1B22AN Analog Devices Inc, 1B22AN Datasheet - Page 4

• Manufacturer Part Number: 1B22AN
• Description: IC VOLTAGE CONVERTER PROG DIP
• Manufacturer: Analog Devices Inc
• Type: Voltage and Current Controllerr

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

Synchronizing Multiple 1B22s: In applications where mul-
tiple 1B22s are used in close proximity, radiated individual
oscillator frequencies may cause “beat frequency” related out-
put errors. These errors can be eliminated by driving the SYNC
pins of all the units with a 40 kHz clock circuit at 50% duty
cycle (Figure 5). The SYNC input typically has an input imped-
ance of 150 kΩ 180 pF.
Loop Supply Requirements: The 1B22 design allows flexible
loop supply options. The loop supply voltage required for any
value of load resistance can be calculated from the following
equation:
This value allows for approximately 10% overrange capability.
The graph in Figure 6 shows the relationship between supply
voltage and load resistance.
1B22
Figure 5. Multiple 1B22s’ Synchronization
Figure 6. Loop Supply vs. Load
V
LOOP
=
2R
L
106
+ 780
–4–
APPLICATIONS
Isolated D/A Converter: The 1B22 offers total ground isola-
tion and protection from high voltage transients in interfacing
D/A converters to standard 4 to 20 mA current loops. The D/A
converter, such as the Analog Devices’ 12-bit AD7245
DACPORT®, should be connected for operation on the unipo-
lar 0 V to +10 V output range. This is shown in Figure 7.
Pressure Transmitter: In Figure 8, the 1B22 is used in a
pressure transmitter application to provide complete input-
output isolation and avoid signal errors due to ground loop cur-
rents. The process pressure is monitored with a strain gage type
pressure transducer interfaced by the Analog Devices’ 1B32
transducer signal conditioner. The high level voltage output of
the 1B32 is converted to the isolated 4 to 20 mA current for
transmission to a remote recorder or indicator.
DACPORT is a registered trademark of Analog Devices, Inc.
Figure 7. D/A Converter–Isolated 4-20 mA Interface
Figure 8. Isolated Pressure Transmitter
REV. B