1B22AN Analog Devices Inc, 1B22AN Datasheet - Page 3
1B22AN
Manufacturer Part Number
1B22AN
Description
IC VOLTAGE CONVERTER PROG DIP
Manufacturer
Analog Devices Inc
Type
Voltage and Current Controllerr
Datasheet
1.1B22AN.pdf
(4 pages)
Specifications of 1B22AN
Rohs Status
RoHS non-compliant
Full Scale
±50ppm/°C
Linearity
±0.02%
Mounting Type
Through Hole
Package / Case
38-DIP (0.800", 20.32mm), 12 Leads
Ic Function
Voltage To Current Converter IC
Supply Voltage Range
14.25V To 15.75V, 14V To 30V
Operating Temperature Range
-40°C To +85°C
Digital Ic Case Style
DIP
No. Of Pins
12
Application
Multichannel process control, D⁄A converter—current loop interface, analog transmitters and controllers, remote data acquisition systems
Bandwidth
400 Hz
Converter Type
Voltage to Current
Current, Output
30 mA
Current, Output, Isolated
4 to 20 or 0 to 20 mA
Current, Quiescent Supply
±7.5 mA
Impedance, Input
50 Kiloohms
Package Type
38 Lead Plas Cust Hybrid
Standards
Meets IEEE STD 472: CMV Transient Protection (SWC)
Temperature, Operating, Maximum
85 °C
Temperature, Operating, Minimum
-40 °C
Voltage, Isolation
1500 V (RMS) (Max.)
Voltage, Operating
±15 V ±5%
Voltage, Protection
240 V (RMS)
Pin Programmable Inputs
0 V to +5 V or 0 V to +10 V
Pin Programmable Outputs
4 to 20 mA or 0 to 20 mA
High Cmv Isolation
1500 V RMS
Normal-mode Output Protection
240 V RMS
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Available stocks
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Quantity
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REV. B
INSIDE THE 1B22
The 1B22 produces an isolated 4 to 20 mA or 0 to 20 mA out-
put current which is proportional to the input voltage and
independent of the output load resistance (Figure 1). The input
stage is configured as an inverting amplifier with a resistor net-
work to provide pin-strappable input ranges of 0 V to +5 V and
0 V to +10 V and output ranges of 0 to 20 mA and 4 to 20 mA.
The conditioned signal is modulated to generate a square wave
that drives transformer T1. The peak-to-peak amplitude of the
signal is proportional to V
with a nominal output voltage of +6.4 V is used to develop a
4 mA offset for the 4 to 20 mA current loop output.
After passing through signal transformer T1, the amplitude
modulated signal is demodulated and filtered by a single pole
filter. This filtered output is the control signal for the voltage-
to-current converter stage. Timing information for the
demodulator is derived from the power transformer T2. The
1B22 outputs are protected from accidental shorts to ac line
voltages up to 240 V rms. Combined with 1500 V input to out-
put isolation, the 1B22 provides unbeatable protection against
transients, wiring errors and current loop short circuits to power
lines.
The dc-dc converter consists of a power driver, power trans-
former T2, a full wave rectifier and a filter. The dc-dc converter
provides the power for the output circuitry as well as the
isolated compliance voltage for the loop. This voltage is propor-
tional to V
supplies to power the input side circuitry and a +14 V to +30 V
supply for the dc-dc converter.
USING THE 1B22
Basic Interconnections: The 1B22 may be applied to achieve
rated performance as shown in Figure 2. For 0 V to 10 V signals
either IN1 or IN2 can be used for input; for 0 V to +5 V signals
jumper IN1 to IN2. Similarly, for 4 to 20 mA operation the
4 mA OFFSET node should be jumpered to the S. NODE,
while for 0 to 20 mA it should be tied to COM. Figure 3 shows
the functional diagram of the resistor network used in the 1B22.
For applications where a separate loop supply is not available,
the ± 15 V supplies can be used by connecting +15 V to V
(Pin 24) and COM to P.COM (Pin 25). For additional compli-
ance voltage, P.COM can be connected to –15 V to drive higher
loads.
Figure 1. 1B22 Functional Block Diagram
LOOP
on the input side. The 1B22 requires ± 15 V
IN
. An internal, high stability reference
LOOP
–3–
Optional Trim Adjustments: Figure 4 is an example of using
potentiometers for trimming gain and offset for a 0 V to +10 V
input and 4 to 20 mA output. The network for offset adjustment
keeps the resistors relatively small to minimize noise effects
while giving a sensitivity of ± 1% of span. The value of R1
should be 5 MΩ for the 0 V to +10 V range (for 0 V to +5 V
configurations, a 1.2 MΩ resistor should be used). For more
adjustment range, resistors smaller than 274 kΩ can be used.
50k
–15V
+15V
Figure 4. Optional Offset and Span Adjustment
V
274k
IN
1k
1k
Figure 3. Internal Resistor Network
20k
Figure 2. Basic Interconnections
SYNC
R1
+15V
COM
–15V
4mA
OFF
S. NODE
IN1
IN2
V
LOOP
RESISTOR
NETWORK
POWER
DRIVER
50k
P. COM
1B22
REF
RECTIFIER/
SUPPLY
LOOP
1B22
PROT
OUT
LO
OUT
HI