HM5425801B DDR SDRAM Technical Summary

Overview

The HM5425801B is a Double Data Rate (DDR) Synchronous Dynamic Random-Access Memory (SDRAM) device designed for high-speed data transfer applications. It belongs to the HM5425 series, which includes the HM5425161B and HM5425401B variants. These devices utilize a 2-bit prefetch pipelined architecture to achieve high-speed data transfer rates, synchronized with both rising and falling edges of the clock signal (CLK). The HM5425801B is optimized for performance and reliability, featuring a 2.5V power supply and SSTL-2 interface compatibility.

Key to its operation is the use of Data Strobe (DQS) signals for both read and write operations, ensuring robust data bus integrity. The device also includes an on-chip Delay Locked Loop (DLL), which can be enabled or disabled via an extended mode register setting, providing flexibility in system design.

Features

• JEDEC Standard Compatibility: Fully compliant with industry standards for DDR SDRAM.
• Power Supply: 2.5V operation for internal circuits and SSTL-2 interface.
• High-Speed Clock Frequencies: Supports 143 MHz, 133 MHz, 125 MHz, and 100 MHz operation.
• Data Synchronization: Data inputs, outputs, and Data Mask (DM) are synchronized with DQS for reliable data transfer.
• Multi-Bank Architecture: Four independent banks allow simultaneous and independent operation.
• Burst Operation: Supports burst read/write operations with programmable burst lengths of 2, 4, or 8.
• Burst Sequence Options: Configurable for sequential or interleave burst sequences.
• CAS Latency: Programmable CAS latency of 2 or 2.5 cycles.
• Refresh Modes: Supports both auto-refresh and self-refresh modes with 8192 refresh cycles (7.8 µs per row).
• Start Addressing: Supports even and odd start addressing for flexible memory access.

Applications

The HM5425801B is suitable for a wide range of applications requiring high-speed data transfer and reliable memory performance, including:

• Desktop and laptop computers
• Networking equipment (routers, switches)
• Graphics cards and gaming consoles
• Embedded systems and industrial automation
• Telecommunications infrastructure
• Data storage systems

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V_CC): -0.5V to +3.6V
• Input Voltage (V_IN): -0.5V to V_CC + 0.5V
• Operating Temperature Range: 0°C to +70°C (commercial grade)
• Storage Temperature Range: -55°C to +125°C

Recommended Operating Conditions

• V_CC (Core Voltage): 2.5V ± 0.2V
• V_CCQ (I/O Voltage): 2.5V ± 0.2V
• Clock Frequency: 100 MHz to 143 MHz (depending on variant)
• Input Reference Voltage (V_REF): 0.49 × V_CCQ to 0.51 × V_CCQ

Timing Parameters

• CAS Latency (CL): 2 or 2.5 clock cycles (programmable)
• t_RCD (RAS to CAS Delay): 20 ns (min)
• t_RP (Row Precharge Time): 20 ns (min)
• t_RAS (Row Active Time): 45 ns (min)
• t_RC (Row Cycle Time): 65 ns (min)

Package Information

Physical Dimensions

The HM5425801B is available in a 66-pin plastic Thin Small Outline Package (TSOP II), designated as TTP-66D. Key package dimensions include:

• Package Width: 10.16 mm (max)
• Package Length: 18.41 mm (max)
• Lead Pitch: 0.5 mm
• Lead Count: 66 pins

Pin Configuration

The HM5425801B features a 66-pin TSOP II package with the following pin assignments (top view):

• Pins 1-33: VCC, DQ0, VCCQ, DQ1, DQ2, VSSQ, DQ3, DQ4, VCCQ, DQ5, DQ6, VSSQ, DQ7, NC, VCCQ, DQSL, NC, VCC, NC, DML, WE, CAS, RAS, CS, NC, A14, A13, A10/AP, A0, A1, A2, A3, VCC, VSS
• Pins 34-66: DQ15, VSSQ, DQ14, DQ13, VCCQ, DQ12, DQ11, VSSQ, DQ10, DQ9, VCCQ, DQ8, NC, VSSQ, DQSU, NC, VREF, VSS, DMU, CLK, CLK, CKE, NC, A12, A11, A9, A8, A7, A6, A5, A4, VSS

Ordering Information

The HM5425801B is available in multiple variants, differentiated by clock frequency and package options:

• HM5425801BTT-75A: 143 MHz/133 MHz, 66-pin TSOP II
• HM5425801BTT-75B: 133 MHz/100 MHz, 66-pin TSOP II
• HM5425801BTT-10: 125 MHz/100 MHz, 66-pin TSOP II

Conclusion

The HM5425801B DDR SDRAM is a high-performance memory solution designed for applications requiring fast and reliable data transfer. With its JEDEC-compliant design, flexible burst modes, and multi-bank architecture, it is well-suited for a variety of computing and embedded systems. The device's robust electrical characteristics and compact TSOP II package make it an excellent choice for space-constrained designs.