Single-Channel, 16-Bit Current and Voltage Output DAC with Dynamic Power Control and HART Connectivity

The AD5758 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 AVSS to +33 V (maximum) on AVDD1 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 (VDPC+) to the VIOUT output driver circuitry from 5 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 watchdog timer (WDT). The AD5758 offers improved diagnostic features from its predecessors, such as an integrated 12-bit diagnostic analog-to-digital converter (ADC). Additional robustness is provided by the inclusion of a line protector on the VIOUT, +VSENSE, and −VSENSE pins. When used with its companion power management unit (PMU)/isolator (ADP1031), the AD5758 is capable of enabling customers to develop an eight channel to channel isolated analog output module with less than 2 W power dissipation, while meeting CISPR 11 Class B.

Product Highlights

* DPC, using an integrated buck dc-to-dc converter for thermal management. When used with the ADP1031, the AD5758 enables eight channel to channel isolated outputs at <2 W dissipated power.

* Range of advanced diagnostic features, including an integrated ADC for high reliability.

* Highly robust with output protection from miswire events (±38 V).

* HART compliant.

Applications

* Process control

* Actuator control

* Channel isolated analog outputs

* Programmable logic controller (PLC) and distributed control systems (DCS) applications

* HART network connectivity

* 16-bit resolution and monotonicity

* DPC for thermal management

* Current/voltage output available on a single terminal

* Current output ranges: 0 mA to 20 mA, 4 mA to 20 mA, 0 mA to 24 mA, ±20 mA, ±24 mA, −1 mA to +22 mA

* Voltage output ranges (with 20% overrange): 0 V to 5 V, 0 V to 10 V, ±5 V, and ±10 V

* User-programmable offset and gain

* Advanced on-chip diagnostics, including a 12-bit ADC

* On-chip reference