12-bit SAR at 250kSPS — what the throughput means for the signal chain
The LTC2361ITS8#TRPBF: The LTC2361 is a 12-bit successive-approximation-register ADC sampling at 250kSPS. At that conversion rate each sample window is 4 µs — the input must settle to 12-bit accuracy within that window, which sets a practical limit on the source impedance and the anti-aliasing filter's RC time constant. A 1 kΩ source driving a 10 nF cap crosses the 4 µs mark; anything slower and the last few LSBs start to wander. For a prototype run or a low-volume build this is fine; for a high-volume pick-and-place line you will want the reel option — the same die, different ordering code.
Active production — no end-of-life clock ticking
That means the die is still in the fab queue and the package assembly line is running.
Peer comparison — resolution and speed trade-offs
The AD7661ACPRL is a 16-bit SAR — four extra bits of resolution but a different pinout and control interface. If your design already has the layout and firmware for the AD7661, the LTC2361 does not drop in without a board spin. The AD7478AWARMZ-RL is an 8-bit part sampling at 1 MSPS — four times the speed but only 8 bits. For a 12-bit, 250kSPS slot, the LTC2361 sits between these two: more resolution than the 8-bit part, faster conversion than the 16-bit part, and a simpler serial interface that does not need the parallel bus of the AD7664.