CAT25C128/256
128K/256K-Bit SPI Serial CMOS E
2
PROM
FEATURES
s
5 MHz SPI Compatible
s
1.8 to 6.0 Volt Operation
s
Hardware and Software Protection
s
Zero Standby Current
s
Low Power CMOS Technology
s
SPI Modes (0,0 &1,1)
s
Commercial, Industrial and Automotive
s
100,000 Program/Erase Cycles
s
100 Year Data Retention
s
Self-Timed Write Cycle
s
8-Pin DIP/SOIC, 16-Pin SOIC, 14-Pin TSSOP
and 20-Pin TSSOP
s
64-Byte Page Write Buffer
s
Block Write Protection
Temperature Ranges
– Protect 1/4, 1/2 or all of E
2
PROM Array
DESCRIPTION
The CAT25C128/256 is a 128K/256K-Bit SPI Serial
CMOS E
2
PROM internally organized as 16Kx8/32Kx8
bits. Catalyst’s advanced CMOS Technology substan-
tially reduces device power requirements. The
CAT25C128/256 features a 64-byte page write buffer.
The device operates via the SPI bus serial interface and
is enabled though a Chip Select (CS). In addition to the
Chip Select, the clock input (SCK), data in (SI) and data
out (SO) are required to access the device. The
HOLD
pin may be used to suspend any serial communication
without resetting the serial sequence. The CAT25C128/
256 is designed with software and hardware write pro-
tection features including Block Lock protection. The
device is available in 8-pin DIP, 8-pin SOIC, 16-pin
SOIC, 14-pin TSSOP and 20-pin TSSOP packages.
PIN CONFIGURATION
SOIC Package (S, K) TSSOP Package (U14)
CS
SO
WP
VSS
1
2
3
4
8
7
6
5
VCC
HOLD
SCK
SI
BLOCK DIAGRAM
DIP Package (P)
CS
SO
WP
VSS
1
2
3
4
8
7
6
5
VCC
HOLD
SCK
SI
SENSE AMPS
SHIFT REGISTERS
SOIC Package (S16)
CS
SO
NC
NC
NC
NC
WP
V
SS
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VCC
HOLD
NC
NC
NC
NC
SCK
SI
CS
SO
NC
NC
NC
WP
V
SS
1
2
3
4
5
6
7
14
13
12
11
10
9
8
VCC
HOLD
NC
NC
NC
SCK
SI
WORD ADDRESS
BUFFERS
COLUMN
DECODERS
TSSOP Package (U20)
NC
CS
SO
SO
NC
NC
WP
V
SS
NC
NC
PIN FUNCTIONS
Pin Name
SO
SCK
WP
V
CC
V
SS
CS
SI
HOLD
NC
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
NC
VCC
HOLD
HOLD
NC
NC
SCK
SI
NC
NC
SO
SI
CS
WP
HOLD
SCK
I/O
CONTROL
SPI
CONTROL
LOGIC
BLOCK
PROTECT
LOGIC
CONTROL LOGIC
XDEC
E
2
PROM
ARRAY
Function
Serial Data Output
Serial Clock
Write Protect
+1.8V to +6.0V Power Supply
Ground
Chip Select
Serial Data Input
Suspends Serial Input
No Connect
STATUS
REGISTER
DATA IN
STORAGE
HIGH VOLTAGE/
TIMING CONTROL
25C128 F02
Note: CAT25C256 not available in 8-Lead S or U packages.
Doc. No. 25088-00 1/01
© 2001 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
CAT25C128/256
ABSOLUTE MAXIMUM RATINGS*
Temperature Under Bias ................. –55°C to +125°C
Storage Temperature ....................... –65°C to +150°C
Voltage on any Pin with
Respect to V
SS(1)
.................. –2.0V to +V
CC
+2.0V
V
CC
with Respect to V
SS ................................
–2.0V to +7.0V
Package Power Dissipation
Capability (Ta = 25°C) ................................... 1.0W
Lead Soldering Temperature (10 secs) ............ 300°C
Output Short Circuit Current
(2)
........................ 100 mA
RELIABILITY CHARACTERISTICS
Symbol
N
END(3)
T
DR(3)
V
ZAP(3)
I
LTH(3)(4)
Parameter
Endurance
Data Retention
ESD Susceptibility
Latch-Up
Min.
100,000
100
2000
100
Max.
*COMMENT
Stresses above those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device.
These are stress ratings only, and functional operation
of the device at these or any other conditions outside of
those listed in the operational sections of this specifica-
tion is not implied. Exposure to any absolute maximum
rating for extended periods may affect device perfor-
mance and reliability.
Units
Cycles/Byte
Years
Volts
mA
Reference Test Method
MIL-STD-883, Test Method 1033
MIL-STD-883, Test Method 1008
MIL-STD-883, Test Method 3015
JEDEC Standard 17
D.C. OPERATING CHARACTERISTICS
V
CC
= +1.8V to +6.0V, unless otherwise specified.
Limits
Symbol
I
CC1
I
CC2
I
SB
I
LI
I
LO
V
IL(3)
V
IH(3)
V
OL1
V
OH1
V
OL2
V
OH2
Parameter
Power Supply Current
(Operating Write)
Power Supply Current
(Operating Read)
Power Supply Current
(Standby)
Input Leakage Current
Output Leakage Current
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
Output Low Voltage
Output High Voltage
V
CC
-0.2
V
CC
- 0.8
0.2
-1
V
CC
x 0.7
Min.
Typ.
Max.
10
2
0
2
3
V
CC
x 0.3
V
CC
+ 0.5
0.4
Units
mA
mA
µA
µA
µA
V
V
V
V
V
V
4.5V≤V
CC
<5.5V
I
OL
= 3.0mA
I
OH
= -1.6mA
1.8V≤V
CC
<2.7V
I
OL
= 150µA
I
OH
= -100µA
V
OUT
= 0V to V
CC
,
CS = 0V
Test Conditions
V
CC
= 5V @ 5MHz
SO=open; CS=Vss
V
CC
= 5.5V
F
CLK
= 5MHz
CS
= V
CC
V
IN
= V
SS
or V
CC
Note:
(1) The minimum DC input voltage is –0.5V. During transitions, inputs may undershoot to –2.0V for periods of less than 20 ns. Maximum DC
voltage on output pins is V
CC
+0.5V, which may overshoot to V
CC
+2.0V for periods of less than 20 ns.
(2) Output shorted for no more than one second. No more than one output shorted at a time.
(3) This parameter is tested initially and after a design or process change that affects the parameter.
(4) Latch-up protection is provided for stresses up to 100 mA on address and data pins from –1V to V
CC
+1V.
Doc. No. 25088-00 1/01
2
CAT25C128/256
Figure 1. Sychronous Data Timing
V
IH
t
CS
CS
V
IL
t
CSS
V
IH
t
CSH
SCK
V
IL
t
SU
V
IH
t
WH
t
H
t
WL
SI
VIL
VALID IN
t
RI
tFI
t
V
V
OH
t
HO
t
DIS
HI-Z
SO
V
OL
HI-Z
Note: Dashed Line= mode (1, 1) — — — —
A.C. CHARACTERISTICS (CAT25C128)
Limits
Vcc=
1.8V-6.0V
SYMBOL
t
SU
t
H
t
WH
t
WL
f
SCK
t
LZ
t
RI(1)
t
FI(1)
t
HD
t
CD
t
WC
t
V
t
HO
t
DIS
t
HZ
t
CS
t
CSS
t
CSH
t
WPS
t
WPH
PARAMETER
Data Setup Time
Data Hold Time
SCK High Time
SCK Low Time
Clock Frequency
HOLD
to Output Low Z
Input Rise Time
Input Fall Time
HOLD
Setup Time
HOLD
Hold Time
Write Cycle Time
Output Valid from Clock Low
Output Hold Time
Output Disable Time
HOLD
to Output High Z
CS
High Time
CS
Setup Time
CS
Hold Time
WP Setup Time
WP Hold Time
1000
1000
1000
50
50
0
250
150
250
250
250
50
50
250
250
10
250
0
250
150
100
100
100
50
50
Min.
100
100
250
250
DC
1
50
2
2
250
250
10
250
0
100
50
Max.
V
CC
=
2.5V-6.0V
Min.
70
70
150
150
DC
3
50
2
2
40
40
5
80
Max.
V
CC
=
4.5V-5.5V
Min.
35
35
80
80
DC
5
50
2
2
Max.
UNITS
ns
ns
ns
ns
MHz
ns
µs
µs
ns
ns
ms
ns
ns
ns
ns
ns
ns
ns
ns
ns
Test
Conditions
C
L
= 50pF
NOTE:
(1) This parameter is tested initially and after a design or process change that affects the parameter.
3
Doc. No. 25088-00 1/01
CAT25C128/256
A.C. CHARACTERISTICS (CAT25C256)
Limits
Vcc=
1.8V-6.0V
SYMBOL PARAMETER
t
SU
t
H
t
WH
t
WL
f
SCK
t
LZ
t
RI(1)
t
FI(1)
t
HD
t
CD
t
WC
t
V
t
HO
t
DIS
t
HZ
t
CS
t
CSS
t
CSH
t
WPS
t
WPH
NOTE:
(1) This parameter is tested initially and after a design or process change that affects the parameter.
V
CC
=
2.5V-6.0V
100
100
250
250
Min. Max. Min.
500
500
2500
2500
DC
0.2
100
2
2
250
250
10
250
0
250
150
100
100
100
50
50
100
100
100
50
50
0
100
100
Test
Max. Min. Max. Min. Max. UNITS
Conditions
V
CC
=
2.7V-6.0V
70
70
V
CC
=
4.5V-5.5V
35
35
80
80
Data Setup Time
Data Hold Time
SCK High Time
SCK Low Time
Clock Frequency
HOLD
to Output Low Z
Input Rise Time
Input Fall Time
HOLD
Setup Time
HOLD
Hold Time
Write Cycle Time
Output Valid from Clock Low
Output Hold Time
Output Disable Time
HOLD
to Output High Z
CS
High Time
CS
Setup Time
CS
Hold Time
WP
Setup Time
WP
Hold Time
ns
ns
ns
ns
5
50
2
2
MHz
ns
µs
µs
ns
ns
5
80
ms
ns
ns
100
50
ns
ns
ns
ns
ns
ns
ns
C
L
= 50pF
200
200
2.0
50
2
2
100
100
10
200
0
200
100
100
100
100
50
50
200
100
10
200
DC
2.5
50
2
2
DC
DC
40
40
0
100
100
100
50
50
Doc. No. 25088-00 1/01
4
CAT25C128/256
FUNCTIONAL DESCRIPTION
The CAT25C128/256 supports the SPI bus data trans-
mission protocol. The synchronous Serial Peripheral
Interface (SPI) helps the CAT25C128/256 to interface
directly with many of today’s popular microcontrollers.
The CAT25C128/256 contains an 8-bit instruction regis-
ter. (The instruction set and the operation codes are
detailed in the instruction set table)
After the device is selected with
CS
going low, the first
byte will be received. The part is accessed via the SI pin,
with data being clocked in on the rising edge of SCK.
The first byte contains one of the six op-codes that define
the operation to be performed.
CS:
CS
Chip Select
CS
is the Chip select pin.
CS
low enables the CAT25C128/
256 and
CS
high disables the CAT25C128/256.
CS
high
takes the SO output pin to high impedance and forces
the device into a Standby Mode (unless an internal write
operation is underway) The CAT25C128/256 draws
ZERO current in the Standby mode. A high to low
transition on
CS
is required prior to any sequence being
initiated. A low to high transition on
CS
after a valid write
sequence is what initiates an internal write cycle.
WP:
WP
Write Protect
WP
is the Write Protect pin. The Write Protect pin will
allow normal read/write operations when held high.
When
WP
is tied low and the WPEN bit in the status
register is set to “1”, all write operations to the status
register are inhibited.
WP
going low while
CS
is still low
will interrupt a write to the status register. If the internal
write cycle has already been initiated,
WP
going low will
have no effect on any write operation to the status
register. The
WP
pin function is blocked when the WPEN
bit is set to 0.
HOLD:
HOLD
Hold
HOLD
is the HOLD pin. The
HOLD
pin is used to pause
transmission to the CAT25C128/256 while in the middle
of a serial sequence without having to re-transmit entire
sequence at a later time. To pause,
HOLD
must be
brought low while SCK is low. The SO pin is in a high
impedance state during the time the part is paused, and
transitions on the SI pins will be ignored. To resume
communication,
HOLD
is brought high, while SCK is low.
(HOLD
should be held high any time this function is not
being used.)
HOLD
may be tied high directly to V
cc
or tied
to V
cc
through a resistor. Figure 9 illustrates hold timing
sequence.
PIN DESCRIPTION
SI: Serial Input
SI is the serial data input pin. This pin is used to input all
opcodes, byte addresses, and data to be written to the
25C128/256. Input data is latched on the rising edge of
the serial clock.
SO: Serial Output
SO is the serial data output pin. This pin is used to
transfer data out of the 25C128/256. During a read cycle,
data is shifted out on the falling edge of the serial clock.
SCK: Serial Clock
SCK is the serial clock pin. This pin is used to synchro-
nize the communication between the microcontroller
and the 25C128/256. Opcodes, byte addresses, or data
present on the SI pin are latched on the rising edge of the
SCK. Data on the SO pin is updated on the falling edge
of the SCK.
INSTRUCTION SET
Instruction
WREN
WRDI
RDSR
WRSR
READ
WRITE
Opcode
0000 0110
0000 0100
0000 0101
0000 0001
0000 0011
0000 0010
Operation
Enable Write Operations
Disable Write Operations
Read Status Register
Write Status Register
Read Data from Memory
Write Data to Memory
5
Doc. No. 25088-00 1/01