Overview
The A5191HRT, specifically the A5191HRTPG-XTP model, is a single-chip, CMOS modem designed for use in Highway Addressable Remote Transducer (HART) field instruments and masters. This modem, produced by onsemi, integrates all the necessary functions to satisfy HART physical layer requirements, including modulation, demodulation, receive filtering, carrier detection, and transmit-signal shaping. It utilizes phase continuous frequency shift keying (FSK) and operates within a standard 11-bit UART frame with a communication speed of 1200 baud.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| Ambient Temperature (TA) | -40 | 85 | °C | |
| Storage Temperature (TS) | -55 | 150 | °C | |
| Junction Temperature (TJ) | -40 | 85 | °C | |
| Supply Voltage (VDD) | -0.3 | 6.0 | V | |
| DC Input, Output (VIN, VOUT) | -0.3 | VDD + 0.3 | V | |
| Modem Characteristics - Demodulator Jitter | See Table 4 for detailed conditions | |||
| External Clock Frequency | 456.2 | 460.8 | 465.4 | kHz |
| Carrier Detect Output Rise/Fall Time | 20 | ns | ||
| Receive Digital Output Rise/Fall Time | 20 | ns |
Key Features
- Single-chip CMOS modem for HART field instruments and masters.
- Phase continuous frequency shift keying (FSK) modulation and demodulation.
- Integrated receive filtering, carrier detection, and transmit-signal shaping.
- Operates within a standard 11-bit UART frame with 1200 baud communication speed.
- Supports external clock or internal oscillator with a 460.8 kHz ceramic resonator.
- Requires minimal external passive components.
- Available in 28-pin PLCC, 32-pin QFN, and 32-pin LQFP packages.
- RoHS compliant and green packaging options.
- Analog and digital supply voltages with separate grounds for improved noise immunity.
Applications
The A5191HRT is designed for use in various industrial and process control applications, including:
- HART field instruments such as pressure transmitters, temperature transmitters, and flow meters.
- HART masters and gateways for data acquisition and control systems.
- Industrial automation and control systems requiring HART communication protocol.
- Process control systems in industries like oil and gas, chemical processing, and power generation.
Q & A
- What is the primary function of the A5191HRT modem?
The A5191HRT is a single-chip modem designed for use in HART field instruments and masters, providing modulation, demodulation, receive filtering, carrier detection, and transmit-signal shaping.
- What communication protocol does the A5191HRT support?
The A5191HRT supports the HART (Highway Addressable Remote Transducer) communication protocol.
- What are the available package options for the A5191HRT?
The A5191HRT is available in 28-pin PLCC, 32-pin QFN, and 32-pin LQFP packages.
- What is the operating temperature range of the A5191HRT?
The operating temperature range is from -40°C to +85°C.
- What is the recommended external clock frequency for the A5191HRT?
The recommended external clock frequency is 460.8 kHz.
- How does the carrier detect function work in the A5191HRT?
The carrier detect function generates a logic low output if the RxAFI voltage is below CDREF, and it stays high as long as RTSB is high and the next comparator pulse is received within a specified time frame.
- What is the purpose of the bias current resistor in the A5191HRT?
The bias current resistor controls the operating parameters of the internal operational amplifiers and comparators.
- Can the A5191HRT be used with an internal oscillator?
Yes, the A5191HRT can be used with an internal oscillator connected to a 460.8 kHz ceramic resonator.
- What is the communication speed of the A5191HRT?
The communication speed is 1200 baud.
- Is the A5191HRT RoHS compliant?
Yes, the A5191HRT is RoHS compliant and available in green packaging options.
