MTL5546
ISOLATING DRIVER
for 4–20mA smart 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 preset level.
SPECIFICATIONSee 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
Vo=28V Io=93mA Po=651mW Um = 253V rms or dc
Terminal Function
1 Output –ve
2 Output +ve
11 Input –ve
12 Input +ve
13 Supply –ve
14 Supply +ve
