DEMO MANUAL DC2326A LTC2345 16-/18-Bit, Octal 200ksps, SAR ADC Description Demonstration circuit 2326A shows the proper way to drive demonstrate DC performance such as peak-to-peak noise the LTC 2345 ADC. The LTC2345 is a low noise, high speed, and DC linearity. Use the DC890 if precise sampling rates simultaneous sampling 16-/18-bit successive approximation are required or to demonstrate AC performance such as register (SAR) ADC. The LTC2345 has a flexible SoftSpan SNR, THD, SINAD and SFDR. The DC2326A is intended interface that allows conversion-by-conversion control of to demonstrate recommended grounding, component the input voltage span on a per-channel basis. An internal placement and selection, routing and bypassing for this 2.048V reference and 2 buffer simplify basic operation ADC. A suggested driver circuit for the analog inputs is while an external reference can be used to increase the also presented. input range and the SNR of the ADC. Design files for this circuit board including the schematic, The DC2326A demonstrates the DC and AC performance of layout and BOM are available at the LTC2345 in conjunction with the DC590/DC2026 and DEMO MANUAL DC2326A Dc890 Quick s p D Check to make sure that all jumpers are set to their default Run the PScope software (Pscope.exe version K82 or settings as described in the DC2326A Jumpers section of later) which can be downloaded from www.linear.com/ this manual. The default connections configure the ADC to designtools/software. use the onboard reference and regulators to generate all Complete software documentation is available from the the required bias voltages. The analog inputs by default are Help menu. Updates can be downloaded from the Tools DC coupled. Connect the DC2326A to a DC890 USB High menu. Check for updates periodically as new features Speed Data Collection Board using connector P1. Then, may be added. connect the DC890 to a host PC with a standard USB A/B The PScope software should recognize the DC2326A and cable. Apply 9V to the indicated terminals. Then apply configure itself automatically. a low jitter signal source to J5 and J6. Use J7 to route the signal sources of J5 and J6 to the desired AIN0-AIN7 Click the Collect button (See Figure 3) to begin acquiring inputs. Observe the recommended input voltage range data. The Collect button then changes to Pause, which for each analog input. Connect a low jitter 2.5V sine P-P can be clicked to stop data acquisition. wave or square wave to connector J1. See the Assembly Options table for the appropriate clock frequency. Note that J1 has a 50 termination resistor to ground. Dc590/ Dc2026 Quick s p D IMPORTANT To avoid damage to the DC2326A, make and J6. Use J7 to route the signal sources of J5 and J6 sure that VCCIO (JP6 of the DC590, JP3 of the DC2026) to the desired AIN0-AIN7 inputs. No Clock is required on of the DC590/DC2026 is set to 3.3V before connecting J1 when using the DC590/DC2026. The clock signal is the DC590/DC2026 to the DC2326A. provided by the DC590/DC2026. To use the DC590/DC2026 with the DC2326A, it is necessary Run the QuikEval software (quikeval.exe version K103 or to apply 9V and ground to the 9V and GND terminals of later) which is available from www.linear.com/designtools/ the DC2326A. Connect the DC590/DC2026 to a host PC software. The correct control panel will be loaded auto- with a standard USB A/B cable. Connect the DC2326A to matically. Click the COLLECT button (Figure 6) to begin a DC590/DC2026 USB serial controller using the supplied reading the ADC. 14-conductor ribbon cable. Apply a signal source to J5 dc2326af 2 ure roce tart ure roce tart