Field instruments or smart transmitters monitor process control variables, such as temperature, pressure, level and flow. Analog Devices offer a wide range of products, signal chain solutions, and technical expertise to help engineers meet today’s design challenges.
The ADuCM360/ADuCM361 contain an on-chip 32 kHz oscillator and an internal 16 MHz high frequency oscillator. The high frequency oscillator is routed through a programmable clock divider from which the operating frequency of the processor core clock is generated. The maximum core clock speed is 16 MHz; this speed is not limited by operating voltage or temperature.
The microcontroller core is a low power ARM Cortex-M3 processor, a 32-bit RISC machine that offers up to 20 MIPS peak performance. The Cortex-M3 processor incorporates a flexible, 11-channel DMA controller that supports all wired communica-tion peripherals (SPI, UART, and I2C). Also integrated on chip are 128 kB of nonvolatile Flash/EE memory and 8 kB of SRAM.
The analog subsystem consists of dual ADCs, each connected to a flexible input mux. Both ADCs can operate in fully differential and single-ended modes. Other on-chip ADC features include dual programmable excitation current sources, diagnostic current sources, and a bias voltage generator of AVDD_REG/2 (900 mV) to set the common-mode voltage of an input channel. A low-side internal ground switch is provided to allow power-down of an external circuit (for example, a bridge circuit) between conversions.
The ADCs contain two parallel filters: a sinc3 or sinc4 filter in parallel with a sinc2 filter. The sinc3 or sinc4 filter is used for precision measurements. The sinc2 filter is used for fast measure-ments and for the detection of step changes in the input signal.
The devices contain a low noise, low drift internal band gap ref-erence, but they can be configured to accept one or two external reference sources in ratiometric measurement configurations. An option to buffer the external reference inputs is provided on chip. A single-channel buffered voltage output DAC is also provided on chip.
The ADuCM360/ADuCM361 integrate a range of on-chip peripherals, which can be configured under microcontroller software control as required in the application. The peripherals include UART, I2C, and dual SPI serial I/O communication controllers; a 19-pin GPIO port; two general-purpose timers; a wake-up timer; and a system watchdog timer. A 16-bit PWM controller with six output channels is also provided.
The ADuCM360/ADuCM361 are specifically designed to operate in battery-powered applications where low power operation is critical. The microcontroller core can be configured in a normal operating mode that consumes 290 μA/MHz (including flash/ SRAM IDD). An overall system current consumption of 1 mA can be achieved with both ADCs on (input buffers off), PGA gain of 4, one SPI port on, and all timers on.
The ADuCM360/ADuCM361 can be configured in a number of low power operating modes under direct program control, including a hibernate mode (internal wake-up timer active) that consumes only 4 μA. In hibernate mode, peripherals such as external interrupts or the internal wake-up timer can wake up the device. This mode allows the part to operate with ultralow power and still respond to asynchronous external or periodic events.
- Industrial automation and process control
- Intelligent precision sensing systems
- 4 mA to 20 mA loop-powered smart sensor systems
- Medical devices, patient monitoring
- Body-Worn Insulin Pump
Instrumentation and Measurement
- Environmental Monitoring
The AD5700/AD5700-1 are single-chip solutions, designed and specified to operate as a HART® FSK half-duplex modem, complying with the HART physical layer requirements. The AD5700/AD5700-1 integrate all of the necessary filtering, signal detection, modulating, demodulating and signal generation functions, thus requiring few external components. The 0.5% precision internal oscillator on the AD5700-1 greatly reduces the board space requirements, making it ideal for line-powered applications in both master and slave configurations. The maximum supply current consumption is 115µA, making theAD5700/AD5700-1 an optimal choice for low power loop-powered applications. Transmit waveforms are phase continuous 1200 Hz and 2200 Hz sinusoids. The AD5700/AD5700-1 contain accurate carrier detect circuitry and use a standard UART interface.
- Field transmitters
- HART multiplexers
- PLC and DCS analog I/O modules
- HART network connectivity
The ADuM1440 is a micropower, quad-channel digital isolator which has a default high and 4/0 channel directionality based on the Analog Devices, Inc., iCoupler® technology. (Dual-channel products available.) Combining high speed, complementary metal oxide semiconductor (CMOS) and monolithic air core transformer technologies, these isolation components provide outstanding performance characteristics superior to the alternatives, such as optocoupler devices, while requiring the lowest power of any available isolation product. The ENX signals can be used to disable the internal refresh, which lowers the total quiescent current to less than 1 µA.
The ADuM1440/ADuM1441/ADuM1442/ADuM1445/ADuM1446/ADuM1447 family of quad 2.5 kV digital isolation devices are packaged in a small 16-lead QSOP and 20-lead SSOP. While most 4-channel isolators come in 16-lead wide SOIC packages, the ADuM1440/ADuM1441/ADuM1442/ ADuM1445/ADuM1446/ADuM1447 frees almost 70% of board space and yet can still withstand high isolation voltages and meet regulatory requirements, such as UL and CSA standards (pending). In addition to the space savings, the ADuM1440/ADuM1441/ADuM1442/ ADuM1445/ADuM1446/ADuM1447 operates with supplies as low as 2.25 V.
Despite the low power consumption, all models of the ADuM1440/ ADuM1441/ ADuM1442/ ADuM1445/ ADuM1446/ ADuM1447 provide low, pulse width distortion <8 ns. In addition, every model has an input glitch filter to protect against extraneous noise disturbances.
- General-purpose, low power multichannel isolation
- 1 MHz, low power peripheral interface (SPI)
- 4 mA to 20 mA loop process controls
- Hybrid Electric Vehicles