MTL5546 MTL Isolating Driver For 4–20mA HART® Valve Positioners With Line Fault Detection

The 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 smart 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 presetlevel.
See also common specification
• Number of channels
One
• Location of I/P converter
Zone 0, IIC, T4–6 hazardous area if suitably certified
Div. 1, Group A, hazardous location
• Working range
4 to 20mA
• Digital signal bandwidth
500Hz to 10kHz
• Maximum load resistance
800Ω (16V at 20mA)
• Minimum load resistance
90Ω (short-circuit detection at < 50Ω)
• Output resistance
> 1MΩ
• Under/over range capability
Under range = 1mA
Over range = 24mA (load ≤ 520Ω)
• Input and output circuit ripple
< 40µA peak-to-peak
• Transfer accuracy at 20°C
Better than 20µA
• Temperature drift
< 1.0µA/°C
• Input characteristics
< 6.0V with the field wiring intact
< 0.9mA with the field wiring open or short-circuit
• Response time
Settles within 200µA of final value within 100ms
• Communications supported
HART®
• LED indicator
Green: power indication
• Maximum current consumption (with 20mA signals into 250Ω load)
35mA at 24V dc
• Power dissipation within unit (with 20mA signals into 250Ω load)
0.8W at 24V
• Safety description
V_o=28V I_o=93mA P_o=651mW U_m = 253V rms or dc