DEMO MANUAL DC847A LTC2446 24-Bit High Speed 4-/8-Channel ADCs with Selectable Multiple Reference Inputs Description The LTC 2446 is a 4-/8-channel, high speed, 24-bit The DC847A is a member of Linear Technologys QuikEval ADC with ten selectable speed/resolution modes from family of demonstration boards. It is designed to allow easy 6.9Hz/280nV to 3.5kHz/25V . Key DC specifica- evaluation of the LTC2446 and may be connected directly RMS RMS tions include 5ppm INL, 5V offset, 10ppm full-scale to the target applications analog signals while using the error and 20nV/C offset drift. In the 6.9Hz/200nV DC590 USB serial controller board and supplied software RMS mode, input normal mode rejection of 50Hz and 60Hz to measure performance. The exposed ground planes allow noise is better than 87dB. The accuracy (offset, full-scale, proper grounding to prototype circuitry. After evaluating linearity, drift) and power dissipation are independent of with LTCs software, the digital signals can be connected the speed selected. The LTC2446 also has four reference to the applications processor/controller for development inputs dedicated to the four differential input channels of the serial interface. and corresponding pairs of single-ended input channels. Design files for this circuit board are available at This allows the inputs to have different reference sources, DEMO MANUAL DC847A Quick s Dp n n Connect the DC847A to a DC590 USB serial controller Click the slider at the bottom of the strip chart display using the supplied 14-conductor ribbon cable. to change the oversample ratio (OSR) which will, in turn, change the data output rate. n Connect the DC590 to a host PC with a standard USB A/B cable. Tools are available for logging data, changing reference voltage, changing the number of points in the strip chart n Run the evaluation software supplied with the DC590 and histogram, and changing the number of points aver- or download it from www.linear.com/software. The aged for the DVM display. correct program will be loaded automatically. n Click the Collect button to start reading the input voltage. Figure 2. QuikEval Software Screenshot dc847af 2 ure roce tart