Cypress CY62148BN manual Features, Functional Description, Logic Block Diagram, A a a a

CY62148BN MoBL®

4-Mbit (512K x 8) Static RAM

Features

•High Speed

—70 ns

•4.5V–5.5V operation

•Low active power

—Typical active current: 2.5 mA @ f = 1 MHz

—Typical active current:12.5 mA @ f = fmax(70 ns)

•Low standby current

•Automatic power-down when deselected

•TTL-compatible inputs and outputs

•Easy memory expansion with CE and OE features

•CMOS for optimum speed/power

•Available in standard lead-free and non-lead-free 32-lead (450-mil) SOIC, 32-lead TSOP II and 32-lead Reverse TSOP II packages

Functional Description

The CY62148BN is a high-performance CMOS static RAM organized as 512K words by 8 bits. Easy memory expansion is provided by an active LOW Chip Enable (CE), an active LOW Output Enable (OE), and three-state drivers. This device has an automatic power-down feature that reduces power consumption by more than 99% when deselected.

Writing to the device is accomplished by taking Chip Enable (CE) and Write Enable (WE) inputs LOW. Data on the eight I/O pins (I/O0 through I/O7) is then written into the location specified on the address pins (A0 through A18).

Reading from the device is accomplished by taking Chip Enable (CE) and Output Enable (OE) LOW while forcing Write Enable (WE) HIGH for read. Under these conditions, the contents of the memory location specified by the address pins will appear on the I/O pins.

The eight input/output pins (I/O0 through I/O7) are placed in a high-impedance state when the device is deselected (CE HIGH), the outputs are disabled (OE HIGH), or during a write operation (CE LOW, and WE LOW).

Logic Block Diagram
		INPUT BUFFER					I/O0
A0							I/O1
A1	DECODER						I/O2
A4
A5					AMPS
A6			512K x 8				I/O3
A7
A	ROW		ARRAY		SENSE
A12							I/O4
14
A16
A17							I/O5
			COLUMN		POWER		I/O6
CE					DOWN
			DECODER
							I/O7
WE
		2 3		9
OE			15 18 13 8 A 11 10
		A A A A A A		A A
Cypress Semiconductor Corporation		•	198 Champion Court			•	San Jose, CA 95134-1709	•	408-943-2600
Document #: 001-06517 Rev. *A							Revised August 2, 2006

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