HM5225165B Technical Summary

HM5225165B 256-Mbit SDRAM Technical Summary

Overview

The Hitachi HM5225165B is a high-performance 256-Mbit Synchronous DRAM (SDRAM) component designed for applications requiring high-speed data transfer and efficient memory management. Organized as 4,194,304 words × 16 bits × 4 banks, this SDRAM offers flexible memory configurations suitable for various computing and embedded systems. The device operates with a 3.3V power supply and features a low-voltage TTL (LVTTL) interface, making it compatible with modern digital systems.

All inputs and outputs are synchronized to the rising edge of the clock input, ensuring precise timing and reliable data transfer. The HM5225165B is available in a standard 54-pin plastic TSOP II package, providing a compact and industry-standard form factor for easy integration into system designs.

Features

Memory Organization: 256-Mbit capacity organized as 4,194,304 words × 16 bits × 4 banks
Power Supply: 3.3V ± 0.3V
Clock Frequency: Up to 133 MHz (HM5225165B-75) or 100 MHz (HM5225165B-A6/B6)
Interface: LVTTL compatible
Bank Architecture: 4 independent banks supporting simultaneous operation
Burst Operations:
- Burst read/write operation
- Burst read/single write operation
Programmable Burst Length: 1, 2, 4, or 8
Burst Sequence Options:
- Sequential (BL = 1/2/4/8)
- Interleave (BL = 1/2/4/8)
CAS Latency: Programmable to 2 or 3 cycles
Data Masking: Byte control via DQMU/DQML (HM5225165B)
Refresh:
- 8,192 refresh cycles every 64ms
- Auto refresh and self refresh modes

Applications

The HM5225165B is suitable for a wide range of applications requiring high-speed memory access and efficient data handling:

Computer systems and workstations
Networking equipment (routers, switches)
Telecommunications infrastructure
Embedded systems
Graphics and video processing
Industrial control systems
Automotive electronics
Consumer electronics

Electrical Characteristics

Absolute Maximum Ratings

Supply Voltage (VDD, VDDQ): -0.5V to +4.6V
Input Voltage (VI): -0.5V to VDDQ + 0.5V
Output Voltage (VO): -0.5V to VDDQ + 0.5V
Operating Temperature: 0°C to +70°C
Storage Temperature: -55°C to +125°C

Recommended Operating Conditions

Supply Voltage (VDD, VDDQ): 3.3V ± 0.3V
Input High Voltage (VIH): 2.0V min (VDDQ = 3.0V)
Input Low Voltage (VIL): 0.8V max (VDDQ = 3.0V)
Operating Temperature Range: 0°C to +70°C

DC Characteristics

Input Leakage Current (II): ±1μA max
Output Leakage Current (IOZ): ±1μA max
Operating Current (IDD): 120mA max (133MHz operation)
Standby Current (IDD2): 20mA max (LVTTL inputs)
Self Refresh Current (IDD6): 400μA max

Package Information

54-pin TSOP II Package

Package Type: Plastic Thin Small Outline Package (TSOP) II
Pin Count: 54
Package Dimensions: 22.2mm × 10.2mm × 1.2mm (typical)
Pin Pitch: 0.8mm
Lead Material: Alloy 42 or copper alloy
Lead Finish: Matte tin or solder plating

Pin Configuration

The 54-pin TSOP II package includes the following key signal groups:

Clock and control signals (CLK, CKE, CS, RAS, CAS, WE)
Address inputs (A0-A11)
Bank address inputs (BA0, BA1)
Data input/output (DQ0-DQ15)
Data mask (DQMU, DQML)
Power supply (VDD, VDDQ)
Ground (VSS, VSSQ)

Ordering Information

The HM5225165B is available in different speed grades and variants:

HM5225165B-75: 133MHz operation
HM5225165B-A6: 100MHz operation
HM5225165B-B6: 100MHz operation (alternate)

Additional variants include:

HM5225805B: 8-bit organization (8,388,608 words × 8 bits × 4 banks)
HM5225405B: 4-bit organization (16,777,216 words × 4 bits × 4 banks)

Functional Description

The HM5225165B operates with a synchronous interface where all inputs are sampled at the rising edge of the clock signal. The device features four independent memory banks that can be accessed simultaneously, improving overall memory bandwidth.