Hitachi HM628512B 4-Mbit Static RAM (512K x 8-bit)

Overview

The Hitachi HM628512B is a high-performance 4-Mbit static RAM (SRAM) organized as 512K words by 8 bits. Manufactured using advanced 0.35 µm Hi-CMOS process technology, this device offers a combination of high density, low power consumption, and reliable performance. The HM628512B is designed for applications requiring fast access times and battery backup capability, making it ideal for embedded systems, industrial controls, and portable electronics.

Available in multiple package options, including 525-mil SOP, 400-mil TSOP TYPE II, and 600-mil plastic DIP, the HM628512B provides flexibility for high-density PCB mounting. Its fully static operation eliminates the need for clock signals or refresh cycles, simplifying system design.

Features

• Single 5V Power Supply: Simplifies power management in 5V-based systems.
• High-Speed Access Time: Maximum access times of 55 ns and 70 ns ensure fast data retrieval.
• Low Power Consumption:
  • Active mode: 50 mW/MHz (typical)
  • Standby mode: 10 µW (typical), ideal for battery backup applications.
• Fully Static Operation: No clock or refresh requirements, ensuring ease of use.
• Equal Access and Cycle Times: Simplifies timing considerations in system design.
• Three-State Output: Common data input/output with high-impedance state for bus sharing.
• TTL Compatibility: All inputs and outputs are directly compatible with TTL logic levels.
• Battery Backup Support: Designed for reliable operation in power-sensitive applications.

Applications

The HM628512B is well-suited for a wide range of applications, including:

• Embedded Systems: Microcontroller-based designs requiring fast, non-volatile memory.
• Industrial Controls: PLCs, automation systems, and data loggers.
• Portable Electronics: Battery-powered devices such as medical instruments and handheld meters.
• Telecommunications: Networking equipment and routers needing high-speed SRAM.
• Automotive Systems: Infotainment and engine control units (ECUs).
• Legacy Upgrades: Replacement for older SRAMs in industrial and consumer electronics.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V_CC): -0.3V to +7.0V
• Input Voltage (V_IN): -0.3V to V_CC + 0.3V
• Operating Temperature Range: -40°C to +85°C
• Storage Temperature Range: -65°C to +150°C

Recommended Operating Conditions

• Supply Voltage (V_CC): 4.5V to 5.5V
• Input High Voltage (V_IH): 2.2V min
• Input Low Voltage (V_IL): 0.8V max
• Operating Temperature: Commercial (0°C to +70°C) or Industrial (-40°C to +85°C)

DC Characteristics

• Standby Current (I_SB): 2 µA (max) at V_CC = 3.0V
• Operating Current (I_CC): 25 mA (max) at 55 ns access time
• Output High Voltage (V_OH): 2.4V min at I_OH = -2.0 mA
• Output Low Voltage (V_OL): 0.4V max at I_OL = 2.0 mA

AC Characteristics

• Read Cycle Time (t_RC): 55 ns / 70 ns (max)
• Write Cycle Time (t_WC): 55 ns / 70 ns (max)
• Address Setup Time (t_AS): 0 ns (min)
• Chip Select to Output Valid (t_CO): 55 ns / 70 ns (max)

Package Information

The HM628512B is available in three industry-standard packages, providing flexibility for different PCB layouts and assembly processes:

525-mil SOP (Small Outline Package)

• Footprint Pitch Width: 525 mil (13.335 mm)
• Pin Count: 32
• Package Dimensions: 13.0 mm x 7.6 mm (body)
• Mounting Style: Surface-mount (SMD)

400-mil TSOP TYPE II (Thin Small Outline Package)

• Footprint Pitch Width: 400 mil (10.16 mm)
• Pin Count: 32
• Package Thickness: 1.2 mm (max)
• Mounting Style: Surface-mount (SMD), suitable for space-constrained designs.

600-mil Plastic DIP (Dual In-line Package)

• Footprint Pitch Width: 600 mil (15.24 mm)
• Pin Count: 32
• Package Dimensions: 42.0 mm x 10.16 mm (body)
• Mounting Style: Through-hole, ideal for prototyping and legacy systems.

Conclusion

The Hitachi HM628512B is a versatile and high-performance 4-Mbit SRAM that combines speed, low power consumption, and flexible packaging options. Its fully static operation and TTL compatibility make it an excellent choice for a wide range of applications, from industrial controls to portable electronics. With robust electrical characteristics and support for battery backup, the HM628512B is a reliable solution for demanding memory requirements.