Industrial Functional Safety

The ADFS5758 is a single-channel, 16-bit, current/voltage output DAC. The device is functional safety approved for unipolar current output and is a fully compliant item with a systematic capability of SC3, which can be used in safety-related applications up to SIL 2, according to IEC 61508. This arrangement allows a single ADFS5758 to be used to achieve SIL 2 for a nonredundant configuration. The safe state for the ADFS5758 is open circuit/high impedance.

The ADFS5758 is a single-channel, voltage and current output digital-to-analog converter (DAC) that operates with a power supply range from −33 V minimum on AV_SS to +33 V maximum on AV_DD1 with a maximum operating voltage between the two rails of 60 V. On-chip dynamic power control (DPC) minimizes package power dissipation, which is achieved by regulating the supply voltage (V_DPC+) to the VI_OUT output driver circuitry from 4.95 V to 27 V using a buck dc-to-dc converter, optimized for minimum on-chip power dissipation. The CHART pin enables a HART^® signal to be coupled onto the current output.

The device uses a versatile 4-wire serial peripheral interface (SPI) that operates at clock rates of up to 50 MHz and is compatible with standard SPI, QSPI™, MICROWIRE™, DSP, and microcontroller interface standards. The interface also features an optional SPI cyclic redundancy check (CRC) and a windowed watchdog timer. The ADFS5758 offers improved diagnostic features from its predecessors, such as an integrated independent 12-bit diagnostic analog-to-digital converter (ADC) that can be used to digitize both internal and external nodes.

Product HighIights

1. Functional safety approved to SIL 2/SC3 by TÜV Rheinland.
2. Range of advanced diagnostic features, including an integrated ADC for high reliability.
3. DPC using an integrated buck dc-to-dc converter for thermal management. When used with the ADP1031, the ADFS5758 enables eight channel to channel isolated outputs at <2 W dissipated power.
4. Programmable power control (PPC) mode to enable faster settling time (15 µs typical).
5. Highly robust with output protection from miswire events (±38 V).

Applications

• Process control
• Actuator control
• Channel isolated analog outputs
• Programmable logic controller (PLC) and distributed control system (DCS) applications
• HART network connectivity

The AD7124-4 is a low power, low noise, completely integrated analog front end for high precision measurement applications. The device contains a low noise, 24-bit Σ-Δ analog-to-digital converter (ADC), and can be configured to have 4 differential inputs or 7 single-ended or pseudo differential inputs. The onchip low gain stage ensures that signals of small amplitude can be interfaced directly to the ADC.

One of the major advantages of the AD7124-4 is that it gives the user the flexibility to employ one of three integrated power modes. The current consumption, range of output data rates, and rms noise can be tailored with the power mode selected. The device also offers a multitude of filter options, ensuring that the user has the highest degree of flexibility.

The AD7124-4 can achieve simultaneous 50 Hz and 60 Hz rejection when operating at an output data rate of 25 SPS (single cycle settling), with rejection in excess of 80 dB achieved at lower output data rates.

The AD7124-4 establishes the highest degree of signal chain integration. The device contains a precision, low noise, low drift internal band gap reference, and also accepts an external differential reference, which can be internally buffered. Other key integrated features include programmable low drift excitation current sources, burnout currents, and a bias voltage generator, which sets the common-mode voltage of a channel to AV_DD/2. The low-side power switch enables the user to power down bridge sensors between conversions, ensuring the absolute minimal power consumption of the system. The device also allows the user the option of operating with either an internal clock or an external clock.

The integrated channel sequencer allows several channels to be enabled simultaneously, and the AD7124-4 sequentially converts on each enabled channel, simplifying communication with the device. As many as 16 channels can be enabled at any time; a channel being defined as an analog input or a diagnostic such as a power supply check or a reference check. This unique feature allows diagnostics to be interleaved with conversions.

The AD7124-4 also supports per channel configuration. The device allows eight configurations or setups. Each configuration consists of gain, filter type, output data rate, buffering, and reference source. The user can assign any of these setups on a channel by channel basis.

The AD7124-4 also has extensive diagnostic functionality integrated as part of its comprehensive feature set. These diagnostics include a cyclic redundancy check (CRC), signal chain checks, and serial interface checks, which lead to a more robust solution. These diagnostics reduce the need for external components to implement diagnostics, resulting in reduced board space needs, reduced design cycle times, and cost savings. The failure modes effects and diagnostic analysis (FMEDA) of a typical application has shown a safe failure fraction (SFF) greater than 90% according to IEC 61508.

The device operates with a single analog power supply from 2.7 V to 3.6 V or a dual 1.8 V power supply. The digital supply has a range of 1.65 V to 3.6 V. It is specified for a temperature range of −40°C to +105°C. The AD7124-4 is housed in a 32-lead LFCSP package or a 24-lead TSSOP package.

Applications

• Temperature measurement 
• Pressure measurement 
• Industrial process control 
• Instrumentation Smart transmitters
• Smart transmitters

The AD7124-8 is a low power, low noise, completely integrated analog front end for high precision measurement applications. The device contains a low noise, 24-bit Σ-Δ analog-to-digital converter (ADC), and can be configured to have 8 differential inputs or 15 single-ended or pseudo differential inputs. The onchip low gain stage ensures that signals of small amplitude can be interfaced directly to the ADC.

One of the major advantages of the AD7124-8 is that it gives the user the flexibility to employ one of three integrated power modes. The current consumption, range of output data rates, and rms noise can be tailored with the power mode selected. The device also offers a multitude of filter options, ensuring that the user has the highest degree of flexibility. The AD7124-8 can achieve simultaneous 50 Hz and 60 Hz rejection when operating at an output data rate of 25 SPS (single cycle settling), with rejection in excess of 80 dB achieved at lower output data rates.

The AD7124-8 establishes the highest degree of signal chain integration. The device contains a precision, low noise, low drift internal band gap reference and accepts an external differential reference, which can be internally buffered. Other key integrated features include programmable low drift excitation current sources, burnout currents, and a bias voltage generator, which sets the common-mode voltage of a channel to AV_DD/2. The low-side power switch enables the user to power down bridge sensors between conversions, ensuring the absolute minimal power consumption of the system. The device also allows the user the option of operating with either an internal clock or an external clock.

The integrated channel sequencer allows several channels to be enabled simultaneously, and the AD7124-8 sequentially converts on each enabled channel, simplifying communication with the device. As many as 16 channels can be enabled at any time, a channel being defined as an analog input or a diagnostic such as a power supply check or a reference check. This unique feature allows diagnostics to be interleaved with conversions. The AD7124-8 also supports per channel configuration. The device allows eight configurations or setups. Each configuration consists of gain, filter type, output data rate, buffering, and reference source. The user can assign any of these setups on a channel by channel basis.

The AD7124-8 also has extensive diagnostic functionality integrated as part of its comprehensive feature set. These diagnostics include a cyclic redundancy check (CRC), signal chain checks, and serial interface checks, which lead to a more robust solution. These diagnostics reduce the need for external components to implement diagnostics, resulting in reduced board space needs, reduced design cycle times, and cost savings. The failure modes effects and diagnostic analysis (FMEDA) of a typical application has shown a safe failure fraction (SFF) greater than 90% according to IEC 61508.

The device operates with a single analog power supply from 2.7 V to 3.6 V or a dual 1.8 V power supply. The digital supply has a range of 1.65 V to 3.6 V. It is specified for a temperature range of −40°C to +125°C. The AD7124-8 is housed in a 32-lead LFCSP package.

Note that, throughout this data sheet, multifunction pins, such as DOUT/RDY, are referred to either by the entire pin name or by a single function of the pin, for example, RDY, when only that function is relevant.

Applications

• Temperature measurement
• Pressure measurement
• Industrial process control
• Instrumentation
• Smart transmitters

The AD7902 is a dual 16-bit, successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDDx, per ADC. It contains two low power, high speed, 16-bit sampling ADCs and a versatile serial port interface (SPI). On the CNVx rising edge, the AD7902 samples an analog input,  IN+ in the range of 0 V to VREF with respect to a ground sense, IN−. The externally applied reference voltage of the REFx pins (V_REF) can be set independently from the supply voltage pins, VDDx. The power of the device scales linearly with throughput.

Using the SDIx inputs, the SPI-compatible serial interface can also daisy-chain multiple ADCs on a single 3-wire bus and provide an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic, using the separate VIOx supplies.

The AD7902 is available in a 20-lead QSOP package with operation specified from −40°C to +125°C.

APPLICATIONS

• Battery-powered equipment
• Communications
• Automated test equipment (ATE)
• Data acquisition
• Medical instrumentation
• Redundant measurement
• Simultaneous sampling

The AD7770 is an 8-channel, simultaneous sampling ADC. Eight full sigma-delta (Σ-Δ) ADCs are on chip. The AD7770 provides a low input current to allow direct sensor connection. Each input channel has a programmable gain stage allowing gains of 1, 2, 4, and 8 to map lower amplitude sensor outputs into the full-scale ADC input range, maximizing the dynamic range of the signal chain. The AD7770 accepts a VREF voltage from 1 V up to 3.6 V.

The analog inputs accept unipolar (0 V to V_REF) or true bipolar (±V_REF/2) analog input signals with 3.3 V or ±1.65 V analog supply voltages, respectively for PGA_GAIN = 1. The analog inputs can be configured to accept true differential, pseudo differential, or single-ended signals to match different sensor output configurations.

Each channel contains a PGA, an ADC modulator and a sinc3, low latency digital filter. An SRC is provided to allow fine resolution control over the AD7770 ODR. This control can be used in applications where the ODR resolution is required to maintain coherency with 0.01 Hz changes in the line frequency. The SRC is programmable through the serial port interface (SPI). The AD7770 implements two different interfaces: a data output interface and SPI control interface. The ADC data output interface is dedicated to transmitting the ADC conversion results from the AD7770 to the processor. The SPI writes to and reads from the AD7770 configuration registers and for the control and reading of data from the SAR ADC. The SPI can also be configured to output the Σ-Δ conversion data.

The AD7770 includes a 12-bit SAR ADC. This ADC can be used for AD7770 diagnostics without having to decommission one of the Σ-Δ ADC channels dedicated to system measurement functions. With the use of an external multiplexer, which can be controlled through the three general-purpose input/output pins (GPIOs), and signal conditioning, the SAR ADC can validate the Σ-Δ ADC measurements in applications where functional safety is required. In addition, the AD7770 SAR ADC includes an internal multiplexer to sense internal nodes.

The AD7770 contains a 2.5 V reference and reference buffer. The reference has a typical temperature coefficient of 10 ppm/°C.

The AD7770 offers two modes of operation: high resolution mode and low power mode. High resolution mode provides a higher dynamic range while consuming 10.75 mW per channel; low power mode consumes just 3.37 mW per channel at a reduced dynamic range specification.

The specified operating temperature range is −40°C to +105°C, although the device is operational up to +125°C.

Applications

• Protection relays
• General-purpose data acquisition
• Industrial process control

The ADCMP671 voltage monitor consists of two low power, high accuracy comparators and reference circuits. It operates on a supply voltage from 1.7 V to 5.5 V and draws only 8.55 μA maximum, making it suitable for low power system monitoring and portable applications. The part is designed to monitor and report supply undervoltage and overvoltage fault. The low input bias current and voltage reference allows resistor adjustable UV and OV threshold down to 400 mV. The ADCMP671 has two open-drain outputs: the PWRGD output indicates that the supply is within the UV and OV window, and the OV output indicates that the supply is overvoltage. This output combination allows users to window monitor N supplies with an N + 1 processor input/output (I/O). Each output is guaranteed to sink greater than 5 mA over temperature.

The ADCMP671 is available in 6-lead TSOT package. The device operates over the -40°C to +125°C temperature range.

APPLICATIONS

• Supply voltage monitoring
• Li-ion monitoring
• Portable applications
• Handheld instruments