Preliminary Information
CAT1024, CAT1025
Supervisory Circuits with I
2
C Serial 2k-bit CMOS EEPROM and Manual Reset
FEATURES
s
Precision power supply voltage monitor
s
16-Byte page write buffer
H
GEN
FR
ALO
EE
LE
A
D
F
R
E
E
TM
s
Built-in inadvertent write protection
— 5V, 3.3V and 3V systems
— Five threshold voltage options
s
Active high or low reset
— WP pin (CAT1025)
s
1,000,000 Program/Erase cycles
s
Manual reset input
s
100 year data retention
s
8-pin DIP, SOIC, TSSOP, MSOP & TDFN
— Valid reset guaranteed at V
CC
= 1V
s
400kHz I
2
C bus
s
2.7V to 5.5V operation
s
Low power CMOS technology
(3x4.9mm & 3x3mm foot print) packages
s
Industrial and extended temperature ranges
DESCRIPTION
The CAT1024 and CAT1025 are complete memory and
supervisory solutions for microcontroller-based systems.
A 2k-bit serial EEPROM memory and a system power
supervisor with brown-out protection are integrated
together in low power CMOS technology. Memory
interface is via a 400kHz I
2
C bus.
The CAT1025 provides a precision V
CC
sense circuit
and two open drain outputs: one (RESET) drives high
and the other (RESET) drives low whenever V
CC
falls
below the reset threshold voltage. The CAT1025 also
has a Write Protect input (WP). Write operations are
disabled if WP is connected to a logic high.
The CAT1024 also provides a precision V
CC
sense
circuit, but has only a
RESET
output and does not have
a Write Protect input.
The power supply monitor and reset circuit protect
memory and system controllers during power up/down
and against brownout conditions. Five reset threshold
voltages support 5V, 3.3V and 3V systems. If power supply
voltages are out of tolerance reset signals become active,
preventing the system microcontroller, ASIC or peripherals
from operating. Reset signals become inactive typically 200
ms after the supply voltage exceeds the reset threshold
level. With both active high and low reset signals, interface
to microcontrollers and other ICs is simple. In addition, the
RESET
pin or a separate input,
MR,
can be used as an input
for push-button manual reset capability.
The CAT1024/25 memory features a 16-byte page. In
addition, hardware data protection is provided by a V
CC
sense circuit that prevents writes to memory whenever V
CC
falls below the reset threshold or until V
CC
reaches the reset
threshold during power up.
Available packages include an 8-pin DIP and a surface
mount 8-pin SO, 8-pin TSSOP, 8-pin TDFN and 8-pin MSOP
packages. The TDFN package thickness is 0.8mm maximum.
TDFN footprint options are 3x3mm or 3x4.9mm (MSOP pad
layout).
PIN CONFIGURATION
DIP Package (P, L)
SOIC Package (S, V)
TSSOP Package (U, Y)
MSOP Package (R, Z)
MR
1
RESET
2
NC 3
VSS 4
CAT1024
8 VCC
7 NC
6 SCL
5 SDA
(Bottom View)
(Bottom View)
TDFN Package: 3mm x 3mm
TDFN Package: 3mm x 4.9mm
0.8mm maximum height - (RD2, ZD2) 0.8mm maximum height - (RD4, ZD4)
VCC
NC
SCL
SDA
8
7
1
2
MR
RESET
NC
VSS
VCC
NC
SCL
SDA
8
7
1
2
MR
RESET
NC
VSS
CAT1024
6
5
CAT1024
6
5
3
4
3
4
MR
1
RESET
2
RESET 3
VSS 4
CAT1025
8 VCC
7 WP
6 SCL
5 SDA
VCC
WP
SCL
SDA
8
7
1
2
MR
RESET
RESET
VSS
VCC
8
WP
7
SCL
6
SDA
5
1
MR
2
RESET
CAT1025
6
5
3
4
CAT1025
3
RESET
4
V
SS
© 2003 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
Doc No. 3008, Rev. I
CAT1024, CAT1025
Preliminary Information
BLOCK DIAGRAM — CAT1024, CAT1025
EXTERNAL LOAD
DOUT
ACK
VCC
VSS
WORD ADDRESS
BUFFERS
COLUMN
DECODERS
SENSE AMPS
SHIFT REGISTERS
Threshold Voltage Options
Part Dash Minimum
Number Threshold
-45
-42
-30
-28
4.50
4.25
3.00
2.85
2.55
Maximum
Threshold
4.75
4.50
3.15
3.00
2.70
SDA
START/STOP
LOGIC
2kbit
EEPROM
-25
XDEC
WP*
CONTROL
LOGIC
DATA IN STORAGE
HIGH VOLTAGE/
TIMING CONTROL
RESET Controller
Precision
MR
Vcc Monitor
STATE COUNTERS
SLAVE
ADDRESS
COMPARATORS
SCL
*
RESET
*CAT1025 Only
RESET
PIN FUNCTIONS
Pin Name
NC
RESET
V
SS
SDA
SCL
RESET
V
CC
WP
MR
OPERATING TEMPERATURE RANGE
Industrial
Extended
-40˚C to 85˚C
-40˚C to 125˚C
Function
No Connect
Active Low Reset Input/Output
Ground
Serial Data/Address
Clock Input
Active High Reset Output (CAT1025 only)
Power Supply
Write Protect (CAT1025 only)
Manual Reset Input
Doc. No. 3008, Rev. I
2
Preliminary Information
CAT1024, CAT1025
PIN DESCRIPTION
RESET/RESET
RESET:
RESET OUTPUTS
RESET
(RESET CAT1025 Only)
These are open drain pins and
RESET
can be used as a
manual reset trigger input. By forcing a reset condition on
the pin the device will initiate and maintain a reset condition.
The RESET pin must be connected through a pull-down
resistor, and the
RESET
pin must be connected through a
pull-up resistor.
SDA:
SERIAL DATA ADDRESS
The bidirectional serial data/address pin is used to transfer
all data into and out of the device. The SDA pin is an open
drain output and can be wire-ORed with other open drain
or open collector outputs.
SCL:
SERIAL CLOCK
Serial clock input.
MANUAL RESET INPUT
MR:
Manual Reset input is a debounced input that can be
connected to an external source for Manual Reset.
Pulling the MR input low will generate a Reset condition.
Reset outputs are active while
MR
input is low and for
the reset timeout period after
MR
returns to high. The
input has an internal pull-up resistor.
WP (CAT1025 Only):
WRITE PROTECT INPUT
When tied to V
SS
or left unconnected write operations
to the entire array are allowed. When tied to V
CC
, the
entire array is protected. This input has an internal pull
down resistor.
CAT10XX FAMILY OVERVIEW
Device
Manual
Reset
Input Pin
Watchdog
Watchdog
Monitor
Pin
SDA
SDA
WDI
Write
Protection
Pin
Independent
Auxiliary
Voltage Sense
RESET: Active
High and LOW
EEPROM
CAT1021
CAT1022
CAT1023
CAT1024
CAT1025
CAT1026
CAT1027
2k
2k
2k
2k
2k
2k
WDI
2k
For supervisory circuits with embedded 16k EEPROM, please refer to the CAT1161, CAT1162 and CAT1163
data sheets.
3
Doc No. 3008, Rev. I
CAT1024, CAT1025
Preliminary Information
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 specification
is not implied. Exposure to any absolute maximum rating for extended
periods may affect device performance and reliability.
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.
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 Ground
(1)
............ –2.0V to +V
CC
+2.0V
V
CC
with Respect to Ground ............... –2.0V to +7.0V
Package Power Dissipation
Capability (T
A
= 25°C) ................................... 1.0W
Lead Soldering Temperature (10 secs) ............ 300°C
Output Short Circuit Current
(2)
........................ 100 mA
D.C. OPERATING CHARACTERISTICS
V
CC
= +2.7V to +5.5V and over the recommended temperature conditions unless otherwise specified.
Symbol
I
LI
I
LO
I
CC1
I
CC2
I
SB
V
IL(1)
V
IH(1)
V
OL
V
OH
Parameter
Input Leakage Current
Output Leakage Current
Power Supply Current (Write)
Power Supply Current (Read)
Standby Current
Input Low Voltage
Input High Voltage
Output Low Voltage
(SDA,
RESET
)
Output High Voltage
(RESET)
I
OL
= 3mA
V
CC
= 2.7V
I
OH
= -0.4mA
V
CC
= 2.7V
CAT102x-45
(V
CC
= 5V)
CAT102x-42
(V
CC
= 5V)
V
TH
Reset Threshold
CAT102x-30
(V
CC
= 3.3V)
CAT102x-28
(V
CC
= 3.3V)
CAT102x-25
(V
CC
= 3V)
V
RVALID
V
RT(2)
Reset Output Valid V
CC
Voltage
Reset Threshold Hysteresis
Vcc -
0.75
4.50
4.25
3.00
2.85
2.55
1.00
15
4.75
4.50
3.15
3.00
2.70
V
mV
V
Test Conditions
V
IN
= GND to Vcc
V
IN
= GND to Vcc
f
SCL
= 400kHz
V
CC
= 5.5V
f
SCL
= 400kHz
V
CC
= 5.5V
Vcc = 5.5V,
V
IN
= GND or Vcc
-0.5
0.7 x Vcc
Min
-2
-10
Typ
Max
10
10
3
1
40
0.3 x Vcc
Vcc + 0.5
0.4
Units
µA
µA
mA
mA
µA
V
V
V
V
Notes:
1. V
IL
min and V
IH
max are reference values only and are not tested.
2. This parameter is tested initially and after a design or process change that affects the parameter. Not 100% tested.
Doc. No. 3008, Rev. I
4
Preliminary Information
CAT1024, CAT1025
CAPACITANCE
T
A
= 25°C, f = 1.0 MHz, V
CC
= 5V
Symbol
C
OUT(1)
C
IN(1)
Test
Output Capacitance
Input Capacitance
Test Conditions
V
OUT
= 0V
V
IN
= 0V
Max
8
6
Units
pF
pF
AC CHARACTERISTICS
V
CC
= 2.7V to 5.5V and over the recommended temperature conditions, unless otherwise specified.
Memory Read & Write Cycle
2
Symbol
f
SCL
t
SP
t
LOW
t
HIGH
t
R(1)
t
F(1)
t
HD;STA
t
SU;STA
t
HD;DAT
t
SU;DAT
t
SU;STO
t
AA
t
DH
t
BUF(1)
t
WC(3)
Parameter
Clock Frequency
Input Filter Spike
Suppression (SDA, SCL)
Clock Low Period
Clock High Period
SDA and SCL Rise Time
SDA and SCL Fall Time
Start Condition Hold Time
Start Condition Setup Time
(for a Repeated Start)
Data Input Hold Time
Data Input Setup Time
Stop Condition Setup Time
SCL Low to Data Out Valid
Data Out Hold Time
Time the Bus must be Free Before a
New Transmission Can Start
Write Cycle Time (Byte or Page)
50
1.3
5
0.6
0.6
0
100
0.6
900
1.3
0.6
300
300
Mi n
Max
400
100
Units
kHz
ns
µs
µs
ns
ns
µs
µs
ns
ns
µs
ns
ns
µs
ms
Notes:
1. This parameter is characterized initially and after a design or process change that affects the parameter. Not 100% tested.
2. Test Conditions according to “AC Test Conditions” table.
3. The write cycle time is the time from a valid stop condition of a write sequence to the end of the internal program/erase cycle. During the write
cycle, the bus interface circuits are disabled, SDA is allowed to remain high and the device does not respond to its slave address.
5
Doc No. 3008, Rev. I
嵌入式系统
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