25AA320A/25LC320A
32K SPI Bus Serial EEPROM
Device Selection Table
Part Number
VCC Range
Page Size
Temperature Ranges
25AA320A
1.8V-5.5V
32 Byte
I
MS, P, SN, MNY, ST
25LC320A
2.5V-5.5V
32 Byte
I, E
MS, P, SN, MNY, ST
Features
Packages
Pin Function Table
• Maximum Clock 10 MHz
• Low-Power CMOS Technology:
- Maximum Write Current: 5 mA at 5.5V,
10 MHz
- Read Current: 5 mA at 5.5V, 10 MHz
- Standby Current: 5 µA at 5.5V
• 4096 x 8-bit Organization
• 32-Byte Page
• Self-Timed Erase and Write Cycles (5 ms
maximum)
• Block Write Protection:
- Protect none, 1/4, 1/2 or all of array
• Built-in Write Protection:
- Power-on/off data protection circuitry
- Write enable latch
- Write-protect pin
• Sequential Read
• High Reliability:
- Endurance: >1M erase/write cycles
- Data retention: > 200 years
- ESD protection: > 4000V
• Temperature Ranges Supported:
- Industrial (I):
-40C to +85C
- Extended (E):
-40°C to +125°C
Name
Function
CS
Chip Select Input
SO
Serial Data Output
WP
Write-Protect
VSS
Ground
SI
Serial Data Input
SCK
Serial Clock Input
HOLD
Hold Input
VCC
Supply Voltage
Description
The Microchip Technology Inc. 25AA320A/25LC320A
(25XX320A(1)) are 32-Kbit Serial Electrically Erasable
PROMs. The memory is accessed via a simple Serial
Peripheral Interface (SPI) compatible serial bus. The
bus signals required are a clock input (SCK) plus
separate data in (SI) and data out (SO) lines. Access to
the device is controlled through a Chip Select (CS)
input.
Communication to the device can be paused via the
hold pin (HOLD). While the device is paused,
transitions on its inputs will be ignored, with the
exception of Chip Select, allowing the host to service
higher priority interrupts.
• RoHS Compliant
• Automotive AEC-Q100 Qualified
Packages
Note 1: 25XX320A is used in this document as a
generic part number for the 25AA320A,
25LC320A devices.
• 8-Lead MSOP, 8-Lead PDIP, 8-Lead SOIC,
8-Lead TDFN, 8-Lead TSSOP
Package Types (not to scale)
TSSOP/MSOP
CS
SO
WP
VSS
1
2
3
4
8
7
6
5
PDIP/SOIC
VCC
HOLD
SCK
SI
CS
SO
1
2
8
7
X-Rotated TSSOP
VCC
HOLD
WP
3
6
SCK
VSS
4
5
SI
2007-2021 Microchip Technology Inc.
HOLD
VCC
CS
SO
1
2
3
4
8
7
6
5
SCK
SI
VSS
WP
TDFN
CS
SO
WP
VSS
1
8
2
7
3
6
4
5
VCC
HOLD
SCK
SI
DS20001828H-page 1
25AA320A/25LC320A
1.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings(†)
VCC.............................................................................................................................................................................6.5V
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):
Extended (E):
DC CHARACTERISTICS
Param.
Symbol
No.
D001
VIH1
D002
VIL1
D003
VIL2
D004
VOL
D005
VOL
Characteristic
High-level input voltage
Low-level input
voltage
Low-level output voltage
Minimum
TA = -40°C to +85°C
TA = -40°C to +125°C
VCC = 1.8V to 5.5V
VCC = 2.5V to 5.5V
Maximum
Units
Test Conditions
0.7 VCC
VCC+1
V
-0.3
0.3 VCC
V
VCC2.7V
-0.3
0.2 VCC
V
VCC < 2.7V
—
0.4
V
IOL = 2.1 mA
—
0.2
V
IOL = 1.0 mA, VCC < 2.5V
D006
VOH
High-level output voltage
VCC -0.5
—
V
IOH = -400 µA
D007
ILI
Input leakage current
—
±1
µA
CS = VCC, VIN = VSS TO VCC
D008
ILO
Output leakage current
—
±1
µA
CS = VCC, VOUT = VSS TO VCC
D009
CINT
Internal Capacitance
(all inputs and outputs)
—
7
pF
TA = +25°C, CLK = 1.0 MHz,
VCC = 5.0V (Note 1)
—
5
mA
VCC = 5.5V; FCLK = 10.0 MHz;
SO = Open
—
2.5
mA
VCC = 2.5V; FCLK = 5.0 MHz;
SO = Open
—
5
mA
VCC = 5.5V
—
3
mA
VCC = 2.5V
—
5
µA
CS = VCC = 5.5V, Inputs tied to
VCC or VSS, +125°C
—
1
µA
CS = VCC = 5.5V, Inputs tied to
VCC or VSS, +85°C
D010
ICC Read
Operating Current
D011
D012
Note 1:
ICC Write
ICCS
Standby Current
This parameter is periodically sampled and not 100% tested.
DS20001828H-page 2
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
TABLE 1-2:
AC CHARACTERISTICS
Param.
Symbol
No.
1
FCLK
2
TCSS
3
TCSH
4
TCSD
5
Tsu
Characteristic
Clock Frequency
CS Setup Time
CS Hold Time
CS Disable Time
Data Setup Time
6
THD
Data Hold Time
7
TR
CLK rise time
8
TF
CLK fall time
9
THI
TA = -40°C to +85°C
TA = -40°C to +125°C
Industrial (I):
Extended (E):
AC CHARACTERISTICS
Clock high time
Minimum Maximum
Units
VCC = 1.8V to 5.5V
VCC = 2.5V to 5.5V
Test Conditions
—
10
MHz
4.5V Vcc 5.5V
—
5
MHz
2.5V Vcc 4.5V
—
3
MHz
1.8V Vcc 2.5V
50
—
ns
4.5V Vcc 5.5V
100
—
ns
2.5V Vcc 4.5V
150
—
ns
1.8V Vcc 2.5V
100
—
ns
4.5V Vcc 5.5V
200
—
ns
2.5V Vcc 4.5V
250
—
ns
1.8V Vcc 2.5V
50
—
ns
10
—
ns
4.5V Vcc 5.5V
20
—
ns
2.5V Vcc 4.5V
30
—
ns
1.8V Vcc 2.5V
20
—
ns
4.5V Vcc 5.5V
40
—
ns
2.5V Vcc 4.5V
50
—
ns
1.8V Vcc 2.5V
—
2
µs
Note 1
—
2
µs
Note 1
50
—
ns
4.5V Vcc 5.5V
100
—
ns
2.5V Vcc 4.5V
150
—
ns
1.8V Vcc 2.5V
50
—
ns
4.5V Vcc 5.5V
100
—
ns
2.5V Vcc 4.5V
150
—
ns
1.8V Vcc 2.5V
50
—
ns
10
TLO
Clock Low Time
11
TCLD
Clock Delay Time
12
TCLE
Clock Enable Time
50
—
ns
—
50
ns
4.5V Vcc 5.5V
—
100
ns
2.5V Vcc 4.5V
—
160
ns
1.8V Vcc 2.5V
0
—
ns
Note 1
—
40
ns
4.5V Vcc 5.5V(Note 1)
—
80
ns
2.5V Vcc 4.5V(Note 1)
—
160
ns
1.8V Vcc 2.5V(Note 1)
20
—
ns
4.5V Vcc 5.5V
40
—
ns
2.5V Vcc 4.5V
80
—
ns
1.8V Vcc 2.5V
13
TV
14
THO
15
TDIS
16
THS
Note 1:
2:
3:
Output Valid From Clock Low
Output Hold Time
Output Disable Time
HOLD Setup Time
This parameter is periodically sampled and not 100% tested.
TWC begins on the rising edge of CS after a valid write sequence and ends when the internal write cycle is
complete.
This parameter is not tested but ensured by characterization.
2007-2021 Microchip Technology Inc.
DS20001828H-page 3
25AA320A/25LC320A
TABLE 1-2:
AC CHARACTERISTICS (CONTINUED)
Param.
Symbol
No.
17
THH
18
THZ
19
THV
20
TWC
21
Characteristic
Minimum Maximum
HOLD Hold Time
HOLD Low to Output High-Z
HOLD High to Output Valid
Internal Write Cycle Time
Endurance
Note 1:
2:
3:
TA = -40°C to +85°C
TA = -40°C to +125°C
Industrial (I):
Extended (E):
AC CHARACTERISTICS
Units
VCC = 1.8V to 5.5V
VCC = 2.5V to 5.5V
Test Conditions
20
—
ns
4.5V Vcc 5.5V
40
—
ns
2.5V Vcc 4.5V
80
—
ns
1.8V Vcc 2.5V
—
30
ns
4.5V Vcc 5.5V(Note 1)
—
60
ns
2.5V Vcc 4.5V(Note 1)
—
160
ns
1.8V Vcc 2.5V(Note 1)
—
30
ns
4.5V Vcc 5.5V
—
60
ns
2.5V Vcc 4.5V
—
160
ns
1.8V Vcc 2.5V
—
5
ms
(Note 2)
1M
—
+25°C, 5.5V, Page Mode
E/W Cycles
(Note 3)
This parameter is periodically sampled and not 100% tested.
TWC begins on the rising edge of CS after a valid write sequence and ends when the internal write cycle is
complete.
This parameter is not tested but ensured by characterization.
TABLE 1-3:
AC TEST CONDITIONS
AC Waveform:
VLO = 0.2V
—
VH I = VCC - 0.2V
Note 1
VH I = 4.0V
Note 2
CL = 50 pF
—
Timing Measurement Reference Level
Input
0.5 VCC
Output
Note 1:
2:
0.5 VCC
For VCC 4.0V
For VCC > 4.0V
DS20001828H-page 4
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
FIGURE 1-1:
HOLD TIMING
CS
17
16
17
16
SCK
18
SO
n+2
SI
n+2
n+1
n
19
High-Impedance
n
5
Don’t Care
n+1
n-1
n
n
n-1
HOLD
FIGURE 1-2:
SERIAL INPUT TIMING
4
CS
2
7
Mode 1,1
8
3
12
11
SCK Mode 0,0
5
SI
6
MSB in
LSB in
High-Impedance
SO
FIGURE 1-3:
SERIAL OUTPUT TIMING
CS
9
3
10
Mode 1,1
SCK
Mode 0,0
13
SO
14
MSB out
SI
2007-2021 Microchip Technology Inc.
15
LSB out
Don’t Care
DS20001828H-page 5
25AA320A/25LC320A
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
Name
CS
PIN FUNCTION TABLE
MSSOP
PDIP
SOIC
TDFN
TSSOP
X-Rotated TSSOP
1
1
1
1
1
3
Function
Chip Select Input
SO
2
2
2
2
2
4
Serial Data Output
WP
3
3
3
3
3
5
Write-Protect Pin
VSS
4
4
4
4
4
6
Ground
SI
5
5
5
5
5
7
Serial Data Input
SCK
6
6
6
6
6
8
Serial Clock Input
HOLD
7
7
7
7
7
1
Hold Input
8
8
8
8
8
2
Supply Voltage
VCC
Note 1:
2.1
The exposed pad on the TDFN package can be connected to VSS or left floating.
Chip Select (CS)
A low level on this pin selects the device. A high level
deselects the device and forces it into Standby mode.
However, a programming cycle which is already
initiated or in progress will be completed, regardless of
the CS input signal. If CS is brought high during a
program cycle, the device will go into Standby mode as
soon as the programming cycle is complete. When the
device is deselected, SO goes to the high-impedance
state, allowing multiple parts to share the same SPI
bus. A low-to-high transition on CS after a valid write
sequence initiates an internal write cycle. After
power-up, a low level on CS is required prior to any
sequence being initiated.
2.2
Serial Output (SO)
The SO pin is used to transfer data out of the
25XX320A. During a read cycle, data are shifted out on
this pin after the falling edge of the serial clock.
2.3
Write-Protect (WP)
This pin is used in conjunction with the WPEN bit in the
STATUS register to prohibit writes to the nonvolatile
bits in the STATUS register. When WP is low and
WPEN is high, writing to the nonvolatile bits in the
STATUS register is disabled. All other operations
function normally. When WP is high, all functions,
including writes to the nonvolatile bits in the STATUS
register operate normally. If the WPEN bit is set, WP
low during a STATUS register write sequence will
disable writing to the STATUS register. If an internal
write cycle has already begun, WP going low will have
no effect on the write. The WP pin function is blocked
when the WPEN bit in the STATUS register is low. This
allows the user to install the 25XX320A in a system with
WP pin grounded and still be able to write to the
STATUS register. The WP pin functions will be enabled
when the WPEN bit is set high.
DS20001828H-page 6
2.4
Serial Input (SI)
The SI pin is used to transfer data into the device. It
receives instructions, addresses and data. Data are
latched on the rising edge of the serial clock.
2.5
Serial Clock (SCK)
The SCK is used to synchronize the communication
between a host and the 25XX320A. Instructions,
addresses or data present on the SI pin are latched on
the rising edge of the clock input, while data on the SO
pin is updated after the falling edge of the clock input.
2.6
Hold (HOLD)
The HOLD pin is used to suspend transmission to the
25XX320A while in the middle of a serial sequence
without having to retransmit the entire sequence again.
It must be held high any time this function is not being
used. Once the device is selected and a serial
sequence is underway, the HOLD pin may be pulled
low to pause further serial communication without
resetting the serial sequence.
The HOLD pin must be brought low while SCK is low,
otherwise the HOLD function will not be invoked until
the next SCK high-to-low transition. The 25XX320A
must remain selected during this sequence. The SI and
SCK levels are “don’t cares” during the time the device
is paused and any transitions on these pins will be
ignored. To resume serial communication, HOLD must
be brought high while the SCK pin is low; otherwise
serial communication will not be resumed until the next
SCK high-to-low transition.
The SO line will tri-state immediately upon a
high-to-low transition of the HOLD pin and will begin
outputting again immediately upon a subsequent
low-to-high transition of the HOLD pin, independent of
the state of SCK.
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
3.0
FUNCTIONAL DESCRIPTION
3.1
Principles of Operation
BLOCK DIAGRAM
STATUS
Register
The 25XX320A is a 4096-byte Serial EEPROM
designed to interface directly with the Serial Peripheral
Interface (SPI) port of many of today’s popular
microcontroller families, including Microchip’s PIC®
microcontrollers. It may also interface with
microcontrollers that do not have a built-in SPI port by
using discrete I/O lines programmed properly in
firmware to match the SPI protocol.
The 25XX320A contains an 8-bit instruction register.
The device is accessed via the SI pin, with data being
clocked in on the rising edge of SCK. The CS pin must
be low and the HOLD pin must be high for the entire
operation.
Table 3-1 contains a list of the possible instruction
bytes and format for device operation. All instructions,
addresses and data are transferred MSB first, LSB last.
I/O Control
Logic
Memory
Control
Logic
EEPROM
Array
X
Dec
Page Latches
SI
SO
Y Decoder
CS
SCK
Sense Amp.
R/W Control
HOLD
WP
Data (SI) are sampled on the first rising edge of SCK
after CS goes low. If the clock line is shared with other
peripheral devices on the SPI bus, the user can assert
the HOLD input and place the 25XX320A in ‘HOLD’
mode. After releasing the HOLD pin, operation will
resume from the point when the HOLD was asserted.
TABLE 3-1:
HV Generator
VCC
VSS
INSTRUCTION SET
Instruction Name
Instruction Format
READ
0000 0011
Read data from memory array beginning at selected address
WRITE
0000 0010
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
2007-2021 Microchip Technology Inc.
Description
DS20001828H-page 7
25AA320A/25LC320A
3.2
Read Sequence
Once the write enable latch is set, the user may
proceed by setting the CS low, issuing a WRITE
instruction, followed by the 16-bit address, with the four
MSBs of the address being “don’t care” bits, and then
the data to be written. Up to 32 bytes of data can be
sent to the device before a write cycle is necessary.
The only restriction is that all of the bytes must reside
in the same page.
The device is selected by pulling CS low. The 8-bit
READ instruction is transmitted to the 25XX320A
followed by the 16-bit address, with the four MSBs of
the address being “don’t care” bits. After the correct
READ instruction and address are sent, the data stored
in the memory at the selected address are shifted out
on the SO pin. The data stored in the memory at the
next address can be read sequentially by continuing to
provide clock pulses. The internal Address Pointer is
automatically incremented to the next higher address
after each byte of data are shifted out. When the
highest address is reached (0FFFh), 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).
3.3
Note:
Page write operations are limited to
writing bytes within a single physical page,
regardless of the number of bytes
actually being written. Physical page
boundaries start at addresses that are
integer multiples of the page buffer size
(or ‘page size’) and end at addresses that
are integer multiples of page size – 1. If a
Page Write command attempts to write
across a physical page boundary, the
result is that the data wrap around to the
beginning of the current page (overwriting
data previously stored there), instead of
being written to the next page as might be
expected. It is therefore necessary for the
application software to prevent page write
operations that would attempt to cross a
page boundary.
Write Sequence
Prior to any attempt to write data to the 25XX320A, the
write enable latch must be set by issuing the WREN
instruction (Figure 3-4). This is done by setting CS low
and then clocking out the proper instruction into the
25XX320A. After all eight bits of the instruction are
transmitted, the CS must be brought high to set the
write enable latch. If the write operation is initiated
immediately after the WREN instruction without CS
being brought high, the data will not be written to the
array because the write enable latch will not have been
properly set.
FIGURE 3-1:
For the data to be actually written to the array, the CS
must be brought high after the Least Significant bit (D0)
of the nth data byte has been clocked in. If CS is
brought high at any other time, the write operation will
not be completed. Refer to Figure 3-2 and Figure 3-3
for more detailed illustrations on the byte write
sequence and the page write sequence, respectively.
While the write is in progress, the STATUS register may
be read to check the status of the WPEN, WIP, WEL,
BP1 and BP0 bits (Figure 3-6). A read attempt of a
memory array location will not be possible during a
write cycle. When the write cycle is completed, the
write enable latch is reset.
READ SEQUENCE
CS
0
1
2
3
4
5
6
7
8
9 10 11
21 22 23 24 25 26 27 28 29 30 31
SCK
Instruction
SI
0
0
0
0
0
16-bit Address
0
1
1 15 14 13 12
2
1
0
Data Out
High-Impedance
SO
DS20001828H-page 8
7
6
5
4
3
2
1
0
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
FIGURE 3-2:
BYTE WRITE SEQUENCE
CS
(1)
Twc
0
1
2
3
4
5
6
8
7
9 10 11
21 22 23 24 25 26 27 28 29 30 31
SCK
Instruction
SI
0
0
0
0
0
16-bit Address
0
1
Data Byte
2
0 15 14 13 12
1
0
7
6
5
4
3
2
1
0
High-Impedance
SO
Note 1: This sequence initiates a self-timed internal write cycle on the rising edge of CS after a valid sequence.
FIGURE 3-3:
PAGE WRITE SEQUENCE
CS
0
1
2
3
4
5
6
7
8
9 10 11
21 22 23 24 25 26 27 28 29 30 31
SCK
Instruction
SI
0
0
0
0
0
16-bit Address
0 1
0 15 14 13 12
Data Byte 1
2
1
0
7
6
5
4
3
2
1
0
CS
(1)
Twc
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
SCK
Data Byte 2
SI
7
6
5
4
3
2
Data Byte 3
1
0
7
6
5
4
3
2
Data Byte n (32 max)
1
0
7
6
5
4
3
2
1
0
Note 1: This sequence initiates a self-timed internal write cycle on the rising edge of CS after a valid sequence.
2007-2021 Microchip Technology Inc.
DS20001828H-page 9
25AA320A/25LC320A
3.4
Write Enable (WREN) and Write
Disable (WRDI)
The following is a list of conditions under which the
write enable latch will be reset:
•
•
•
•
The 25XX320A contains a write enable latch. See
Table 3-4 for the write-protect functionality matrix. This
latch must be set before any write operation will be
completed internally. The WREN instruction will set the
latch, and the WRDI will reset the latch.
FIGURE 3-4:
Power-up
WRDI instruction successfully executed
WRSR instruction successfully executed
WRITE instruction successfully executed
WRITE ENABLE SEQUENCE (WREN)
CS
0
1
2
3
4
5
6
7
SCK
0
SI
0
0
0
1
1
0
High-Impedance
SO
FIGURE 3-5:
0
WRITE DISABLE SEQUENCE (WRDI)
CS
0
1
2
3
4
5
6
7
SCK
SI
0
0
0
0
0
1
10
0
High-Impedance
SO
DS20001828H-page 10
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
Read STATUS Register
Instruction (RDSR)
3.5
The Write Enable Latch (WEL) bit indicates the status
of the write enable latch and is read-only. When set to
a ‘1’, the latch allows writes to the array, when set to
a ‘0’, the latch prohibits writes to the array. The state of
this bit can always be updated via the WREN or WRDI
commands, regardless of the state of write protection
on the STATUS register. These commands are shown
in Figure 3-4 and Table 3-5.
The Read STATUS Register instruction (RDSR)
provides access to the STATUS register. The STATUS
register may be read at any time, even during a write
cycle. The STATUS register is formatted as follows:
TABLE 3-2:
The Block Protection (BP0 and BP1) bits indicate
which blocks are currently write-protected. These bits
are set by the user issuing the WRSR instruction. These
bits are nonvolatile and are shown in Table 3-3.
STATUS REGISTER
7
6
5
4
3
2
1
0
W/R
–
–
–
W/R
W/R
R
R
WPEN
X
X
X
BP1
BP0
WEL
WIP
Note 1:
See Figure 3-6 for the RDSR timing sequence.
W/R = writable/readable. R = read-only.
The Write-In-Process (WIP) bit indicates whether the
25XX320A is busy with a write operation. When set to
a ‘1’, a write is in progress, when set to a ‘0’, no write
is in progress. This bit is read-only.
FIGURE 3-6:
READ STATUS REGISTER TIMING SEQUENCE (RDSR)
CS
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
0
SCK
Instruction
SI
0
0
0
0
0
High-Impedance
SO
2007-2021 Microchip Technology Inc.
1
0
1
Data from STATUS Register
7
6
5
4
3
2
DS20001828H-page 11
25AA320A/25LC320A
3.6
Write STATUS Register Instruction
(WRSR)
See Figure 3-7 for the WRSR timing sequence.
TABLE 3-3:
The Write STATUS Register instruction (WRSR) allows
the user to write to the nonvolatile bits in the STATUS
register as shown in Table 3-2. The user is able to
select one of four levels of protection for the array by
writing to the appropriate bits in the STATUS register.
The array is divided up into four segments. The user
has the ability to write-protect none, one, two or all four
of the segments of the array. The partitioning is
controlled as shown in Table 3-3.
BP1
BP0
Array Addresses
Write-Protected
0
0
none
0
1
upper 1/4
(0C00h-0FFFh)
1
0
upper 1/2
(0800h-0FFFh)
1
1
all
(0000h-0FFFh)
The Write-Protect Enable (WPEN) bit is a nonvolatile
bit that is available as an enable bit for the WP pin. The
Write-Protect (WP) pin and the Write-Protect Enable
(WPEN) bit in the STATUS register control the
programmable
hardware
write-protect
feature.
Hardware write protection is enabled when WP pin is
low and the WPEN bit is high. Hardware write
protection is disabled when either the WP pin is high or
the WPEN bit is low. When the chip is hardware
write-protected, only writes to nonvolatile bits in the
STATUS register are disabled. See Table 3-4 for a
matrix of functionality on the WPEN bit.
TABLE 3-4:
ARRAY PROTECTION
WRITE-PROTECT FUNCTIONALITY MATRIX
WEL
(SR bit 1)
WPEN
(SR bit 7)
WP
(pin 3)
Protected Blocks
Unprotected Blocks
STATUS Register
0
x
x
Protected
Protected
Protected
1
0
x
Protected
Writable
Writable
1
1
0 (low)
Protected
Writable
Protected
1
1
1 (high)
Protected
Writable
Writable
Note 1:
x = don’t care
FIGURE 3-7:
WRITE STATUS REGISTER TIMING SEQUENCE (WRSR)
CS
Twc
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
0
(1)
SCK
Instruction
SI
0
0
0
0
Data to STATUS Register
0
0
0
1
7
6
5
4
3
2
High-Impedance
SO
Note 1:
This sequence initiates a self-timed internal write cycle on the rising edge of CS after a valid sequence.
DS20001828H-page 12
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
4.0
DATA PROTECTION
The following protection has been implemented to
prevent inadvertent writes to the array:
• The write enable latch is reset on power-up
• A write enable instruction must be issued to set
the write enable latch
• After a byte write, page write or STATUS register
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
2007-2021 Microchip Technology Inc.
5.0
POWER-ON STATE
The 25XX320A powers on in the following state:
• The device is in low-power Standby mode
(CS = 1)
• The write enable latch is reset
• SO is in high-impedance state
• A high-to-low-level transition on CS is required to
enter active state
DS20001828H-page 13
25AA320A/25LC320A
6.0
PACKAGING INFORMATION
6.1
Package Marking Information
8-Lead MSOP (150 mil)
XXXXXT
YWWNNN
5LBAI
1251L7
8-Lead PDIP
Example:
XXXXXXXX
T/XXXNNN
YYWW
25LC320A
I/P e3 1L7
2125
8-Lead SOIC
Example:
XXXXXXXT
XXXXYYWW
NNN
25LC32AI
SN e3 2125
1L7
8-Lead TSSOP
Example:
XXXX
TYWW
NNN
8-Lead 2x3 TDFN
XXX
YWW
NN
DS20001828H-page 14
Example:
5LBA
I125
1L7
Example:
C71
125
17
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
1st Line Marking Codes
TDFN
MSOP
SOIC
TSSOP
Rotated
TSSOP
I Temp.
E Temp.
25AA320A
5ABAT
25AA32AT
5ABA
LBAX
C71
—
25LC320A
5LBAT
25LC32AT
5LBA
LBAX
C74
C75
Part Number
Legend: XX...X
T
Y
YY
WW
NNN
e3
Customer-specific information
Temperature grade (I, E)
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
RoHS-compliant JEDEC® designator for Matte Tin (Sn)
Note:
For very small packages with no room for the RoHS-compliant JEDEC®
designator e3 , the marking will only appear on the outer carton or reel label.
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.
2007-2021 Microchip Technology Inc.
DS20001828H-page 15
25AA320A/25LC320A
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
DS20001828H-page 16
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
2007-2021 Microchip Technology Inc.
DS20001828H-page 17
25AA320A/25LC320A
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
DS20001828H-page 18
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
8-Lead Plastic Dual In-Line (P) - 300 mil Body [PDIP]
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
D
A
N
B
E1
NOTE 1
1
2
TOP VIEW
E
C
A2
A
PLANE
L
c
A1
e
eB
8X b1
8X b
.010
C
SIDE VIEW
END VIEW
Microchip Technology Drawing No. C04-018-P Rev E Sheet 1 of 2
2007-2021 Microchip Technology Inc.
DS20001828H-page 19
25AA320A/25LC320A
8-Lead Plastic Dual In-Line (P) - 300 mil Body [PDIP]
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
ALTERNATE LEAD DESIGN
(NOTE 5)
DATUM A
DATUM A
b
b
e
2
e
2
e
e
Units
Dimension Limits
Number of Pins
N
e
Pitch
Top to Seating Plane
A
Molded Package Thickness
A2
Base to Seating Plane
A1
Shoulder to Shoulder Width
E
Molded Package Width
E1
Overall Length
D
Tip to Seating Plane
L
c
Lead Thickness
b1
Upper Lead Width
b
Lower Lead Width
eB
§
Overall Row Spacing
MIN
.115
.015
.290
.240
.348
.115
.008
.040
.014
-
INCHES
NOM
8
.100 BSC
.130
.310
.250
.365
.130
.010
.060
.018
-
MAX
.210
.195
.325
.280
.400
.150
.015
.070
.022
.430
Notes:
1. Pin 1 visual index feature may vary, but must be located within the hatched area.
2. § Significant Characteristic
3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or
protrusions shall not exceed .010" per side.
4. Dimensioning and tolerancing per ASME Y14.5M
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
5. Lead design above seating plane may vary, based on assembly vendor.
Microchip Technology Drawing No. C04-018-P Rev E Sheet 2 of 2
DS20001828H-page 20
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC]
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
2X
0.10 C A–B
D
A
D
NOTE 5
N
E
2
E1
2
E1
E
2X
0.10 C A–B
2X
0.10 C A–B
NOTE 1
2
1
e
B
NX b
0.25
C A–B D
NOTE 5
TOP VIEW
0.10 C
C
A A2
SEATING
PLANE
8X
A1
SIDE VIEW
0.10 C
h
R0.13
h
R0.13
H
SEE VIEW C
VIEW A–A
0.23
L
(L1)
VIEW C
Microchip Technology Drawing No. C04-057-SN Rev F Sheet 1 of 2
2007-2021 Microchip Technology Inc.
DS20001828H-page 21
25AA320A/25LC320A
8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC]
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Units
Dimension Limits
Number of Pins
N
e
Pitch
Overall Height
A
Molded Package Thickness
A2
§
Standoff
A1
Overall Width
E
Molded Package Width
E1
Overall Length
D
Chamfer (Optional)
h
Foot Length
L
Footprint
L1
Foot Angle
c
Lead Thickness
b
Lead Width
Mold Draft Angle Top
Mold Draft Angle Bottom
MIN
1.25
0.10
0.25
0.40
0°
0.17
0.31
5°
5°
MILLIMETERS
NOM
8
1.27 BSC
6.00 BSC
3.90 BSC
4.90 BSC
1.04 REF
-
MAX
1.75
0.25
0.50
1.27
8°
0.25
0.51
15°
15°
Notes:
1. Pin 1 visual index feature may vary, but must be located within the hatched area.
2. § Significant Characteristic
3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or
protrusions shall not exceed 0.15mm per side.
4. Dimensioning and tolerancing per ASME Y14.5M
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
REF: Reference Dimension, usually without tolerance, for information purposes only.
5. Datums A & B to be determined at Datum H.
Microchip Technology Drawing No. C04-057-SN Rev F Sheet 2 of 2
DS20001828H-page 22
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC]
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
SILK SCREEN
C
Y1
X1
E
RECOMMENDED LAND PATTERN
Units
Dimension Limits
E
Contact Pitch
Contact Pad Spacing
C
Contact Pad Width (X8)
X1
Contact Pad Length (X8)
Y1
MIN
MILLIMETERS
NOM
1.27 BSC
5.40
MAX
0.60
1.55
Notes:
1. Dimensioning and tolerancing per ASME Y14.5M
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
Microchip Technology Drawing C04-2057-SN Rev F
2007-2021 Microchip Technology Inc.
DS20001828H-page 23
25AA320A/25LC320A
8-Lead Plastic Dual Flat, No Lead Package (MNY) – 2x3x0.8 mm Body [TDFN]
With 1.4x1.3 mm Exposed Pad (JEDEC Package type WDFN)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
D
A
B
N
(DATUM A)
(DATUM B)
E
NOTE 1
2X
0.15 C
1
2
2X
0.15 C
TOP VIEW
0.10 C
C
(A3)
A
SEATING
PLANE
8X
0.08 C
A1
SIDE VIEW
0.10
C A B
D2
L
1
2
0.10
C A B
NOTE 1
E2
K
N
8X b
e
0.10
0.05
C A B
C
BOTTOM VIEW
Microchip Technology Drawing No. C04-129-MNY Rev E Sheet 1 of 2
DS20001828H-page 24
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
8-Lead Plastic Dual Flat, No Lead Package (MNY) – 2x3x0.8 mm Body [TDFN]
With 1.4x1.3 mm Exposed Pad (JEDEC Package type WDFN)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Units
Dimension Limits
N
Number of Pins
e
Pitch
A
Overall Height
A1
Standoff
Contact Thickness
A3
D
Overall Length
E
Overall Width
Exposed Pad Length
D2
Exposed Pad Width
E2
b
Contact Width
L
Contact Length
Contact-to-Exposed Pad
K
MIN
0.70
0.00
1.35
1.25
0.20
0.25
0.20
MILLIMETERS
NOM
8
0.50 BSC
0.75
0.02
0.20 REF
2.00 BSC
3.00 BSC
1.40
1.30
0.25
0.30
-
MAX
0.80
0.05
1.45
1.35
0.30
0.45
-
Notes:
1. Pin 1 visual index feature may vary, but must be located within the hatched area.
2. Package may have one or more exposed tie bars at ends.
3. Package is saw singulated
4. Dimensioning and tolerancing per ASME Y14.5M
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
REF: Reference Dimension, usually without tolerance, for information purposes only.
Microchip Technology Drawing No. C04-129-MNY Rev E Sheet 2 of 2
2007-2021 Microchip Technology Inc.
DS20001828H-page 25
25AA320A/25LC320A
8-Lead Plastic Dual Flat, No Lead Package (MNY) – 2x3x0.8 mm Body [TDFN]
With 1.4x1.3 mm Exposed Pad (JEDEC Package type WDFN)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
X2
EV
8
ØV
C
Y2
EV
Y1
1
2
SILK SCREEN
X1
E
RECOMMENDED LAND PATTERN
Units
Dimension Limits
E
Contact Pitch
Optional Center Pad Width
X2
Optional Center Pad Length
Y2
Contact Pad Spacing
C
Contact Pad Width (X8)
X1
Contact Pad Length (X8)
Y1
Thermal Via Diameter
V
Thermal Via Pitch
EV
MIN
MILLIMETERS
NOM
0.50 BSC
MAX
1.60
1.50
2.90
0.25
0.85
0.30
1.00
Notes:
1. Dimensioning and tolerancing per ASME Y14.5M
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
2. For best soldering results, thermal vias, if used, should be filled or tented to avoid solder loss during
reflow process
Microchip Technology Drawing No. C04-129-MNY Rev. B
DS20001828H-page 26
2007-2021 Microchip Technology Inc.
25AA320A/25LC320A
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2007-2021 Microchip Technology Inc.
DS20001828H-page 27
25AA320A/25LC320A
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