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Overview

Description

The F1978 Digital Step Attenuator (DSA) featuring Glitch-Free™ technology improves system reliability and settling time. It has an attenuation range of 31.5dB with excellent accuracy and very low distortion and insertion loss. The product supports direct serial mode programming as well as conventional serial programming and parallel programming modes of direct and latched.

The F1978 DSA has identical RF performance as the F1975 DSA. The difference between F1978 and F1975 is that F1978 has an additional programming mode called Direct Serial Programming. Consult the "Programming" section of the F1978 datasheet or application note AN-945 "Comparison of F1975 and F1978 Digital Step Attenuator Serial Programming Methods".

Features

  • 5MHz to 3000MHz frequency range
  • Glitch-Free™ low transient overshoot
  • Low insertion loss 1.2dB at 1GHz
  • Excellent linearity +64dBm IIP3
  • Attenuation step error 0.1dB at 1GHz
  • Serial and parallel interface 31.5dB range
  • Low spurious design
  • 3V/5V supply, 1.8V/3.3V control logic
  • Fast settling time
  • Class 2 JEDEC ESD (2kV HBM)
  • 4mm x 4mm 20-TQFN package

Comparison

Applications

  • CATV infrastructure
  • CATV set-top boxes
  • CATV satellite modems
  • Data network equipment
  • Fiber networks

Documentation

Type Title Date
Datasheet PDF 3.77 MB
Guide PDF 2.24 MB
Guide PDF 2.83 MB
Report PDF 517 KB
Product Brief PDF 1.07 MB
Application Note PDF 193 KB
6 items

Design & Development

Software & Tools

Software Downloads

Type Title Date
Software & Tools - Software Log in to Download ZIP 169.81 MB
1 item

Boards & Kits

Models

ECAD Models

Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on products in the Product Options table. If a symbol or model isn't available, it can be requested directly from the website.

Diagram of ECAD Models

Videos & Training

IDT RF Product Benefits Overview

This video highlights the customer benefits of IDT's (acquired by Renesas) innovative RF products, which offer up to 10x improvement in RF performance. Key technologies include glitch-free technology for smooth transitions, flat-noise technology for consistent noise performance, zero-distortion technology for minimal intermodulation distortion, and more.

Transcript

Hello, my name is Dan Terlep. I'm a Product Definer in IDT's RF group. What I'm going to talk about are some of the customer benefits of IDT's technical innovations used in RF products. These are unique innovations that differentiate our products from competitive parts. Up to 10x improvement in RF performance can be obtained when using these devices in your designs. This technology is highly desired by equipment vendors and is protected by patents.

Glitch-free technology essentially eliminates the transient overshoot that can occur during mSv attenuation state transitions of standard digital step attenuators. Flat-noise technology maintains near constant noise performance [inaudible 00:00:48] reduced in our variable gain amplifiers, thus optimizing system level signal-to-noise performance. Zero-distortion technology practically eliminates intermodulation distortion in our RF mixers and amplifiers, enhancing the system's quality of service. Kz refers to constant impedance technology, which has implemented a new line of RF switches that allows 'hot switching' in TDD systems.

Additional benefits of using IDT's RF solutions include: enable screen networks with minimal power consumption; allow scaling from macrocells to microcells using the same device with reduced voltage, reduced current, or both; improves reliability by replacing gallium arsenite with silicon; improves data throughput by optimizing signal-to-noise performance and overall dynamic range; tolerates higher operating temperature than competitive devices.

Note that IDT's RF cards are used by all major cellular 3G and 4G equipment manufacturers for systems deployed all over the world. IDT's advanced RF portfolio using these technologies includes: mixers, digital step attenuators, RF switches, variable gain amplifiers, and modulators. These are silicon monolithic devices offered in QFN packages.

In summary, IDT's RF portfolio replaces gallium arsenite parts, results in higher reliability, provides better signal-to-noise performance, faster settling times, eliminates glitching and third-order intermodulation distortion, reduces DC power consumption, and operates at higher temperatures. Thank you for your time, and please make sure to visit IDT's RF website for a more complete look at our product portfolio. For additional information and support, please use the email shown.