25C320
32K 5.0V SPI Bus Serial EEPROM
FEATURES
PACKAGE TYPES
DIP/SOIC
• SPI modes 0,0 and 1,1
• 3.0 MHz Clock Rate
• Single 5V Supply
CS
SO
1
2
3
4
8
7
6
5
VCC
• Low Power CMOS Technology
- Max Write Current: 5 mA
- Read Current: 1.0 mA at 5.5V, 3MHz
- Standby Current: 1 µA typical
• 4096 x 8 Organization
HOLD
WP
VSS
SCK
SI
• 32 Byte Page
• Sequential Read
• 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
TSSOP
CS 1
SO 2
NC 3
NC 4
NC 5
WP 6
VSS7
14 VCC
13 HOLD
12 NC
11 NC
10 NC
9 SCK
8 SI
- Write Protect Pin
• High Reliability
BLOCK DIAGRAM
- Endurance: 1M cycles (guaranteed)
- Data Retention: >200 years
- ESD protection: >4000V
• 8-pin PDIP/SOIC, 14-pin TSSOP
• Temperature ranges supported
Status
Register
HV Generator
- Commercial (C):
- Industrial (I):
- Automotive (E):
0°C to +70°C
-40°C to +85°C
-40°C to +125°C
EEPROM
Array
Memory
Control
Logic
X
I/O Control
Logic
DESCRIPTION
Dec
The Microchip Technology Inc. 25C320 is a 32K-bit
serial Electrically Erasable PROM (EEPROM). 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, allowing any
number of devices to share the same bus.
Page Latches
Y Decoder
WP
SI
SO
CS
SCK
HOLD
Sense Amp.
R/W Control
There are two other inputs that provide the end user
with additional flexibility. 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. Also write
operations to the Status Register can be disabled via
the write protect pin (WP).
Vcc
Vss
SPI is a trademark of Motorola.
1996 Microchip Technology Inc.
Preliminary
DS21159B-page 1
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