By Alix Paultre, contributing editor

MAX12900 ultra-low-power, highly integrated 4–20-mA sensor transmitter from
Maxim Integrated Products has a 10-ppm/°C voltage reference for up to 3.5 times
lower drift compared to traditional solutions. The small footprint (5 x 5-mm
package size) of the MAX12900 integrates 10 optimized building blocks that
result in significant space savings of 20% to 50% versus traditional 4–20-mA
sensor transmitter implementations.


The addition of an integrated high-voltage LDO
and power sequencing capability simplifies the power up of the 4–20-mA sensor
transmitter. Its reduced current consumption for low power requires just 250 uA
of current maximum, enabling up to 50% power savings compared to traditional
solutions. The new MAX12900 solution reduces implementation complexity,
generating system cost savings by converting pulse-width modulation data from a
microcontroller into current over a 4–20-mA loop with two, three, or four wire
configurations. The MAX12900 is available in a 32-pin TQFN package and operates
over a wide industrial temperature range of –40°C to 125°C.