HM62W8512BI - 4-Mbit (512K x 8) Static RAM

Overview

The Hitachi HM62W8512BI is a high-performance 4-Mbit static RAM organized as 512K words × 8 bits. Utilizing advanced Hi-CMOS process technology, this SRAM delivers higher density, improved performance, and reduced power consumption compared to conventional designs. The device operates on a single 3.3V power supply and features exceptionally low standby power dissipation, making it particularly suitable for battery backup applications. The HM62W8512BI is offered in a compact 32-pin TSOP II package with industrial temperature range support (-40°C to +85°C).

Key Features

• Memory Organization: 512K × 8-bit configuration
• Power Supply: Single 3.3V ± 0.3V operation
• Performance: 70ns/85ns maximum access time options
• Power Efficiency:
  • Active: 16.5 mW/MHz (typical)
  • Standby: 3.3 µW (typical)
• Fully Static Design: No clock or refresh required
• I/O Compatibility: Directly LV-TTL compatible inputs/outputs
• Three-State Outputs: Common data input/output
• Reliability: Industrial temperature range (-40°C to +85°C)
• Package: 32-pin TSOP II (400-mil width)

Applications

The HM62W8512BI is designed for applications requiring reliable, high-speed static memory with low power consumption:

• Battery-backed memory systems
• Industrial control systems
• Telecommunications equipment
• Embedded systems
• Medical devices
• Automotive electronics
• Portable computing devices
• Data logging systems

Electrical Characteristics

Absolute Maximum Ratings

• Power Supply Voltage (VCC): -0.5V to +4.6V
• Input Voltage (relative to VSS): -0.5V to VCC+0.5V (Note: -3.0V for pulse half-width ≤ 30ns)
• Power Dissipation: 1.0W
• Operating Temperature: -40°C to +85°C
• Storage Temperature: -55°C to +125°C

Recommended Operating Conditions

• Supply Voltage (VCC): 3.0V to 3.6V (3.3V nominal)
• Input High Voltage (VIH): 2.4V min to VCC+0.3V max
• Input Low Voltage (VIL): -0.3V min to 0.6V max

DC Characteristics (VCC = 3.3V ± 0.3V, VSS = 0V)

• Input Leakage Current (II): ±1 µA max
• Output Leakage Current (IOZ): ±1 µA max
• Operating Current (Active, ICC): 16.5 mW/MHz (typical)
• Standby Current (ISB): 3.3 µW (typical)

Package Information

32-Pin TSOP II (TTP-32D)

• Package Type: Plastic Thin Small Outline Package
• Width: 400 mil (10.16 mm)
• Pin Count: 32
• Lead Pitch: 0.8 mm
• Package Height: 1.2 mm max

Pin Configuration (Top View)

The pin arrangement follows the standard TSOP II configuration:

• Address Inputs (A0-A18): 19 address lines for memory access
• Data I/O (I/O0-I/O7): 8-bit bidirectional data bus
• Control Signals:
  • CS: Chip Select (active low)
  • OE: Output Enable (active low)
  • WE: Write Enable (active low)
• Power Pins:
  • VCC: Power supply (3.3V)
  • VSS: Ground

Functional Description

The HM62W8512BI is a fully static RAM that requires no refresh cycles or clock signals for operation. The memory array is organized as 512K words of 8 bits each, accessed through 19 address lines (A0-A18). The device features three-state outputs and common I/O pins, with separate control signals for read and write operations.

Operation Modes

• Not Selected (CS high): Device in standby mode with minimal power consumption
• Output Disabled (CS low, OE high): Outputs in high-impedance state
• Read Cycle (CS low, OE low, WE high): Data output enabled
• Write Cycle (CS low, WE low): Data input enabled (OE state doesn't matter)

Ordering Information

• HM62W8512BLTTI-7: 70ns access time, 32-pin TSOP II
• HM62W8512BLTTI-8: 85ns access time, 32-pin TSOP II

Reliability and Quality

The HM62W8512BI is designed for high reliability applications with industrial temperature range support. The device undergoes rigorous quality testing to ensure consistent performance across the specified operating conditions. The Hi-CMOS process technology provides excellent noise immunity and stable operation in electrically noisy environments.

Design Considerations

When implementing the HM62W8512BI in a system design, consider the following:

• Proper decoupling capacitors should be placed near the VCC pins
• Unused inputs should be tied to VCC or ground as appropriate
• Signal integrity should be maintained for high-speed operation
• For battery backup applications, ensure proper power switching circuitry