Specifications

20 Control and Automation Solutions Guide
Save Space in Low-Power Process-Control
Equipment with a Single-Chip HART Modem
DS8500
The DS8500 is a single-chip modem with HART capabilities that satisfy the
HART physical-layer requirements. This device operates in half-duplex fashion,
and integrates the modulation and demodulation of the 1200Hz/2200Hz
FSK signal while consuming very low power. It only needs a few external
components because of the integrated digital-signal processing.
Benefits
• Highly integrated HART modem
solution saves space
◦ Fewest external components due to
the built-in digital-receive filter
◦ 5mm x 5mm x 0.8mm, 20-pin TQFN
package
• Robust signaling reduces data errors
due to lowest harmonic distortion
◦ Sinusoidal output signal
CRYSTAL
OSCILLATOR
CLOCK
GENERATOR
XTAL1
RST AVDDAGNDDGNDDVDD
POWER
MONITOR
XTAL2
Rx
DEMODULATOR
DIGITAL
FILTER
SAMPLE/HOLD
ADC
OCD
D_OUT
Tx
MODULATOR
RTS
D_IN
XCEN
FSK_IN
REF
DAC FSK_OUT
V
REF
1.23V
DS8500
Block diagram of the DS8500.