1. Features
• Low-voltage and Standard-voltage Operation
–2.7(V
CC
=2.7Vto5.5V)
–1.8(V
CC
=1.8Vto5.5V)
• User-selectable Internal Organization
– 2K:256x8or128x16
– 4K:512x8or256x16
• Three-wire Serial Interface
• Sequential Read Operation
• 2 MHz Clock Rate (5V)
• Self-timed Write Cycle (10 ms Max)
• High Reliability
– Endurance: 1 Million Write Cycles
– Data Retention: 100 Years
• Automotive Devices Available
• 8-lead JEDEC PDIP, 8-lead JEDEC SOIC, 8-lead EIAJ SOIC, 8-lead Ultra Thin mini-MAP
(MLP 2x3), 8-lead Ultra Lead Frame Land Grid Array (ULA), 8-lead TSSOP and 8-ball
dBGA2 Packages
2. Description
The AT93C56A/66A provides 2048/4096 bits of serial electrically erasable program-
mable read-only memory (EEPROM) organized as 128/256 words of 16 bits each
(when the ORG pin is connected to VCC) and 256/512 words of 8 bits each (when the
ORG pin is tied to ground). The device is optimized for use in many industrial and
commercial applications where low-power and low-voltage operations are essential.
The AT93C56A/66A is available in space-saving 8-lead PDIP, 8-lead JEDEC SOIC, 8-
lead EIAJ SOIC, 8-lead Ultra Thin mini-MAP (MLP 2x3), 8-lead Ultra Lead Frame Land
Grid Array (ULA), 8-lead TSSOP, and 8-ball dBGA2 packages.
The AT93C56A/66A is enabled through the Chip Select pin (CS) and accessed via a
three-wire serial interface consisting of Data Input (DI), Data Output (DO), and Shift
Clock (SK). Upon receiving a read instruction at DI, the address is decoded and the
data is clocked out serially on the data output pin DO. The write cycle is completely
self-timed and no separate erase cycle is required before write. The write cycle is only
enabled when the part is in the Erase/Write Enable State. When CS is brought “high”
following the initiation of a write cycle, the DO pin outputs the Ready/Busy status of
the part.
The AT93C56A/66A is available in 2.7V to 5.5V and 1.8V to 5.5V versions.
Three-wire
Serial
EEPROM
2K (256 x 8 or 128 x 16)
4K (512 x 8 or 256 x 16)
AT93C56A
AT93C66A
Not Recommended
for New Design.
Replaced by
AT93C56B or
AT93C66B.
3378O–SEEPR–11/09
