MTL5546/MTL5546Y - Isolating Driver
Single channel, for 4/20mA HART® valve positioners with line-fault detection
MTL5546 accepts a 4/20mA floating signal from a safe-area controller to drive a current/pressure converter (or any other load up to 800Ω) in a hazardous area. For HART valve positioners, the module also permits bi-directional transmission of digital communication signals so that the device can be interrogated either from the operator station or by a hand-held communicator. Process controllers with a readback facility can detect open or short circuits in the field wiring: if these occur, the current taken into the terminals drops to a preset level. The MTL5546Y is very similar to the MTL5546 except that it provides open circuit detection only (i.e. no short-circuit detection).