AFE781H1 Series

14-bit low-power analog front end (AFE) with DAC, ADC and HART® modem for sensor transmitters

Catalog

14-bit low-power analog front end (AFE) with DAC, ADC and HART® modem for sensor transmitters

Part	Voltage - Supply, Digital [Min]	Voltage - Supply, Digital [Max]	Package / Case	Supplier Device Package [y]	Supplier Device Package	Supplier Device Package [x]	Mounting Type	Voltage - Supply, Analog [Max]	Voltage - Supply, Analog [Min]	Number of Channels [custom]	Number of Bits
Texas Instruments AFE781H1RRUT	1.71 V	5.5 V	24-WFQFN	4	24-UQFN	4	Surface Mount	1.89 V	1.71 V	2	12 14 16

Catalog

14-bit low-power analog front end (AFE) with DAC, ADC and HART® modem for sensor transmitters

Key Features

• Functional Safety-CapableDocumentation available to aid functional safety system design:AFE881H1,AFE781H1Low quiescent current: 180 µA (typical)HART-compliant physical layer modem16-bit or 14-bit monotonic high-performance DAC1.8-V supply: 0.15 V to 1.25 V, 0.2 V to 1.0 V5-V supply: 0.3 V to 2.5 V, 0.4 V to 2.0 V4-LSB INL at 16 bits0.07% FSR (max) TUE from –40°C to +125°C12-bit 3.84-kSPS ADC for advanced diagnosticsIntegrated 1.25-V reference at 10 ppm/°C (max)Internal 1.2288-MHz oscillator with clock outputDigital interfaceSerial peripheral interface (SPI): Shared bus for both DAC and HARTUniversal asynchronous receiver-transmitter (UART): Shared bus for both DAC and HARTBoth: SPI for DAC and UART for HARTFault detection: CRC bit error checking, windowed watchdog timer, diagnostic ADCDigital DAC slew-rate controlWide operating temperature: –55°C to +125°CFunctional Safety-CapableDocumentation available to aid functional safety system design:AFE881H1,AFE781H1Low quiescent current: 180 µA (typical)HART-compliant physical layer modem16-bit or 14-bit monotonic high-performance DAC1.8-V supply: 0.15 V to 1.25 V, 0.2 V to 1.0 V5-V supply: 0.3 V to 2.5 V, 0.4 V to 2.0 V4-LSB INL at 16 bits0.07% FSR (max) TUE from –40°C to +125°C12-bit 3.84-kSPS ADC for advanced diagnosticsIntegrated 1.25-V reference at 10 ppm/°C (max)Internal 1.2288-MHz oscillator with clock outputDigital interfaceSerial peripheral interface (SPI): Shared bus for both DAC and HARTUniversal asynchronous receiver-transmitter (UART): Shared bus for both DAC and HARTBoth: SPI for DAC and UART for HARTFault detection: CRC bit error checking, windowed watchdog timer, diagnostic ADCDigital DAC slew-rate controlWide operating temperature: –55°C to +125°C

Description

The 16-bit AFE881H1 and 14-bit AFE781H1 ( AFEx81H1) are highly-integrated, high-accuracy, extremely low-power digital-to-analog converters (DACs) with voltage outputs designed for HART-enabled sensor-transmitter applications. The AFEx81H1 devices include most of the components required to design a 4‑mA to 20‑mA, 2‑wire (loop-powered) sensor transmitter. In addition to the highly accurate DAC, these parts include a HART-certified FSK modem, 10‑ppm/°C voltage reference, and diagnostic analog-to-digital converter (ADC). To accommodate intrinsic and functional safety concerns, external voltage-to-current conversion and power regulation are required. The internal diagnostic ADC is multiplexed to several internal nodes that enable an automatic self-health check. If any fault is detected from the diagnostic ADC, CRC frame-error checking, or windowed watchdog timer, the devices can optionally issue an interrupt, enter a fail-safe state corresponding to a standard NAMUR output value or user-specified custom value, or both. These devices operate from supplies as low as 1.71 V with 220 µA maximum quiescent current. The devices are specified over the temperature range of –40°C to +125°C, but are functional from –55°C to +125°C. The 16-bit AFE881H1 and 14-bit AFE781H1 ( AFEx81H1) are highly-integrated, high-accuracy, extremely low-power digital-to-analog converters (DACs) with voltage outputs designed for HART-enabled sensor-transmitter applications. The AFEx81H1 devices include most of the components required to design a 4‑mA to 20‑mA, 2‑wire (loop-powered) sensor transmitter. In addition to the highly accurate DAC, these parts include a HART-certified FSK modem, 10‑ppm/°C voltage reference, and diagnostic analog-to-digital converter (ADC). To accommodate intrinsic and functional safety concerns, external voltage-to-current conversion and power regulation are required. The internal diagnostic ADC is multiplexed to several internal nodes that enable an automatic self-health check. If any fault is detected from the diagnostic ADC, CRC frame-error checking, or windowed watchdog timer, the devices can optionally issue an interrupt, enter a fail-safe state corresponding to a standard NAMUR output value or user-specified custom value, or both. These devices operate from supplies as low as 1.71 V with 220 µA maximum quiescent current. The devices are specified over the temperature range of –40°C to +125°C, but are functional from –55°C to +125°C.