The maximum sampling rate of the LTC2451 is 15ksps (kilo-samples per second) for a single channel, and 7.5ksps for multiple channels.
To ensure accurate conversions, make sure to follow proper PCB layout guidelines, use a low-noise power supply, and minimize digital noise coupling to the analog inputs.
Yes, the LTC2451 can be used with an external reference voltage. The REF pin can be connected to an external reference voltage source, and the internal reference voltage can be disabled by connecting the REFEN pin to GND.
The power consumption of the LTC2451 depends on the operating mode and the sampling rate. In normal mode, the typical power consumption is 1.5mA at 5V supply voltage, and in shutdown mode, the typical power consumption is 1μA.
The LTC2451 can be interfaced with a microcontroller using a 3-wire SPI interface. The microcontroller can send commands to the LTC2451 to start conversions, read data, and configure the device.