AS6VA25616

The AS6VA25616 is a low-power CMOS 4,194,304-bit Static Random Access Memory (SRAM) device organized as 262,144 words * 16 bits. It is designed for memory applications where slow data access, low power, and simple interfacing are desired.

Equal address access and cycle times (tAA, tRC, tWC) of 55 ns are ideal for low-power applications. Active high and low chip selects (CS) permit easy memory expansion with multiple-bank memory systems.

When CS is high, or UB and LB are high, the device enters standby mode: the AS6VA25616 is guaranteed not to exceed 66 W power consumption at 3.3V and 55 ns. The device also returns data when VCC is reduced to 1.5V for even lower power consumption.

A write cycle is accomplished by asserting write enable (WE) and chip select (CS) low, and UB and/or LB low. Data on the input pins I/O1O16 is written on the rising edge of WE (write cycle 1) or CS (write cycle 2). To avoid bus contention, external devices should drive I/O pins only after outputs have been disabled with output enable (OE) or write enable (WE).

A read cycle is accomplished by asserting output enable (OE), chip select (CS), UB and LB low, with write enable (WE) high. The chip drives I/O pins with the data word referenced by the input address. When either chip select or output enable is inactive, or write enable is active, or (UB) and (LB), output drivers stay in high-impedance mode.

These devices provide multiple center power and ground pins, and separate byte enable controls, allowing individual bytes to be written and read. LB controls the lower bits, I/O1I/O8, and UB controls the higher bits, I/O9I/O16.

All chip inputs and outputs are CMOS-compatible, and operation is from a single 2.7V to 3.3V supply. Device is available in the JEDEC standard 400-mm, TSOP II, and 48-ball FBGA packages.