Overview
The DAC8742HPBSR is a versatile and low-power modem designed by Texas Instruments, compatible with HART, FOUNDATION Fieldbus, and PROFIBUS PA protocols. This device is tailored for industrial process control and automation applications, integrating all necessary circuitry for half-duplex operation in HART, FOUNDATION Fieldbus, and PROFIBUS PA modes. It supports both UART and SPI digital interfaces, making it highly flexible for various system configurations. The modem operates within a wide temperature range of -55°C to 125°C and features low quiescent current, enhancing its suitability for power-sensitive industrial environments.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| Supply Voltage (AVDD) | 2.7 | - | 5.5 | V |
| Supply Voltage (IOVDD) | 1.71 | - | 5.5 | V |
| Quiescent Current (FF/PA Mode, External Clock) | 160 | 220 | 330 | µA |
| Quiescent Current (FF/PA Mode, External Reference) | 175 | 200 | 320 | µA |
| Internal Reference Voltage | 1.47 | 1.5 | 1.53 | V |
| Operating Temperature Range | -55 | - | 125 | °C |
| Package Type | - | - | TQFP (32 pins) | - |
| Clock Frequency (HART Mode) | 3.6469 | 3.6864 | 3.7232 | MHz |
| Clock Frequency (FF/PA Mode) | 3.96 | 4 | 4.04 | MHz |
Key Features
- HART-compliant physical layer modem with 1200/2200 Hz FSK sinusoids and integrated RX demodulator and band-pass filter.
- FOUNDATION Fieldbus compatible H1 controller and medium attachment unit (MAU) with 31.25 kbit/s communication based on Manchester coded bus powered (MBP).
- PROFIBUS PA compatibility.
- Low quiescent current: 180 µA max at typical industrial operating temperature range (-40°C to 85°C).
- Integrated 1.5-V reference and flexible clocking options including internal oscillator, external crystal oscillator, and external CMOS clock.
- Digital interface support for both UART and SPI, with SPI interface including SDO pin for daisy-chain support and various interrupts.
- Reliability features such as CRC bit error checking and watchdog timer.
- Wide operating temperature range: -55°C to 125°C.
- Compact 5 mm x 5 mm TQFP package.
Applications
- Industrial process control and automation.
- PLC or DCS I/O modules.
- Field and sensor transmitters.
Q & A
- What protocols is the DAC8742HPBSR compatible with?
The DAC8742HPBSR is compatible with HART, FOUNDATION Fieldbus, and PROFIBUS PA protocols.
- What are the supported digital interfaces for the DAC8742HPBSR?
The device supports both UART and SPI digital interfaces.
- What is the operating temperature range of the DAC8742HPBSR?
The operating temperature range is -55°C to 125°C.
- What is the typical quiescent current of the DAC8742HPBSR in FF/PA mode with an external clock?
The typical quiescent current is 220 µA.
- Does the DAC8742HPBSR have integrated clocking options?
- What is the package type of the DAC8742HPBSR?
The device comes in a 5 mm x 5 mm TQFP package with 32 pins.
- What are some of the reliability features of the DAC8742HPBSR?
The device features CRC bit error checking and a watchdog timer for enhanced reliability.
- What are the typical applications of the DAC8742HPBSR?
Typical applications include industrial process control, PLC or DCS I/O modules, and field and sensor transmitters.
- How does the DAC8742HPBSR handle carrier detection in different modes?
In UART mode, the CD/IRQ pin indicates a valid carrier. In FF/PA mode, it indicates a valid carrier when not transmitting and jabber inhibitor trigger when transmitting. In SPI mode, it acts as a digital interrupt.
- What is the purpose of the internal 1.5-V reference in the DAC8742HPBSR?
The internal 1.5-V reference provides a stable voltage reference for the device, which can be enabled via the REF_EN pin.
