Rev 3 Board

Features:

• Low cost Analog to Digital card especially designed for seismic and other low frequency data recording
• 12 or 16 bit resolution A/D chip (Notes 1 & 5)
• Upgrade from 12 to 16 bit A/D chip by simply replacing A/D chip
• 8 analog input channels
• 4 digital input / output lines
• Compatible with SDR (Seismic Data Recorder) data logging software (Note 2)
• Programmable interrupt timer to generate interrupts between 100Khz to 500 seconds
  
  Optional Features
• WWV time correction circuitry for accurate time keeping when used with my SDR program

Specifications

• Analog Inputs
  • Channels: 8 single-ended inputs
  • Resolution: 12 or 16 bit successive approximation (Notes 1 & 5)
  • Input Range: 
    • Rev 2 Board: +- 5 volts input for full scale output
    • Rev 3 Board: +- 5 or +-10 volts,  jumper selectable
  • A/D Converter Chip:
    • Rev 2 Board: Burr-Brown ADS7806 (12 bit) or ADS7807 (16 bit)
    • Rev 3 Board: Linear Technology LTC1605CN (Note 5)
  • Accuracy: 12 bit +- 1 LSB 16 bit +- 3 LSB
  • Conversion Time: Rev 2 board 25us max / Rev 3 board 10us max
  • Input Impedance: 3.3k (Note 3)
• Digital Inputs and Outputs
  • Channels: 4 general purpose TTL compatible inputs and outputs
• Programmable Timer
  • Two channels of a Intel 8253/8254 16 bit programmable counter/timer chip
  • 4.000 Mhz reference oscillator.
  • Generates interrupts on IRQ lines 2, 3, 4, 5, 7, 10, 11, 12, 14, or 15
• WWV Time Correction Option
  • Tone Detector and bandpass filter tuned to 1000Hz. Used to detect the 800 ms tone at the top of the minute mark (Note 4)
  • +-20 millisecond time accuracy when locked to one of the WWV time signal (Note 4)
• Input / Output Connector
  • One 37 pin "D" type female connector for all inputs and outputs

Notes:
• 1: The 16 bit version has about 10x the dynamic range over the 12 bit version
• 2: SDR software produce event files compatible with my PSN event file viewer software WinQuake
• 3: Other input impedance possible by changing one resistor pack
• 4: When used with my SDR program and user supplied short-wave receiver 
• 5: Rev 3 board only comes in a 16 bit version

Cost:

Basic SDR version. This version does not have the WWV time correction circuitry:
	
	12 Bit version = $180.00       16 Bit version (Rev 2&3) = $230.00

SDR version with WWV time correction circuitry:

	12 Bit version = $195.00       16 Bit version (Rev 2&3) = $245.00

	Note: This option is not needed if you are going to use GPS Timing. 

Please add $8.00 for shipping and insurance within the US. International shipping 
will need to contact me and get a quote on the shipping to your country.

To order a board please contact me at the email address below or call me at: 1.650.365.7162

Additional Information

• Block Diagram (17k gif) of the A/D Board.
• Port address, jumper and I/O connector pinout information:  Rev 2 (17k gif)  Rev 3 (28k gif)
• Programming the A/D Board. This document describes how to use the A/D board with your own software.
• Data Sheets for the Analog To Digital Convert Chip used on this board:
  • Burr-Brown ADS7806 - 12 Bit Version
  • Burr-Brown ADS7807 - 16 Bit Version
  • Linear Technology LTC1605 16 Bit A/D Chip 
• How the WWV Time Option Works when the A/D board is used with SDR.
• WWV/WWVH Time Code (82k gif) format chart.
• WWVB and SDR. This page describes how to use Radio Shack's Radio Controlled Clock as a time reference for SDR.