Technical Summary: 62G36256 Synchronous SRAM

Overview

The 62G36256 is a high-performance 8M-bit synchronous static random-access memory (SRAM) designed for applications requiring high-speed data access and low latency. It operates at a frequency range of 200MHz to 250MHz and supports a 3.3V power supply with a tolerance of +10% and -5%. The device features a byte-write capability, programmable impedance output drivers, and HSTL-compatible I/O, making it suitable for high-speed computing and networking applications.

Features

• 3.3V Operation: Supports a voltage range of 3.3V ±10%/-5% for core and I/O power supplies.
• High-Density Memory: 8M-bit organization, configurable as 256K x 36 or other user-selectable options.
• High-Speed Performance: Operates at frequencies between 200MHz and 250MHz.
• Synchronous Operation: All inputs and outputs are synchronized to the rising edge of the clock signal.
• Byte Write Control: Four byte write enable signals (SWEa, SWEb, SWEc, SWEd) for flexible data masking.
• HSTL-Compatible I/O: Supports High-Speed Transceiver Logic (HSTL) for improved signal integrity.
• Programmable Impedance Output Drivers: Allows tuning of output drive strength to match transmission line requirements.
• Differential HSTL Clock Inputs: Enhances clock signal integrity and reduces jitter.
• Asynchronous Output Control: Features an asynchronous output enable (G) for immediate tri-state control.
• Sleep Mode: Asynchronous sleep mode (ZZ) for power savings during idle periods.
• Package: Available in a 119-pin BGA package (14mm x 22mm footprint).
• Boundary Scan (JTAG): Limited support for IEEE 1149.1 boundary scan testing.

Applications

The 62G36256 is ideal for applications requiring high-speed, low-latency memory access, including:

• Networking equipment (routers, switches, and line cards)
• Telecommunications infrastructure
• High-performance computing systems
• Data center hardware
• Embedded systems with stringent memory performance requirements
• Test and measurement equipment

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (VDD, VDDQ): -0.5V to +4.0V
• Input Voltage: -0.5V to VDDQ + 0.5V
• Operating Temperature Range: 0°C to +70°C (commercial) or -40°C to +85°C (industrial)
• Storage Temperature: -55°C to +125°C

Recommended Operating Conditions

• Core Supply Voltage (VDD): 3.3V ±10%/-5%
• I/O Supply Voltage (VDDQ): 3.3V ±10%/-5%
• Reference Voltage (VREF): 0.5 x VDDQ
• Clock Frequency: 200MHz to 250MHz

Timing Parameters

• Clock Cycle Time (t_CK): 4.0ns (250MHz) to 5.0ns (200MHz)
• Access Time (t_AA): 2.2ns (HM62G36256BP-4) or 2.5ns (HM62G36256BP-5)
• Output Hold Time (t_OH): 0.5ns (min)
• Input Setup Time (t_IS): 0.7ns (max)
• Input Hold Time (t_IH): 0.3ns (min)

Package Information

119-Pin BGA (BP-119A)

• Package Dimensions: 14mm x 22mm body size with 1.27mm ball pitch.
• Ball Count: 119 solder balls arranged in a staggered grid.
• Material: Thermally enhanced mold compound with copper heat spreader.
• RoHS Compliance: Yes, lead-free and halogen-free.

Pinout Description

The 62G36256 features a comprehensive pinout with dedicated functions for address inputs, data I/O, control signals, and power supplies. Key pins include:

• SA0-SA17: Address inputs (18-bit address bus).
• DQa0-DQa8, DQb0-DQb8, DQc0-DQc8, DQd0-DQd8: Data I/O pins (36-bit data bus).
• K, K: Differential clock inputs (HSTL compatible).
• G: Asynchronous output enable (active low).
• ZZ: Sleep mode control (active high).
• SWEa, SWEb, SWEc, SWEd: Byte write enable signals.
• VDD, VSS, VDDQ, VREF: Power and ground pins.

Functional Description

The 62G36256 operates in a synchronous manner, with all data transfers occurring on the rising edge of the clock signal (K). The device supports a late-write protocol, where write data is registered one cycle after the address and control signals. This allows for efficient pipelining in high-speed systems. The memory array is organized into four byte-wide sections, each controlled by its own write enable signal (SWEa-SWEd).

Block Diagram Overview

The internal architecture consists of the following key blocks:

• Memory Cell Array: 256K x 36-bit organization with redundant cells for improved yield.
• Row and Column Decoders: Hierarchical decoding for fast access times.
• Input/Output Registers: Pipeline registers for addresses, data, and control signals.
• Impedance Control Logic: Adjusts output driver strength based on ZQ pin reference.
• JTAG Interface: Limited boundary scan capability for board-level testing.

Ordering Information

The device is available in different speed grades and package options:

• HM62G36256BP-4: 4.0ns cycle time (250MHz), 2.2ns access time.
• HM62G36256BP-5: 5.0ns cycle time (200MHz), 2.5ns access time.

Both variants use the same 119-pin BGA package (BP-119A).