28C04A
4K (512 x 8) CMOS EEPROM
FEATURES
PACKAGE TYPES
• Fast Read Access Time—150 ns
• CMOS Technology for Low Power Dissipation
- 30 mA Active
DIP
A7
A6
• 1
2
24 Vcc
23 A8
22 NC
21 WE
20 OE
19 NC
18 CE
17 I/O7
16 I/O6
15 I/O5
14
A5
3
A4
4
A3
5
- 100 µA Standby
A2
6
• Fast Byte Write Time—200 µs or 1 ms
• Data Retention >200 years
A1
7
A0
8
I/O0
I/O1
I/O2
9
4
• Endurance - Minimum 10 Erase/Write Cycles
10
11
- Automatic Write Operation
- Internal Control Timer
I/O4
VSS 12
13 I/O3
- Auto-Clear Before Write Operation
- On-Chip Address and Data Latches
• Data Polling
PLCC
• Chip Clear Operation
A6
5
6
7
8
9
29 A8
A5
A4
A3
A2
A1 10
A0 11
28 NC
27 NC
26 NC
25 OE
24 NC
23 CE
22 I/O7
21 I/O6
• Enhanced Data Protection
- VCC Detector
- Pulse Filter
- Write Inhibit
NC 12
I/O0 13
• 5-Volt-Only Operation
• Organized 512x8 JEDEC standard pinout
- 24-pin Dual-In-Line Package
- 32-pin PLCC Package
• Pin 1 indicator on PLCC on top of package
• Available for Extended Temperature Ranges:
- Commercial: 0˚C to +70˚C
- Industrial: -40˚C to +85˚C
BLOCK DIAGRAM
I/O0
I/O7
DESCRIPTION
VSS
Data Protection
The Microchip Technology Inc. 28C04A is a CMOS 4K
non-volatile electrically Erasable and Programmable
Read Only Memory (EEPROM). The 28C04A is
accessed like a static RAM for the read or write cycles
without the need of external components. During a
“byte write”, the address and data are latched internally,
freeing the microprocessor address and data bus for
other operations. Following the initiation of write cycle,
the device will go to a busy state and automatically
clear and write the latched data using an internal con-
trol timer. To determine when a write cycle is complete,
the 28C04A uses Data polling. Data polling allows the
user to read the location last written to when the write
operation is complete. CMOS design and processing
enables this part to be used in systems where reduced
power consumption and reliability are required. A com-
plete family of packages is offered to provide the utmost
flexibility in applications.
VCC
Circuitry
Chip Enable/
Output Enable
Control Logic
CE
OE
Input/Output
Buffers
WE
Auto Erase/Write
Timing
Data
Poll
Program Voltage
Generation
A0
Y
Y Gating
Decoder
L
a
t
c
h
e
s
4K bit
Cell Matrix
X
Decoder
A8
1996 Microchip Technology Inc.
DS11126F-page 1
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