62W16256B

Technical Summary: Hitachi HM62W16256B Series 4-Mbit Static RAM

Overview

The Hitachi HM62W16256B Series is a high-performance 4-Mbit static RAM organized as 262,144 words × 16 bits. Manufactured using advanced Hi-CMOS process technology, this SRAM offers a combination of high density, high performance, and low power consumption. It is particularly well-suited for battery backup systems due to its low standby power dissipation. The device is available in a standard 44-pin plastic TSOPII package, making it ideal for space-constrained applications.

Features

• Single 3.3V Supply: Operates at 3.3V ± 0.3V, making it compatible with modern low-voltage systems.
• Fast Access Time: Available in 55 ns and 70 ns (max) variants to suit different performance requirements.
• Low Power Consumption:
  • Active Power Dissipation: 9.9 mW (typical)
  • Standby Power Dissipation: 3.3 µW (typical)
• Completely Static Memory: No clock or timing strobe required, simplifying system design.
• Equal Access and Cycle Times: Ensures consistent performance for read and write operations.
• Common Data Input and Output: Features three-state output for easy bus interfacing.
• Battery Backup Operation: Dual chip selection (CS1 and CS2) enhances battery backup efficiency.
• Wide Temperature Range: Suitable for industrial and commercial applications.

Applications

The HM62W16256B Series is designed for a wide range of applications, including but not limited to:

• Battery-powered devices and portable electronics
• Embedded systems and microcontrollers
• Industrial control systems
• Telecommunications equipment
• Networking devices
• Medical instrumentation
• Automotive electronics

Electrical Characteristics

The following table summarizes the key electrical characteristics of the HM62W16256B Series:

• Supply Voltage (V_CC): 3.3V ± 0.3V
• Operating Current (I_CC): 3 mA (typical) at 55 ns access time
• Standby Current (I_SB): 1 µA (typical) at 3.3V
• Input/Output Voltage Levels:
  • High-Level Input Voltage (V_IH): 2.0V (min)
  • Low-Level Input Voltage (V_IL): 0.8V (max)
  • High-Level Output Voltage (V_OH): 2.4V (min) at I_OH = -2.0 mA
  • Low-Level Output Voltage (V_OL): 0.4V (max) at I_OL = 2.0 mA

Package Information

The HM62W16256B Series is available in a 44-pin plastic TSOPII package (normal-bend type, TTP-44DB). Key package details include:

• Package Dimensions: 400-mil width, 44-pin configuration
• Pin Count: 44
• Package Type: Thin Small Outline Package (TSOPII)
• Ordering Information:
  • HM62W16256BLTT-5: 55 ns access time
  • HM62W16256BLTT-7: 70 ns access time
  • HM62W16256BLTT-5SL: 55 ns access time (special order)
  • HM62W16256BLTT-7SL: 70 ns access time (special order)

Pin Arrangement and Description

The 44-pin TSOPII package features the following pin configuration (top view):

• Address Inputs (A0-A17): 18-bit address bus for memory access
• Data Input/Output (I/O0-I/O15): 16-bit bidirectional data bus
• Chip Select (CS1, CS2): Enables device selection for read/write operations
• Write Enable (WE): Controls write operations
• Output Enable (OE): Controls output buffer
• Byte Select (LB, UB): Selects lower or upper byte for byte-wise operations
• Power Supply (V_CC): 3.3V power supply
• Ground (V_SS): Ground reference

Block Diagram

The HM62W16256B Series features a well-organized internal block diagram, including:

• Address decoder for row and column selection
• Memory cell array (262,144 × 16)
• Input/output buffers for data handling
• Control logic for WE, OE, CS1, and CS2 signals
• Power management circuitry for low-power operation

Conclusion

The Hitachi HM62W16256B Series 4-Mbit static RAM is a versatile and high-performance memory solution for applications requiring low power consumption, high density, and reliable operation. Its advanced Hi-CMOS process technology ensures efficient performance, while the 44-pin TSOPII package offers a compact footprint for space-constrained designs. With features like battery backup support and fast access times, this SRAM is an excellent choice for a wide range of industrial, commercial, and portable applications.