MTL5544A/AS CURRENT REPEATER 4/20MA PASSIVE I/P FOR HART® TRANSMITTERS

MTL5544A/AS current repeater 4/20mA passive i/p for HART® transmitters

MTL5544A provides an input for separately powered 4/20mA transmitters and also allows bi–directional transmission of HART communication signals superimposed on the 4/20mA loop current, so that the transmitter can be interrogated either from the operator station or by a hand-held communicator (HHC). Alternatively, MTL5544AS acts as a current sink for a safe-area connection rather than driving a current into the load.

SPECIFICATION

See also common specification

Number of channels

Two

Location of transmitter

Zone 0, IIC, T4–6 hazardous area if suitably certified

Div.1, Group A, hazardous location

Hazardous area input

Signal range: 4 to 20mA

Under/over-range: 1.0 to 21.5mA

Input impedance for HART signals

at terminals 1, 2 and 4, 5: > 230Ω

Maximum input volt drop

at terminals 1, 2 and 4, 5: < 6.6V

i.e. a transmitter load of 330Ω at 20mA

Safe-area output

Signal range: 4 to 20mA

Under/over-range: 1.0 to 21.5mA

Safe-area load resistance (MTL5544A)

Conventional transmitters: 0 to 360Ω

Smart transmitters: 250Ω ±10%

Safe-area load (MTL5544AS)

Current sink: 600Ω max.

Maximum voltage source: 24V DC

Safe-area circuit output resistance: > 1MΩ

Safe–area circuit ripple

< 50μA peak-to-peak up to 80kHz

Transfer accuracy at 20°C

Better than 20μA

Temperature drift

< 1μA/°C

Response time

Settles within 200μA of final value after 20ms

Communications supported

HART