6216255H
HM6216255H Series 4-Mbit High-Speed Static RAM
Overview
The HM6216255H Series is a high-performance 4-Mbit static RAM (SRAM) organized as 256K words × 16 bits. Designed using advanced CMOS process technology (4-transistor + 2-poly resistor memory cell) and high-speed circuit design techniques, this component achieves exceptional access times while maintaining low power consumption. The device is particularly well-suited for applications requiring high-speed, high-density memory with wide bit-width configurations, such as cache and buffer memory in computing systems.
The HM6216255H is available in two package options: a 400-mil 44-pin plastic Small Outline J-lead (SOJ) package and a 400-mil 44-pin plastic Thin Small Outline Package Type II (TSOPII). The device operates from a single 5V power supply with ±10% tolerance, making it compatible with standard TTL logic levels.
Features
- High-Speed Performance: Maximum access times of 10 ns, 12 ns, or 15 ns variants available
- Wide Operating Voltage: Single 5.0 V ± 10% power supply
- Fully Static Operation: No clock or refresh required
- TTL Compatibility: All inputs and outputs directly compatible with TTL levels
- Low Power Consumption:
- Operating current: 160-200 mA (max depending on speed grade)
- TTL standby current: 50-70 mA (max)
- CMOS standby current: 5 mA (max), 1.2 mA (max) for L-version
- Data Retention:
- Data retention current: 0.8 mA (max) for L-version
- Data retention voltage: 2 V (min) for L-version
- Package Options: 44-pin SOJ (CP-44D) and 44-pin TSOPII (TTP-44DE)
- Byte Control: Upper byte (UB) and lower byte (LB) select functionality
Applications
The HM6216255H Series is designed for high-performance applications requiring fast, reliable static RAM:
- Cache memory in computing systems
- Buffer memory for high-speed data processing
- Networking equipment requiring fast access memory
- Industrial control systems
- Telecommunications infrastructure
- Embedded systems requiring non-volatile memory backup
- High-performance gaming systems
- Medical imaging equipment
Electrical Characteristics
Absolute Maximum Ratings
- Supply voltage (VCC): -0.5 V to +7.0 V
- Input voltage: -0.5 V to VCC + 0.5 V
- Operating temperature: 0°C to +70°C
- Storage temperature: -55°C to +125°C
Recommended Operating Conditions
- Supply voltage (VCC): 4.5 V to 5.5 V
- Input high voltage (VIH): 2.2 V min
- Input low voltage (VIL): 0.8 V max
- Operating temperature: 0°C to +70°C
DC Characteristics
- Input leakage current: ±1 μA max
- Output leakage current: ±1 μA max
- Output high voltage (VOH): 2.4 V min (I OH = -5 mA)
- Output low voltage (VOL): 0.4 V max (I OL = 8 mA)
AC Characteristics
- Read cycle time: Equal to access time (10/12/15 ns)
- Write cycle time: Equal to access time (10/12/15 ns)
- Address setup time: 5 ns min
- Address hold time: 5 ns min
- Chip select to output valid: 10/12/15 ns max
- Output enable to output valid: 5 ns max
Package Information
44-pin Plastic SOJ (CP-44D)
- Package dimensions: 18.41 mm × 10.16 mm body
- Lead pitch: 1.27 mm
- Lead count: 44 (22 per side)
- Package thickness: 3.05 mm max
- Moisture sensitivity level: MSL 3
44-pin Plastic TSOPII (TTP-44DE)
- Package dimensions: 18.41 mm × 10.16 mm body
- Lead pitch: 0.8 mm
- Lead count: 44 (22 per side)
- Package thickness: 1.2 mm max
- Moisture sensitivity level: MSL 3
Pin Configuration and Description
Pin Arrangement (Top View)
The HM6216255H features a center VCC and VSS type pinout for improved power distribution:
- Address Inputs (A0-A17): 18-bit address bus
- Data Input/Output (I/O1-I/O16): 16-bit bidirectional data bus
- Control Pins:
- CS: Chip select (active low)
- OE: Output enable (active low)
- WE: Write enable (active low)
- UB: Upper byte select (active low)
- LB: Lower byte select (active low)
- Power Pins:
- VCC: Power supply (5V)
- VSS: Ground
- NC: No connection (reserved for future use)
Functional Description
The HM6216255H is a fully static RAM that requires no refresh cycles or clock signals for operation. The memory array is organized as 256 rows × 8 columns × 128 blocks × 16 bits (totaling 4,194,304 bits). The device features:
- Byte Control: The UB and LB pins allow individual access to the upper and lower bytes of the 16-bit word
- Three-State Outputs: All I/O pins enter high-impedance state when the device is deselected (CS high) or outputs are disabled (OE high)
- Power-Down Mode: When CS is high, the device enters standby mode with significantly reduced power consumption
