SBASAW9 December 2024 ADC168M102R-SEP
PRODUCTION DATA
For optimum performance, consider the physical layout of the ADC168M102R-SEP circuitry, particularly if the device is used at the maximum throughput rate. In this case, use a fixed phase relationship between CLOCK and CONVST.
Additionally, the high-performance SAR architecture is sensitive to glitches or sudden changes that occur just before latching the output of the internal analog comparator. The power supply, reference, ground connections, and digital inputs are potential sources of such interruptions. Therefore, when operating an n-bit SAR converter, there are n windows where large external transient voltages (glitches) potentially affect the conversion result. Such glitches originate from switching power supplies, nearby digital logic, or high-power devices. The degree of impact depends on the reference voltage, layout, and the actual timing of the external event.
With this possibility in mind, make sure power to the device is clean and well-bypassed. Place a 1µF ceramic bypass capacitor at each supply pin (connected to the corresponding ground pin) as close to the device as possible.
If the reference voltage is external, make sure the operational amplifier is able to drive the 22µF capacitor without oscillation. A series resistor between the driver output and the capacitor is potentially required. To minimize any code-dependent voltage drop on this path, use a small value for this resistor (10Ω max). TI's REF50xx family is able to directly drive such a capacitive load.