Hitachi HM628128DI Series 1-Mbit SRAM

Overview

The Hitachi HM628128DI Series is a high-performance 1-Mbit static RAM (SRAM) organized as 131,072 words × 8 bits. Manufactured using advanced Hi-CMOS process technology, this SRAM delivers higher density, improved performance, and lower power consumption compared to conventional solutions. The HM628128DI is particularly well-suited for battery backup systems due to its ultra-low standby power dissipation. It is available in standard 32-pin plastic DIP (Dual In-line Package) and other package variations, making it versatile for a wide range of applications.

Features

• Single 5 V Supply: Operates at 5 V ± 10%, ensuring compatibility with standard power sources.
• Fast Access Time: Maximum access time of 70 ns, enabling high-speed data retrieval.
• Low Power Consumption:
  • Active mode: 30 mW/MHz (typical)
  • Standby mode: 10 µW (typical), ideal for battery-operated systems.
• Completely Static Memory: No clock or timing strobe required, simplifying design and integration.
• Equal Access and Cycle Times: Ensures consistent performance for read and write operations.
• Common Data Input and Output: Three-state output for easy bus interfacing.
• TTL Compatibility: All inputs are directly compatible with TTL logic levels.
• Battery Backup Operation: Features two chip selection inputs for efficient power management in backup scenarios.
• Wide Temperature Range: Operates reliably from –40°C to +85°C, suitable for industrial and automotive applications.

Applications

The HM628128DI Series is designed for a broad spectrum of applications, including but not limited to:

• Battery Backup Systems: Due to its ultra-low standby power, it is ideal for memory retention in portable and backup power applications.
• Industrial Control Systems: Reliable operation across a wide temperature range makes it suitable for harsh environments.
• Embedded Systems: Used in microcontrollers and DSP-based systems where fast, static memory is required.
• Telecommunications: High-speed access and low power consumption are beneficial for networking equipment.
• Automotive Electronics: Robust performance under extreme temperatures supports automotive computing needs.
• Consumer Electronics: Found in devices requiring non-volatile or low-power memory solutions.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V_CC): –0.5 V to +7.0 V
• Input Voltage (V_IN): –0.5 V to V_CC + 0.5 V
• Operating Temperature Range (T_OPR): –40°C to +85°C
• Storage Temperature Range (T_STG): –65°C to +150°C

Recommended Operating Conditions

• Supply Voltage (V_CC): 4.5 V to 5.5 V
• Input High Voltage (V_IH): 2.2 V min
• Input Low Voltage (V_IL): 0.8 V max
• Operating Temperature: –40°C to +85°C

DC Characteristics

• Input Leakage Current (I_LI): ±1 µA max at V_IN = 0 V to V_CC
• Output Leakage Current (I_LO): ±1 µA max at V_OUT = 0 V to V_CC
• Standby Current (I_SB): 10 µA max at V_CC = 2.0 V

AC Characteristics

• Read Cycle Time (t_RC): 70 ns max
• Access Time (t_AA): 70 ns max
• Write Cycle Time (t_WC): 70 ns max
• Write Pulse Width (t_WP): 50 ns min

Package Information

The HM628128DI Series is available in multiple package options to accommodate different design requirements:

• 32-Pin Plastic DIP (Dual In-line Package): Standard through-hole package for easy prototyping and assembly.
• 32-Pin SOP (Small Outline Package): Surface-mount option for space-constrained applications.
• 32-Pin TSOP (Thin Small Outline Package): Ultra-thin profile for high-density PCB designs.

Pin Configuration

The 32-pin configuration includes:

• Address Pins (A0–A16): 17 address lines for 131,072-word addressing.
• Data I/O Pins (I/O0–I/O7): 8-bit bidirectional data bus.
• Control Pins: Chip Enable (CE), Output Enable (OE), and Write Enable (WE) for memory management.
• Power Pins: V_CC (5 V supply) and GND (ground).

Ordering Information

The HM628128DI Series is available under the following part numbers, with variations based on package type and temperature range:

• HM628128DI-70: 70 ns access time, commercial temperature range (0°C to +70°C).
• HM628128DI-70L: 70 ns access time, industrial temperature range (–40°C to +85°C).
• HM628128DI-70Z: 70 ns access time, available in TSOP package.

Conclusion

The Hitachi HM628128DI Series 1-Mbit SRAM is a versatile, high-performance memory solution designed for applications requiring fast access times, low power consumption, and reliable operation across a wide temperature range. Its robust feature set and multiple package options make it an excellent choice for industrial, automotive, and consumer electronics applications. With its battery backup compatibility and TTL-compatible inputs, the HM628128DI Series stands out as a reliable and efficient static RAM solution.