DS8500_09 Datasheet, PDF (1/7 Pages) Maxim Integrated Products – HART Modem

Rev 1; 2/09
HART Modem
General Description
The DS8500 is a single-chip modem with Highway
Addressable Remote Transducer (HART) capabilities
and satisfies the HART physical layer requirements.
The device integrates the modulation and demodulation
of the 1200Hz/2200Hz FSK signal, has very low power
consumption, and needs only a few external compo-
nents due to the integrated digital signal processing.
The input signal is sampled by an analog-to-digital con-
verter (ADC), followed by a digital filter/demodulator.
This architecture ensures reliable signal detection in
noisy environments. The output digital-to-analog con-
verter (DAC) generates a sine wave and provides a
clean signal with phase-continuous switching between
1200Hz and 2200Hz. Low power is achieved by dis-
abling the receive circuits during transmit and vice
versa. The DS8500 is ideal for low-power process con-
trol transmitters.
Applications
4–20mA Loop-Powered Transmitters for
Temperature, Pressure, Flow, and Level
Measurement
HART Multiplexers
HART Modem Interface Connectivity
Pin Configuration
Features
♦ Single-Chip, Half-Duplex, 1200bps FSK
Modulation and Demodulation
♦ Digital Signal Processing Provides Reliable Input
Signal Detection in Noisy Conditions
♦ Sinusoidal Output Signal with Lowest Harmonic
Distortion
♦ Few External Components Enable a Space-Saving
Solution
♦ Standard Component 3.6864MHz Crystal
♦ Complies to HART Physical Layer Requirements
♦ 2.7V to 3.6V Operating Voltage
♦ 285µA (max) Current Consumption
♦ Space-Saving, 5mm x 5mm x 0.8mm, 20-Pin TQFN
Package
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
DS8500-JND+
-40°C to +85°C
20 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
TOP VIEW
15 14 13 12 11
DGND 16
DGND 17
DGND 18
D_OUT 19
D_IN 20
+
DS8500
*EP
10 XCEN
9 DGND
8 XTAL2
7 XTAL1
6 RTS
12345
*EXPOSED PAD.
THIN QFN
(5mm × 5mm)
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.