DRC1746_15 Datasheet, PDF (7/8 Pages) Analog Devices – HIGH POWER OUTPUT HYBRID DIGITAL TO SYNCHRO RESOLVER CONVERTERS

ANALOGDEVICES fAX-ON-DEMAND HOTLINE - Page 16
DRC1745/DRC1746
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Figure 8. DRC7745/DRC1746Output Stage Showing
TransZorb Protection
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NOTE, FO" SYNC~O OUTPUT uCT" MUST BE CONNECTED TO "TC",
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Figure 9 showsthe nature of transient wavefonnswhere by the
Figure 10. Connecting the DRC7745 to the STM1680 and
OBSOLETE very large transient voltage generated by the inductive load is
limited to a safe clamp level when it is applied to the output
stage.
OUTPLff CURREtolT
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OUTPUT VOLTAGE
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Figure 9. Transient Waveforms and TransZorb Clamping
STM1683 Transformers
RESISTIVE INPUT SCALING
The analog reference input can be externally resistively scaled to
cater for a wide range of voltage both when used with or without
the reference transformer, STM1680/STMl660.
When the converters are used with the STM1680/STMl660
transfonner, a resistance of value 3kfl per extra volt required
should be inserted in the Am line. Care should be taken to
ensure that the voltage on the analog input (Am, ALo) is 3.4
volts rms in order to provide a full scale analog output. The
maximum output voltage of the converter is proportional to the
inpUt voltage (gain of 2) and therefore the resistor tolerance
should be chosen so that the correct voltage appears across the
Am, ALo pins. Note that the input to the reference transformer
should not exceed the rated max.
Note that the best dc output offset performance is achieved
when the STM1680/STMl660 transformer is used. However the
In addition, there arc conventional diode clamps on the ::!1: 5V(P)
power supplies.
use of resistive scaling can never cause an additional offset of
greater than 6.5mV (max), 2.6mV (typ).
OUTPUT AND REFERENCE TRANSFORMERS
A set of low profIJe (0.4" high) reference and output transfonners
(which are capable of handling the full drive capability of the
DRC1745 and DRC1746 over a frequency range of 360Hz to
2.6kHz) are available in order to accept the standard voltage
OTHER PRODUCTS
We manufacture a wide range of hybrid and modular circuits
for processing synchro and resolver information. Please ask for
our comprehensive literature.
formats of synchros and resolvers.
The reference transfonner, STM1680, can accept voltages of
11.8 volts, 26 volts or 115 volts depending on the option and its
output is 3.4 volts nns which is suitable for connecting to Am
and Aw on the converter.
The output transfonner pair, STM1683, accepts the 6.8 volts
rIDSoutput of the converter and provides a synchro or resolver
format depending on the option.
Note: For resolver option for the STM1683 transformer, part
number is RTM1683.
The pin out and dimensions of the STM1680 and STM1683 are
shown on the next page, and the connection to the converter in
Figure 10.
Note: For operation over the frequency range 47Hz to 440Hz a
similar set of transformers are available (1.0" profIle height).
Part numbers are STMl660 (reference transformer) and
STMl663 (output transformer).
REV. A
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