SN75976A中文资料9 通道差动收发器数据手册TI规格书

描述 Description

The SN75976A is an improved replacement for the industry's first 9-channel RS-485 transceiver -- the SN75LBC976. The A version offers improved switching performance, a smaller package, and higher ESD protection. The SN75976A is offered in two versions. The '976A2 skew limits of 4 ns for the differential drivers and 5 ns for the differential receivers complies with the recommended skew budget of the Fast-20 SCSI standard for data transfer rates up to 20 million transfers per second. The '976A1 supports the Fast SCSI skew budget for 10 million transfers per second. The skew limit ensures that the propagation delay times, not only from channel-to-channel but from device-to-device, are closely matched for the tight skew budgets associated with high-speed parallel data buses. The patented thermal enhancements made to the 56-pin shrink small-outline package (SSOP) of the SN75976 have been applied to the new, thin shrink, small-outline package (TSSOP). The TSSOP package offers even less board area requirements than the SSOP while reducing the package height to 1 mm. This provides more board area and allows component mounting to both sides of the printed circuit boards for low-profile, space-restricted applications such as small form-factor hard disk drives. In addition to speed improvements, the '976A can withstand electrostatic discharges exceeding 12 kV using the human-body model, and 600 V using the machine model of MIL-PRF-38535, Method 3015.7 on the RS-485 I/O terminals. This is six times the industry standard and provides protection from the noise that can be coupled into external cables. The other terminals of the device can withstand discharges exceeding 4 kV and 400 V respectively.Each of the nine channels of the '976A typically meet or exceed the requirements of EIA RS-485 (1983) and ISO8482-1987/TIA TR30.2 referenced by American National Standard of Information (ANSI) Systems, X3.131-1994 (SCSI-2) standard, X2.277-1996 (Fast-20 Parallel Interface), and the Intelligent Peripheral Interface Physical Layer-ANSI X3.129-1986 standard.The SN75976A is characterized for operation over an ambient air temperature range of 0°C to 70°C. The SN55976A is characterized for operation over an ambient air temperature range of -55°C to 125°C.

特性 Features

• Improved Speed and Package Replacement for the SN75LBC976
• Designed to Operate at up to 20 Million Data Transfers per Second (Fast-20 SCSI)
• Nine Differential Channels for the Data and Control Paths of the Small Computer Systems Interface (SCSI) and Intelligent Peripheral Interface (IPI)
• SN75976A Packaged in Shrink Small-Outline Package with 25-Mil Terminal Pitch (DL) and Thin Shrink Small-Outline Package with 20-Mil Terminal Pitch (DGG)
• SN55976A Packaged in a 56-Pin Ceramic Flat Pack (WD)
• Two Skew Limits Available
• ESD Protection on Bus Terminals Exceeds 12 kV
• Low Disabled Supply Current 8 mA Typ
• Thermal Shutdown Protection
• Positive- and Negative-Current Limiting
• Power-Up/Down Glitch Protection

简介

SN75976A属于集成电路（IC）的驱动器接收器收发器。由TI制造生产的SN75976A驱动器，接收器，收发器该系列产品的主要功能是提供必需的硬件资源，以通过延长电缆或印制线进行通信。确切的功能会因所采用的通信协议而异，可能包括诸如瞬态抑制之类的功能，这些功能对于通信用途可能并非绝对必要，但对于可能的使用环境却是明智之选。