The RCV420 is a precision current-loop receiver de-
signed to convert a 4鈥?0mA input signal into a 0鈥?V
output signal. As a monolithic circuit, it offers high
reliability at low cost. The circuit consists of a pre-
mium grade operational amplifier, an on-chip precision
resistor network, and a precision 10V reference. The
RCV420 features 0.1% overall conversion accuracy,
86dB CMR, and
鹵40V
common-mode input range.
The circuit introduces only a 1.5V drop at full scale,
which is useful in loops containing extra instrument
burdens or in intrinsically safe applications where
V+
16
RCV420
300k鈩?/div>
鈥揑n
1
R
S
75鈩?/div>
C
T
2
R
S
75鈩?/div>
+In
3
300k鈩?/div>
100k鈩?/div>
13
Rcv
Com
5
Ref
Com
1.01k鈩?/div>
+10V
Ref
99k鈩?/div>
V鈥?/div>
4
transmitter compliance voltage is at a premium. The
10V reference provides a precise 10V output with a
typical drift of 5ppm/擄C.
The RCV420 is completely self-contained and offers a
highly versatile function. No adjustments are needed
for gain, offset, or CMR. This provides three important
advantages over discrete, board-level designs: 1) lower
initial design cost, 2) lower manufacturing cost, and
3) easy, cost-effective field repair of a precision circuit.
Ref In
12
92k鈩?/div>
11.5k鈩?/div>
15 Rcv f
B
14 Rcv Out
11 Ref Out
10 Ref f
B
8
7
Ref Trim
Ref Noise Reduction
International Airport Industrial Park 鈥?Mailing Address: PO Box 11400, Tucson, AZ 85734 鈥?Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 鈥?Tel: (520) 746-1111 鈥?Twx: 910-952-1111