Overview
The DAC8740HRGER, produced by Texas Instruments, is a specialized integrated circuit designed for industrial process control and automation. It is part of the DAC874xH family, which includes HART®, FOUNDATION Fieldbus™, and PROFIBUS PA compatible low-power modems. These modems are engineered to operate in various industrial communication protocols with minimal external components. The DAC8740H specifically features a UART digital interface, making it suitable for applications requiring reliable and efficient communication in harsh industrial environments.
Key Specifications
| Parameter | Description | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Digital Interface | UART | ||||
| Power Supply (AVDD) | 2.7 | 5.5 | V | ||
| Power Supply (IOVDD) | 1.71 | 5.5 | V | ||
| Operating Temperature | -40 | 105 | ℃ | ||
| Quiescent Current (HART Mode, External Clock) | Demodulator Active | 110 | 150 | µA | |
| Quiescent Current (HART Mode, External Clock) | Modulator Active | 160 | 180 | µA | |
| Internal Reference Voltage | 1.47 | 1.5 | 1.53 | V | |
| HART Modem Input Voltage Range | 0 | 1.5 | VPP | ||
| HART Modem Output Voltage | 450 | 460 | 480 | mVPP |
Key Features
- HART Compliance: The DAC8740H is HART-compliant, supporting 1200-Hz and 2200-Hz HART FSK sinusoids with integrated RX demodulator and band-pass filter.
- FOUNDATION Fieldbus Compatibility: It operates as a half-duplex 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: Compatible with PROFIBUS PA protocols.
- Low Quiescent Current: Maximum quiescent current of 180 µA at typical industrial operating temperatures.
- Integrated Voltage Reference: Features an integrated 1.5-V reference.
- Flexible Clocking Options: Supports internal oscillator, external crystal oscillator, and external CMOS clock.
- Digital Interface: Uses a UART interface for data transfer.
- Reliability Features: Includes CRC bit error checking and a watchdog timer (for DAC8741H model).
- Wide Operating Temperature Range: Operates from -55°C to +125°C.
- Compact Package: Available in a 4-mm × 4-mm QFN package.
Applications
- Industrial Process Control and Automation: Ideal for use in industrial process control systems and automation environments.
- PLC or DCS I/O Modules: Suitable for use in programmable logic controllers (PLCs) and distributed control systems (DCS) I/O modules.
- Field and Sensor Transmitters: Used in field and sensor transmitters where reliable communication is crucial.
Q & A
- What is the primary function of the DAC8740H?
The DAC8740H is a low-power modem designed for HART, FOUNDATION Fieldbus, and PROFIBUS PA communication protocols in industrial process control and automation.
- What digital interface does the DAC8740H use?
The DAC8740H uses a UART (Universal Asynchronous Receiver-Transmitter) digital interface.
- What are the operating temperature ranges for the DAC8740H?
The DAC8740H operates from -55°C to +125°C.
- What is the quiescent current of the DAC8740H in HART mode with an external clock?
The quiescent current in HART mode with an external clock is typically 150 µA for the demodulator active and 180 µA for the modulator active.
- Is the DAC8740H compatible with FOUNDATION Fieldbus?
Yes, the DAC8740H is compatible with FOUNDATION Fieldbus and operates as a half-duplex H1 controller and medium attachment unit (MAU).
- What is the package type of the DAC8740H?
The DAC8740H is available in a 4-mm × 4-mm QFN package.
- Does the DAC8740H have integrated voltage reference?
Yes, the DAC8740H features an integrated 1.5-V reference.
- What are the clocking options available for the DAC8740H?
The DAC8740H supports internal oscillator, external crystal oscillator, and external CMOS clock.
- What reliability features does the DAC8740H include?
The DAC8740H includes CRC bit error checking. Note that the watchdog timer is available only in the DAC8741H model.
- In what types of applications is the DAC8740H commonly used?
The DAC8740H is commonly used in industrial process control and automation, PLC or DCS I/O modules, and field and sensor transmitters.
