P52
Chapter 1: Introduction
1-1
Chapter 1:
Introduction
1.1
Functional Description
Measuring 4.4 x 3.1 inches, the
P52
is an I/O expansion board designed for and driven by a Tern host
controller. A 16-bit external data bus is required to run the parallel ADC and DAC on the
P52
. Many
embedded applications demand high speed ADC and DAC with buffered operational amplifiers supporting
variable gains or offset for analog signals. The
P52
supports four 16-bit, parallel DACs (DAC8544)
buffered by 4 ops with gain=2 (hardware adjustable), providing ±5V analog output by default. A resistor
pot is used to adjust the DAC analog output offset. It also supports eight 16-bit parallel ADC inputs
(AD7655).
The
P52
can buffer PIOs with 16 sourcing drivers (UDN2982), or 14 sinking drivers (ULN2003). These
drivers can source or sink 350 mA at 50V per line to directly drive solenoids, relays, or lights. Eight high
isolation voltage photocouplers (PS2701, NEC) can be installed to provide optically isolators to PIOs. Two
quadrature decoders, (HCTL2020, Hewlett Packard) can be installed to interface incremental motion
encoders. In addition, 24 bi-directional TTL PPI I/Os (82C55) are software programmable and free to use.
100M BaseT
Ethernet
Serial Port 0
(Debug Port)
Serial Port 1
24 TTL I/O’s
2 Quadrature
Decoder inputs
+12V input
GND
8 16-bit ADC
inputs
4 16-bit DAC
ouputs
DAC offset-
adjusting POT
8 Opto-
coupler
inputs
14 High
Voltage
outputs
