MICROCHIP 25AA160A, 25AA160B, 25LC160A, 25LC160B Technical data

25AA160A/B, 25LC160A/B

16K SPI™ Bus Serial EEPROM

Device Selection Table

Part Number VCC Range Page Size Temp. Ranges Packages

25LC160A 2.5-5.5V 16 Byte I,E P, SN, ST, MS

25AA160A 1.8-5.5V 16 Byte I P, SN, ST, MS

25LC160B 2.5-5.5V 32 Byte I,E P, SN, ST, MS

25AA160B 1.8-5.5V 32 Byte I P, SN, ST, MS

Features

• Max. clock 10 MHz

• Low-power CMOS technology

• 2048 x 8-bit organization

• 16 byte page (‘A’ version devices)

• 32 byte page (‘B’ version devices)

• Write cycle time: 5 ms max.

• Self-timed ERASE and WRITE cycles

• 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: 1,000,000 erase/write cycles

- Data retention: > 200 years

- ESD protection: > 4000V

• Temperature ranges supported;

- Industrial (I): -40°Cto +85°C

- Automotive (E): -40°C to +125°C

Pin Function Table

Name Function

Description

The Microchip Technology Inc. 25AA160A/B,
25LC160A/B (25XX160A/B
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

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.

The 25XX160A/B is available in standard packages
including 8-lead PDIP and SOIC, and advanced
packaging including 8-lead MSOP, and 8-lead TSSOP.
Pb-free (Pure Matte Sn) finish is also available.

*

) are 16 Kbit Serial

) input.

Package Types (not to scale)

CS
SO

WP

V

SS

PDIP/SOIC

(P, SN)

1

8

2

7

3

6

4

5

V

CC

HOLD

SCK

SI

TSSOP/MSOP

(ST, MS)

1

CS

2

SO

3

WP

4

V

SS

8

V

CC

7

HOLD

6

SCK

5

SI

CS

Chip Select Input

SPI is a registered trademark of Motorola Semiconductor.

SO Serial Data Output

WP

SS Ground

V

Write-Protect

SI Serial Data Input

SCK Serial Clock Input

HOLD

V

CC Supply Voltage

 2003 Microchip Technology Inc. DS21807B-page 1

Hold Input

*25XX160A/B is used in this document as a generic part
number for the 25AA160A/B, 25LC160A/B devices.

25XX160A/B

1.0 ELECTRICAL CHARACTERISTICS

Absolute Maximum Ratings

(†)

VCC.............................................................................................................................................................................7.0V

All inputs and outputs w.r.t. V

SS ......................................................................................................... -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

DC CHARACTERISTICS

Param.

No.

D001 V

D002 V

D003 V

D004 V

D005 V

D006 V

D007 V

Sym. Characteristic Min. Max. Units Test Conditions

IH1 High-level input

IH2 0.7 VCC VCC +1 V VCC< 2.7V (Note)

IL1 Low-level input

IL2 -0.3 0.2 VCC VVCC < 2.7V (Note)

OL Low-level output

OL —0.2VIOL = 1.0 mA, VCC < 2.5V

OH High-level output

voltage

voltage

voltage

Industrial (I): T
Automotive (E): T

2.0 VCC +1 V VCC ≥ 2.7V (Note)

-0.3 0.8 V VCC ≥ 2.7V (Note)

—0.4VIOL = 2.1 mA

VCC -0.5 — V IOH = -400 µA

voltage

D008 I

LI Input leakage current ±1 µACS = VCC, VIN = VSS TO VCC

D009 ILO Output leakage

current

D010 CINT Internal Capacitance

— 7 pF T
(all inputs and
outputs)

D011 I

CC Read

—

—
Operating Current

D012 I

D013 I

CC Write — 3 mA VCC = 5.5V

CCS

Standby Current

—

—

Note: This parameter is periodically sampled and not 100% tested.

AMB = -40°C to +85°C VCC = 1.8V to 5.5V
AMB = -40°C to +125°C VCC = 2.5V to 5.5V

±1 µACS = VCC, VOUT = VSS TO VCC

AMB = 25°C, CLK = 1.0 MHz,

CC = 5.0V (Note)

V

6

mAmAVCC = 5.5V; FCLK = 10.0 MHz;

SO = Open

2.5

V

CC = 2.5V; FCLK = 5.0 MHz;

SO = Open

5

1

µAµACS

V
CS
V

= VCC = 5.5V, Inputs tied to VCC or

SS, TAMB = -40°C TO +125°C

= VCC = 2.5V, Inputs tied to VCC or

SS, TAMB = -40°C TO +85°C

DS21807B-page 2  2003 Microchip Technology Inc.

TABLE 1-2: AC CHARACTERISTICS

25XX160A/B

AC CHARACTERISTICS

Param.

No.

1F

Sym. Characteristic Min. Max. Units Test Conditions

CLK Clock Frequency —

Industrial (I): T
Automotive (E): T

—
—

2T

CSS CS Setup Time 50

100
150

3T

CSH CS Hold Time 100

200
250

4T

CSD CS Disable Time 50 — ns —

5 Tsu Data Setup Time 10

20
30

6T

HD Data Hold Time 20

40
50

7T

8T

9T

R CLK Rise Time — 500 ns (Note 1)

F CLK Fall Time — 500 ns (Note 1)

HI Clock High Time 50

100
150

10 T

LO Clock Low Time 50

100
150

11 T

12 T

13 T

CLD Clock Delay Time 50 — ns —

CLE Clock Enable Time 50 — ns —

V Output Valid from Clock

Low

—
—
—

14 T

15 T

HO Output Hold Time 0 — ns (Note 1)

DIS Output Disable Time —

—
—

16 T

HS HOLD Setup Time 20

40
80

AMB = -40°C to +85°C VCC = 1.8V to 5.5V
AMB = -40°C to +125°C VCC = 2.5V to 5.5V

10

5
3

—
—
—

—
—
—

—
—
—

—
—
—

—
—
—

—
—
—

50
100
160

40

80
160

—

—

—

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.

WC begins on the rising edge of CS after a valid write sequence and ends when the internal write cycle is

3: T

complete.

MHz
MHz
MHz

ns
ns
ns

ns
ns
ns

ns
ns
ns

ns
ns
ns

ns
ns
ns

ns
ns
ns

ns
ns
ns

ns
ns
ns

ns
ns
ns

4.5V ≤ VCC ≤ 5.5V

2.5V ≤ V

1.8V ≤ V

CC < 4.5V
CC < 2.5V

4.5V ≤ VCC ≤ 5.5V

2.5V ≤ V

1.8V ≤ V

CC < 4.5V
CC < 2.5V

4.5V ≤ VCC ≤ 5.5V

2.5V ≤ V

1.8V ≤ V

4.5V ≤ V

2.5V ≤ V

1.8V ≤ V

4.5V ≤ V

2.5V ≤ V

1.8V ≤ V

CC < 4.5V
CC < 2.5V

CC ≤ 5.5V
CC < 4.5V
CC < 2.5V

CC ≤ 5.5V
CC < 4.5V
CC < 2.5V

4.5V ≤ VCC ≤ 5.5V

2.5V ≤ V

1.8V ≤ V

CC < 4.5V
CC < 2.5V

4.5V ≤ VCC ≤ 5.5V

2.5V ≤ V

1.8V ≤ V

4.5V ≤ V

2.5V ≤ V

1.8V ≤ V

4.5V ≤ V

2.5V ≤ V

1.8V ≤ V

CC < 4.5V
CC < 2.5V

CC ≤ 5.5V
CC < 4.5V
CC < 2.5V

CC ≤ 5.5V (Note 1)
CC ≤ 4.5V (Note 1)
CC ≤ 2.5V (Note 1)

4.5V ≤ VCC ≤ 5.5V

2.5V ≤ V

1.8V ≤ V

CC < 4.5V
CC < 2.5V

 2003 Microchip Technology Inc. DS21807B-page 3

25XX160A/B

TABLE 1-2: AC CHARACTERISTICS (CONTINUED)

Industrial (I): T
Automotive (E): T

Param.

No.

AC CHARACTERISTICS

Sym. Characteristic Min. Max. Units Test Conditions

17 THH HOLD Hold Time 20

40
80

18 T

HZ HOLD Low to Output

High-Z

30
60

160

19 T

HV HOLD High to Output

Val id

30
60

160

20 T

WC Internal Write Cycle Time — 5 ms (NOTE 3)

AMB = -40°C to +85°C VCC = 1.8V to 5.5V
AMB = -40°C to +125°C VCC = 2.5V to 5.5V

—
—
—

—
—
—

—
—
—

ns
ns
ns

ns
ns
ns

ns
ns
ns

21 — Endurance 1M — E/W

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.

WC begins on the rising edge of CS after a valid write sequence and ends when the internal write cycle is

3: T

complete.

4.5V ≤ VCC ≤ 5.5V

2.5V ≤ V

1.8V ≤ V

4.5V ≤ V

2.5V ≤ V

1.8V ≤ V

CC < 4.5V
CC < 2.5V

CC ≤ 5.5V (Note 1)
CC < 4.5V (Note 1)
CC < 2.5V (Note 1)

4.5V ≤ VCC ≤ 5.5V

2.5V ≤ V

1.8V ≤ V

(N

CC < 4.5V
CC < 2.5V

OTE 2)

TABLE 1-3: AC TEST CONDITIONS

AC Waveform:

LO = 0.2V —

V

HI = VCC - 0.2V (Note 1)

V

V

HI = 4.0V (Note 2)

Timing Measurement Reference Level

Input 0.5 V

Output 0.5 VCC

Note 1: For VCC ≤ 4.0V

2: For V

CC > 4.0V

CC

DS21807B-page 4  2003 Microchip Technology Inc.

FIGURE 1-1: HOLD TIMING

CS

SCK

SO

n+2 n+1 n n-1

16

17

18

high-impedance

16

25XX160A/B

17

19

n

SI

HOLD

n+2 n+1 n

FIGURE 1-2: SERIAL INPUT TIMING

CS

2

Mode 1,1

Mode 0,0

SCK

65

SI

SO

MSB in

high-impedance

don’t care

7

8

LSB in

5

n

3

n-1

4

12

11

FIGURE 1-3: SERIAL OUTPUT TIMING

CS

9

10

SCK

13

SO

SI

 2003 Microchip Technology Inc. DS21807B-page 5

MSB out

don’t care

14

3

Mode 1,1

Mode 0,0

15

ISB out

25XX160A/B

2.0 FUNCTIONAL DESCRIPTION

2.1 Principles of Operation

The 25XX160A/B are 2048 byte Serial EEPROMs
designed to interface directly with the Serial Peripheral
Interface (SPI) port of many of today’s popular
microcontroller families, including Microchip’s
PICmicro
microcontrollers that do not have a built-in SPI port by
using discrete I/O lines programmed properly with the
software.

The 25XX160A/B 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
be low and the HOLD
operation.

Table 2-1 contains a list of the possible instruction
bytes and format for device operation. All instructions,
addresses, and data are transferred MSB first, LSB
last.

Data (SI) is sampled on the first rising edge of SCK
after CS
peripheral devices on the SPI bus, the user can assert
the HOLD
mode. After releasing the HOLD
resume from the point when the HOLD

2.2 Read Sequence

The device is selected by pulling CS low. The 8-bit read
instruction is transmitted to the 25XX160A/B followed
by the 16-bit address, with the five 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 is 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 is shifted out. When the highest
address is reached (07FFh), 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

®

microcontrollers. It may also interface with

pin must

pin must be high for the entire

goes low. If the clock line is shared with other

input and place the 25XX160A/B in ‘HOLD’

pin, operation will

was asserted.

pin (Figure 2-1).

2.3 Write Sequence

Prior to any attempt to write data to the 25XX160A/B,
the write enable latch must be set by issuing the WREN
instruction (Figure 2-4). This is done by setting CS
and then clocking out the proper instruction into the
25XX160A/B. After all eight bits of the instruction are
transmitted, the CS
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.

Once the write enable latch is set, the user may
proceed by setting the CS
instruction, followed by the 16-bit address, with the five
MSBs of the address being don’t care bits, and then the
data to be written. Up to 16 bytes (25XX160A) or 32
bytes (25XX160B) 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.

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 wraps 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.

For the data to be actually written to the array, the CS
must be brought high after the Least Significant bit (D0)
of the n
brought high at any other time, the write operation will
not be completed. Refer to Figure 2-2 and Figure 2-3
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 2-6). 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.

th

data byte has been clocked in. If CS is

must be brought high to set the

low, issuing a WRITE

low

DS21807B-page 6  2003 Microchip Technology Inc.

Block Diagram

25XX160A/B

SO

CS

SCK

HOLD

WP

I/O Control

SI

Status

Register

Logic

Memory

Control

Logic

VCC
VSS

X

Dec

HV Generator

EEPROM

Array

Page Latches

Y Decoder

Sense Amp.
R/W Control

TABLE 2-1: INSTRUCTION SET

Instruction Name Instruction Format Description

READ

WRITE

WRDI
WREN
RDSR
WRSR

0000 0011
0000 0010
0000 0100
0000 0110
0000 0101
0000 0001

Read data from memory array beginning at selected address

Write data to memory array beginning at selected address

Reset the write enable latch (disable write operations)

Set the write enable latch (enable write operations)

Read Status Register

Write Status Register

FIGURE 2-1: READ SEQUENCE

CS

0 2 3 4 5 6 7 8 910 11 21222324252627282930311

SCK

instruction 16-bit address

SI

SO

 2003 Microchip Technology Inc. DS21807B-page 7

0100000 1 15 14 13 12 210

high-impedance

data out

76543210

25XX160A/B

FIGURE 2-2: BYTE WRITE SEQUENCE

CS

8

9 1011 2122232425262728293031

SCK

SI

SO

0 2345671

instruction 16-bit address data byte

0000000 1 15 14 13 12

high-impedance

FIGURE 2-3: PAGE WRITE SEQUENCE

CS

8

SCK

SI

CS

0 2345671

instruction 16-bit address data byte 1

0000000 1 15 14 13 12

Twc

21076543210

9 1011 2122232425262728293031

21076543210

SCK

SI

32 34 35 36 37 38 3933

data byte 2

76543210

41 42 43 46 47

40

data byte 3

76543210

44 45

data byte n (16/32 max)

76543210

DS21807B-page 8  2003 Microchip Technology Inc.