DS8500 MAXIM | Alldatasheet
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 6
Technical content
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 DS8500 HART Modem THIN QFN (5mm × 5mm) TOP VIEW DVDD RST OCD DVDD FSK_IN FSK_OUT AVDD AGND DGND 15 14 12 11 D_OUT D_IN DGND XTAL2 XTAL1 RTS DGND REF DGND 16 10 XCENDGND DS8500 + *EP *EXPOSED PAD. Pin Configuration
Ordering Information
Rev 0; 10/08 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. PART TEMP RANGE PIN-PACKAGE DS8500-JND+ -40 °C to +85°C 20 TQFN-EP* +Denotes a lead-free/RoHS-compliant package. *EP = Exposed pad.
RECOMMENDED DC OPERATING CONDITIONS (VDVDD = VAVDD = 2.7V to 3.6V, TA = -40°C to +85°C.) (Note 1) Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 1: Specifications to -40°C are guaranteed by design and are not production tested. Note 2: Active currents are measured when the device is driven by an external clock XCEN = 1 condition. Note 3: Guaranteed by design and not production tested. Note 4: Accuracy is guaranteed based on the external crystal or clock provided. Voltage Range on All Pins (including AVDD, Voltage Range on Any Pin Relative to J-STD-020 Specification. PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Digital Supply Voltage V DVDD 2.7 3.6 V Analog Supply Voltage V AVDD V AVDD = VDVDD 2.7 3.6 V Ground GND AGND = DGND 0 0 V Digital Power-Fail Reset Voltage V RST Monitors V DVDD 2.59 2.64 2.69 V Active Current I DD V AVDD = VDVDD = 2.7V (Note 2) 285 μA Input Low Voltage V IL DGND 0.30 x VDVDD V Input High Voltage V IL 0.75 x VDVDD V DVDD V Output Low Voltage V OL I OL = 4mA DGND 0.4 V Output High Voltage V OH I OH = -4mA 0.8 x VDVDD V I/O Pin Capacitance C IO Guaranteed by design (Note 3) 15 pF RST Pullup Resistance R RST 19 45 k Input Leakage Current XTAL, RST IILRX -30 +30 μA Input Leakage Current All Other Pins IIL -2 +2 μA Input Low Current for RST I IL1 V IN = 0.4V 170 μA CLOCK SOURCE External Clock Frequency f HFIN -1% 3.6864 +1% MHz VOLTAGE REFERENCE Internal Reference Voltage V REF 1.23 V FSK INPUT Input Voltage Range at FSK_IN 0 V REF V FSK OUTPUT Output Voltage at FSK_OUT V OUT AC-coupled max 30k load 400 500 600 mV P-P For a mark -1% 1200 +1% Frequency of FSK_OUT (Note 4) For a space -1% 2200 +1% kHz
1, 2 DVDD Digital Supply Voltage 3, 9, 16, 17, 18 DGND Digital Ground 4 RST Active-Low Reset, Digital Input/Output. This pin includes an internal pullup resistor and is driven low as an output when an internal reset condition occurs.
5 OCD
Carrier Detect, Digital Output. A logic-high indicates a valid carrier detection on FSK_IN. OCD = 1 when FSK_IN amplitude is greater than 120mV P-P. OCD = 0 when FSK_IN amplitude is less than 80mV P-P. 6 RTS Request to Send, Digital Input. When set high, the device is put into the demodulator mode. A logic-low puts the device into modulator mode. 7 XTAL1 Crystal Pin or Input for External Clock at 3.6864MHz
8 XTAL2 Crystal Pin or Output of the Crystal Amplifier
10 XCEN
External Clock Enable, Digital Input. When set high, this pin allows the user to drive an external clock signal through XTAL1. When in this mode, XTAL2 should be left unconnected. An external crystal must be connected between XTAL1 and XTAL2 when set low.
11 AVDD Analog Supply Voltage
12 FSK_OUT FSK Out, Analog Output. Output of the modulator. Provides a phase-continuous, FSK-modulated output signal (1200Hz and 2200Hz output frequencies) to the 4mA to 20mA current loop interface circuit. 13 REF Reference, Analog Output. The internal voltage reference is provided as output. This pin must be connected to a 0.1μF capacitor. 14 FSK_IN FSK In, Analog Input. Input for the FSK-modulated HART receive signal from the 4mA to 20mA current loop interface circuit.
15 AGND Analog Ground
19 D_OUT Digital Data Out, Digital Output. Output from the demodulator. 20 D_IN Digital Data In, Digital Input. Input to the modulator. Block Diagram DS8500 CRYSTAL OSCILLATOR CLOCK GENERATOR XTAL1 RST AVDD AGNDDGNDDVDD POWER MONITORXTAL2 Rx DEMODULATOR DIGITAL FILTER SAMPLE/HOLD ADC OCD D_OUT Tx MODULATOR RTS D_IN XCEN FSK_IN REF DAC FSK_OUT VREF 1.23V
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circu it patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. DS8500 CRYSTAL OSCILLATOR CLOCK GENERATOR XTAL1 RST AVDD POWER SUPPLY 2.7V TO 3.6V AGNDDGNDDVDD POWER MONITOR XTAL2 Rx DEMODULATOR DIGITAL FILTER SAMPLE/HOLD ADC OCD D_OUT Tx MODULATOR RTS D_IN XCEN MICROCONTROLLER FSK_IN REF DAC FSK_OUT VREF 1.23V 3.6864MHz 3.6864MHz CRYSTAL HART IN 4mA TO 20mA DAC OUTPUT HART AND 4mA TO 20mA OUT Figure 4. Typical Application Circuit PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
20 TQFN T2055+3 21-0140
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.