Overview
The SN74S1051DR is a 12-bit Schottky barrier diode bus-termination array produced by Texas Instruments. This component is designed to reduce reflection noise on memory bus lines and is particularly suited for bus-oriented systems. It consists of a high-speed Schottky diode array that can be clamped to VCC and/or GND, making it effective in suppressing negative transients caused by transmission-line reflections, crosstalk, and switching noise. Although the SN74S1051 has been discontinued, its design and functionality remain relevant for understanding and addressing noise issues in digital systems.
Key Specifications
| Parameter | Test Conditions | Min | Max | Unit | |
|---|---|---|---|---|---|
| Steady-state reverse voltage, VR | - | - | - | 7 | V |
| Continuous forward current, IF | Any D terminal from GND or to VCC | - | - | 200 | mA |
| Static forward voltage, VF (To VCC) | IF = 18 mA | 0.85 | 1.05 | - | V |
| Static forward voltage, VF (To VCC) | IF = 50 mA | 1.05 | 1.3 | - | V |
| Static forward voltage, VF (From GND) | IF = 18 mA | 0.75 | 0.95 | - | V |
| Static forward voltage, VF (From GND) | IF = 50 mA | 0.95 | 1.2 | - | V |
| Peak forward voltage, VFM | IF = 200 mA | - | - | 1.45 | V |
| Reverse recovery time, trr | IF = 10 mA, IRM(REC) = 10 mA, IR(REC) = 1 mA, RL = 100 Ω | 8 | 16 | - | ns |
| Operating Temperature Range | - | - | - | 0 to 70 | °C |
Key Features
- High-Speed Schottky Diode Array: The SN74S1051DR features a 12-bit high-speed Schottky diode array, making it suitable for clamping to VCC and/or GND to reduce reflection noise on memory bus lines.
- Low Forward Voltage Drop: The diodes have a low forward voltage drop, which helps in minimizing power consumption and ensuring efficient operation.
- Effective Noise Suppression: The component is designed to suppress negative transients caused by transmission-line reflections, crosstalk, and switching noise, ensuring stable operation of memory devices and clocked systems.
- Various Package Options: Available in several package types including SOIC, PDIP, SOP, and TSSOP, providing flexibility in design and implementation.
- RoHS Compliance: The device is RoHS compliant, ensuring environmental sustainability.
Applications
The SN74S1051DR is primarily used in bus-oriented systems to reduce reflection noise and suppress negative transients. It is particularly useful in:
- Memory Bus Lines: For DRAMs, SRAMs, EPROMs, and other memory devices to prevent improper operation due to negative transients.
- Clocked Devices: On the CLOCK lines of many clocked devices to ensure stable and reliable operation.
- Transmission Lines: At the end of transmission lines or long stubs branching off main transmission lines to minimize the impact of reflections and crosstalk.
Q & A
- What is the primary function of the SN74S1051DR?
The primary function of the SN74S1051DR is to reduce reflection noise on memory bus lines and suppress negative transients caused by transmission-line reflections, crosstalk, and switching noise.
- What types of packages are available for the SN74S1051DR?
The SN74S1051DR is available in SOIC, PDIP, SOP, and TSSOP packages.
- What is the operating temperature range of the SN74S1051DR?
The operating temperature range is from 0°C to 70°C.
- What is the maximum steady-state reverse voltage for the SN74S1051DR?
The maximum steady-state reverse voltage is 7 V.
- What is the maximum continuous forward current for the SN74S1051DR?
The maximum continuous forward current is 200 mA.
- Why is the SN74S1051DR preferred over resistor termination schemes?
The SN74S1051DR is preferred because it does not increase power consumption or degrade the output high level, and it does not add propagation delays like series damping resistors do.
- Is the SN74S1051DR still in production?
No, the SN74S1051DR has been discontinued by Texas Instruments.
- What are the benefits of using Schottky diodes in the SN74S1051DR?
Schottky diodes offer low forward voltage drop, high speed, and effective noise suppression, making them ideal for reducing reflection noise and negative transients.
- How does the SN74S1051DR reduce negative transients on transmission lines?
The diodes conduct current when the voltage reaches a negative value large enough to turn them on, thereby suppressing negative transients and stabilizing the signal.
- Is the SN74S1051DR RoHS compliant?
