Specifications

22 Maxim Industrial Solutions
Programmable logic controllers (PLCs)
Analog output functions
Benefits
• Higher density due to low-power draw
– 285μA (max) current consumption
• Saves space
– Fewest external components due to the
built-in digital-receive filter
– 20-pin, 5mm x 5mm x 0.8mm TQFN
package
• Easily available crystal
– Uses a standard 3.6864MHz clock input
• Robust signaling due to lowest
harmonic distortion
– Sinusoidal output signal
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 demodu-
lation 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.
Save space in low-power process-control equipment with a single-chip HART modem
Block diagram of the DS8500.
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