DEMO MANUAL DC1012A LTC2499/LTC2497/LTC2495 24-/16-Bit Easy Drive 8-/16- Channel Delta Sigma 2 ADC with I C Interface DESCRIPTION Demonstration circuit 1012A-A features the LTC 2499 DC1012A is a member of Linear Technologys QuikEval 8-/16-channel, 24-bit delta sigma ADC with Easy Drive family of demonstration boards. It is designed to allow inputs. Key DC specifications include 2ppm INL, 1ppm easy evaluation of the LTC2499, LTC2497 or LTC2495. offset, 25ppm full-scale error and 10nV/C offset drift. In DC1012A may be connected directly to the target ap- the 6.8Hz/600nV mode, input normal mode rejection plications analog signals while using the DC590 USB RMS of 50Hz and 60Hz noise is better than 87dB. The LTC2499 serial controller board and QuikEval software to measure also includes an internal temperature sensor that is accurate performance. The exposed ground planes allow proper to 2C over the operating temperature range. grounding to prototype circuitry. After evaluating with LTCs software, the digital signals can be connected to DC1012A-B features the LTC2497 16-bit ADC that is the applications processor/controller for development pinout and software compatible with the LTC2499. of the serial interface. DC1012A-C features the LTC2495 16-bit ADC that also Design files for this circuit board are available at includes a PGA with a gain range from 1 to 256 and the DEMO MANUAL DC1012A QUICK START PROCEDURE ferential mode and 50Hz/60Hz rejection settings. Selecting Connect the DC1012A to a DC590 USB serial controller 2 speed located at the bottom of the strip-chart display using the supplied 14-conductor ribbon cable. Connect will double the data output rate at the expense of offset the DC590 to host PC with a standard USB A/B cable. accuracy (LTC2499 and LTC2495 only). Run the evaluation software supplied with the DC590 or downloaded from www.linear.com/software. The correct Tools are available for logging data, changing reference program will be loaded automatically. Click the COLLECT voltage, changing the number of points in the strip chart button to start reading the input voltage. The software and histogram, and changing the number of points aver- allows for selecting the input channel, single ended or dif- aged for the DVM display. HARDWARE SETUP Connection to DC590 Serial Controller Jumpers J2 is the power and digital interface connector. Connect to JP1, JP3 Select the source for REF+ and REF, re- a DC590 serial controller with the supplied 14-conductor spectively. REF+ can be 5.00V from the onboard LT1236 ribbon cable. Digital signals are also connected to through- reference (default) or supplied externally. REF can be hole test points on the circuit board. ground (0V, default) or supplied externally. JP2 Select source for analog COM input, either tied to Analog Connections ground or supplied externally to the COM turret post. Analog signal connections are made via the row of turret JP4 JP6 (CA0-CA2) Address select lines. Lines may posts along the edge of the board. Also, if you are connect- be 1, 0 or floating for a total of 27 different addresses. ing the board to an existing circuit, the exposed ground The default setting is all 1s. planes along the edges of the board may be used to form a solid connection between grounds. dc1012af 2