MTL4549 - MTL 4500 Intrinsically Safe Isolators

MTL4549/C/Y - MTL5549/Y ISOLATING DRIVER two-channel, for 4–20mA, HART® valve positioners with line fault detection The MTLx549 accepts 4/20mA floating signals from safe-area controllers to drive 2 current/pressure converters (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. 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 MTL4549C and MTLx549Y are very similar to the MTLx549 except that they provide open circuit detection only (i.e. no short-circuit detection).

• Number of channels
     Two
• 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
• Communications supported
     HART
• Transfer accuracy at 20°C
     Better than 20µA
• Temperature drift
     < 1.0µA/°C
• Input characteristics
     Normal :< 6.0V
     Open-circuit: < 0.9mA
     Short-circuit :< 0.9mA
• Response time
     Settles within 200µA of final value within 100ms
• LED indicator
     Green: power indication
• Maximum current consumption (with 20mA signals into 250Ω load)
     70mA at 24V dc
• Power dissipation within unit (with 20mA signals into 250Ω load)
     1.6W at 24V
• Safety description (each channel)
     U_o=28V I_o=93mA P_o=0.65W U_m = 253V rms or dc