DC2412A-A Analog Devices

DEMO MANUAL DC2412A LTC2335 16-/18-Bit, Octal 1Msps, SAR ADC DESCRIPTION Demonstration circuit 2412A shows the proper way to demonstrate DC performance such as peak-to-peak noise drive the LTC 2335 ADC. The LTC2335 is a low noise, high and DC linearity. Use the DC890 if precise sampling rates speed, 8-channel 16-/18-bit successive approximation are required or to demonstrate AC performance such as register (SAR) ADC. The LTC2335 has a flexible SoftSpan SNR, THD, SINAD and SFDR. The DC2412 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 schematics, The DC2412 demonstrates the DC and AC performance of layout and BOM are available at DEMO MANUAL DC2412A BOARD PHOTO 16V GND +16V 10.24V DEFAULT DC890 INPUT LEVELS 10.24V DC2412A F01 DC590 OR DC2026 CLK 100MHz MAX 2.5V P-P Figure 1. DC2412A Connection Diagram DC890 QUICK START PROCEDURE Check to make sure that all switches and jumpers are set to a host PC with a standard USB A/B cable. Apply 16V their default settings as described in the DC2412A Jumpers to the indicated terminals. Then apply a low jitter signal and Connectors section of this manual. The default con- source to J5 and J6. Use J7 to route the signal sources nections configure the ADC to use the onboard reference of J5 and J6 to the desired IN0 to IN7 inputs. Observe the and regulators to generate all the required bias voltages. recommended input voltage range for each analog input. The analog inputs by default are DC coupled. Connect the Connect a low jitter 2.5V sine wave or square wave to P-P DC2412A to a DC890 USB High Speed Data Collection connector J1. See DC2412 Assembly Options table for Board using connector P1. Then, connect the DC890 to the appropriate clock frequency. Note that J1 has a 50 termination resistor to ground. dc2412af 2