DAC8740H Datasheet, PDF (1/8 Pages) Texas Instruments – HART and FOUNDATION Fieldbus / PROFIBUS PA Modems

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DAC8740H, DAC8741H, DAC8742H
SBAS862 – JUNE 2017
DAC874xH, HART and FOUNDATION Fieldbus / PROFIBUS PA Modems
1 Features
•1 HART-Compliant Physical Layer Modem
– 1200/2200 Hz HART FSK Sinusoids
– Register Programmable Amplitude of TX
Signals
(DAC8741H / DAC8742H only)
– Integrated RX Demodulator and Band-Pass
Filter with Minimal External Components
• Foundation Fieldbus Compliant H1 Controller and
Medium Attachment Unit (MAU)
– 31.25 kbit/s Communication Based on
Manchester Coded Bus Powered (MBP)
– Integrated Manchester Encoder and Decoder
– Compliant with PROFIBUS PA
• Low Quiescent Current: 200 uA Max
• Integrated 1.5 V Reference
• Flexible Clocking Options
– External Crystal Oscillator
– External CMOS Clock
• Digital Interface
– DAC8740H: UART
– DAC8741H: SPI
– DAC8742H: UART and SPI
• Reliability: CRC Bit Error Checking, Watchdog
Timer (DAC8741H and DAC8742H only)
• Wide Operating Temperature: –55°C to 125°C
• 4 mm x 4 mm QFN and 5 mm x 5 mm TQFP
Packages
2 Applications
• Industrial Process Control and Automation
• PLC or DCS I/O Modules
• Field and Sensor Transmitters
3 Description
The DAC8740H, DAC8741H, and DAC8742H are
HART^®, FOUNDATION Fieldbus™, and PROFIBUS
PA compliant low power modems designed for
industrial process control and industrial automation
applications.
In HART mode, the DAC874xH integrates all of the
required circuitry to operate as half-duplex HART
physical layer modems, in either slave or master
configurations with minimal external components for
filtering. In FOUNDATION Fieldbus mode, the
DAC874xH integrates all of the required circuitry to
operate as half-duplex FOUNDATION Fieldbus
compliant H1 Controllers and MAUs.
The HART, FOUNDATION Fieldbus, or PROFIBUS
PA, data stream can be transferred from the
microcontroller through either a UART interface or an
integrated FIFO accessed by a SPI interface. The
SPI interface includes an SDO pin for daisy-chain
support, various interrupts, and other extended
features.
The devices operate from a supply of 2.7V to 5.5V
while consuming only 200 uA, making them an
excellent choice for loop-powered or 2-wire
applications. They operate from –55°C to 125°C and
are available in 24-lead VQFN and 32-lead TQFP
packages.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
DAC8740H
VQFN (24)
4 mm × 4 mm
DAC8741H
VQFN (24)
4 mm × 4 mm
DAC8742H
TQFP (32)
5 mm × 5 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
IOVDD CLK_CFG0 CLK_CFG1 CLKO XEN X1 X2
REF_EN REF REG_CAP AVDD
RST
CD / IRQ
UART_IN / CS
DUPLEX / SDI
UART_OUT / SDO
UART_RTS / SCLK
IF_SEL
Clock
Generator
Precision
Oscillator
Voltage
Reference
MUX
HART
PA/FF
Transmit
Modulator
DAC
Receive
Modulator
Carrier
Detect
Buffer
Bandpass
Filter
MOD_OUT
MOD_INF
MOD_IN
DGND
1
BPFEN
GND
Copyright © 2017, Texas Instruments Incorporated
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. ADVANCE INFORMATION for pre-production products; subject to
change without notice.