28C64A

Obsolete Device 28C64A 64K (8K x 8) CMOS EEPROM FEATURES Fast Read Access Time—150 ns CMOS Technology for Low Power Dissipation - 30 mA Active - 100 µA Standby Fast Byte Write Time—200 µs or 1 ms Data Retention >200 years High Endurance - Minimum 100,000 Erase/Write Cycles Automatic Write Operation - Internal Control Timer - Auto-Clear Before Write Operation - On-Chip Address and Data Latches Data Polling Ready/Busy Chip Clear Operation Enhanced Data Protection - VCC Detector - Pulse Filter - Write Inhibit Electronic Signature for Device Identification 5-Volt-Only Operation Organized 8Kx8 JEDEC Standard Pinout - 28-pin Dual-In-Line Package - 32-pin PLCC Package - 28-pin SOIC Package Available for Extended Temperature Ranges: - Commercial: 0°C to +70°C - Industrial: -40°C to +85°C DESCRIPTION The Microchip Technology Inc. 28C64A is a CMOS 64K nonvolatile electrically Erasable PROM. The 28C64A 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 control timer. To determine when the write cycle is complete, the user has a choice of monitoring the Ready/ Busy output or using Data polling. The Ready/Busy pin is an open drain ou...