CY62256

256K (32K x 8) Static RAM

Features

• High speed

  — 55 ns

• Temperature Ranges

  — Commercial: 0°C to 70°C

  — Industrial: –40°C to 85°C

  — Automotive: –40°C to 125°C

• Voltage range

  — 4.5V – 5.5V

• Low active power and standby power

• Easy memory expansion with CE and OE features

• TTL-compatible inputs and outputs

• Automatic power-down when deselected

• CMOS for optimum speed/power

• Available in a Pb-free and non Pb-free standard 28-pin narrow SOIC, 28-pin TSOP-1,

  28-pin Reverse TSOP-1 and 28-pin DIP packages

Functional Description 

The CY62256 is a high-performance CMOS static RAM organized as 32K words by 8 bits. Easy memory expansion is provided by an active LOW chip enable (CE) and active LOW output enable (OE) and Tri-state drivers. This device has an automatic power-down feature, reducing the power consumption by 99.9% when deselected.

An active LOW write enable signal (WE) controls the writing/reading operation of the memory. When CE and WE inputs are both LOW, data on the eight data input/output pins (I/O0 through I/O7) is written into the memory location addressed by the address present on the address pins (A0 through A14). Reading the device is accomplished by selecting the device and enabling the outputs, CE and OE active LOW, while WE remains inactive or HIGH. Under these conditions, the contents of the location addressed by the information on address pins are present on the eight data input/output pins. The input/output pins remain in a high-impedance state unless the chip is selected, outputs are enabled, and write enable (WE) is HIGH.

Logic Block Diagram

Pin Configurations

Maximum Ratings

(Above which the useful life may be impaired. For user guidelines, not tested.)

Storage Temperature .................................–65°C to +150°C

Ambient Temperature with

Power Applied.............................................–55°C to +125°C

Supply Voltage to Ground Potential

(Pin 28 to Pin 14) .............................................. –0.5V to +7V

DC Voltage Applied to Outputs

in High-Z State  .................................... –0.5V to V_CC + 0.5V

DC Input Voltage  ................................  –0.5V to V_CC + 0.5V

Output Current into Outputs (LOW)............................. 20 mA

Static Discharge Voltage.......................................... > 2001V

(per MIL-STD-883, Method 3015)

Latch-up Current.................................................... > 200 mA

Operating Range