit 1.8V SPI Serial EEPROM c) 25AA040T-I/SN: Tape and Reel,
25AA040T: 4096-bit 1.8V SPI Serial EEPROM Industrial Temp., SOIC package
(Tape and Reel) d) 25AA040X-I/ST: Alternate Pinout,
25XX040X: 4096-bit 1.8V SPI Serial EEPROM Industrial Temp., TSSOP package
in alternate pinout (ST only) e) 25AA040XT-I/ST: Alternate Pinout, Tape
25AA040XT:4096-bit 1.8V SPI Serial EEPROM and Reel, Industrial Temp., TSSOP
in alternate pinout Tape and Reel package
(ST only)
25LC040: 4096-bit 2.5V SPI Serial EEPROM f) 25LC040-I/P: Industrial Temp.,
25LC040T: 4096-bit 2.5V SPI Serial EEPROM PDIP package
(Tape and Reel) g) 25LC040-I/SN: Industrial Temp.,
25LC040X: 4096-bit 2.5V SPI Serial EEPROM SOIC package
in alternate pinout (ST only) h) 25LC040T-I/SN: Tape and Reel,
25LC040XT:4096-bit 2.5V SPI Serial EEPROM Industrial Temp., SOIC package
in alternate pinout Tape and Reel i) 25LC040X-I/ST: Alternate Pinout,
(ST only) Industrial Temp., TSSOP package
25C040: 4096-bit 5.0V SPI Serial EEPROM
j) 25LC040XT-I/ST: Alternate Pinout, Tape
25C040T: 4096-bit 5.0V SPI Serial EEPROM
and Reel, Industrial Temp., TSSOP
(Tape and Reel)
package
25C040X: 4096-bit 5.0V SPI Serial EEPROM
in alternate pinout (ST only)
25C040XT: 4096-bit 5.0V SPI Serial EEPROM k) 25C040-I/P: Industrial Temp.,
in alternate pinout Tape and Reel PDIP package
(ST only) l) 25C040-I/SN: Industrial Temp.,
SOIC package
m) 25C040T-I/SN: Tape and Reel,
Temperature I = -40 °C to+85 °C Industrial Temp., SOIC package
Range: E = -40 °C to +125 °C n) 25C040X-I/ST: Alternate Pinout,
Industrial Temp., TSSOP package
Package: P = Plastic DIP (300 mil body), 8-lead o) 25C040XT-I/ST: Alternate Pinout, Tape
SN = Plastic SOIC (150 mil body), 8-lead and Reel, Industrial Temp., TSSOP
ST = Plastic TSSOP (4.4 mm body), 8-lead package
p) 25C040-E/P: Extended Temp.,
PDIP package
q) 25C040-E/SN: Extended Temp.,
SOIC package
r) 25C040T-E/SN: Tape and Reel,
Extended Temp., SOIC package
s) 25C040X-E/ST: Alternate Pinout,
Extended Temp., TSSOP package
t) 25C040XT-E/ST: Alternate Pinout, Tape
and Reel, Extended Temp., TSSOP pack-
age

 2003 Microchip Technology Inc. DS21204D-page 19

25AA040/25LC040/25C040
NOTES:

DS21204D-page 20  2003 Microchip Technology Inc.

Note the following details of the code protection feature on Microchip devices:
• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Information contained in this publication regarding device Trademarks

applications and the like is intended through suggestion only
The Microchip name and logo, the Microchip logo, Accuron,
and may be superseded by updates. It is your responsibility to
dsPIC, KEELOQ, MPLAB, PIC, PICmicro, PICSTART,
ensure that your application meets with your specifications.
PRO MATE and PowerSmart are registered trademarks of
No representation or warranty is given and no liability is
Microchip Technology Incorporated in the U.S.A. and other
assumed by Microchip Technology Incorporated with respect
countries.
to the accuracy or use of such information, or infringement of
patents or other intellectual property rights arising from such AmpLab, FilterLab, microID, MXDEV, MXLAB, PICMASTER,
use or otherwise. Use of Microchip’s products as critical com- SEEVAL and The Embedded Control Solutions Company are
ponents in life support systems is not authorized except with registered trademarks of Microchip Technology Incorporated
express written approval by Microchip. No licenses are con- in the U.S.A.
veyed, implicitly or otherwise, under any intellectual property Application Maestro, dsPICDEM, dsPICDEM.net, ECAN,
rights. ECONOMONITOR, FanSense, FlexROM, fuzzyLAB,
In-Circuit Serial Programming, ICSP, ICEPIC, microPort,
Migratable Memory, MPASM, MPLIB, MPLINK, MPSIM,
PICkit, PICDEM, PICDEM.net, PowerCal, PowerInfo,
PowerMate, PowerTool, rfLAB, rfPIC, Select Mode,
SmartSensor, SmartShunt, SmartTel and Total Endurance are
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
Serialized Quick Turn Programming (SQTP) is a service mark
of Microchip Technology Incorporated in the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2003, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.

Microchip received QS-9000 quality system

certification for its worldwide headquarters,
design and wafer fabrication facilities in
Chandler and Tempe, Arizona in July 1999
and Mountain View, California in March 2002.
The Company’s quality system processes and
procedures are QS-9000 compliant for its
PICmicro® 8-bit MCUs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals,
non-volatile memory and analog products. In
addition, Microchip’s quality system for the
design and manufacture of development
systems is ISO 9001 certified.

 2003 Microchip Technology Inc. DS21204D-page 21

 WORLDWIDE SALES AND SERVICE
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Tel: 81-45-471- 6166 Fax: 81-45-471-6122 07/28/03

DS21204D-page 22  2003 Microchip Technology Inc.