Low-Power, Serial, 12-Bit DACs with Force-Sense Voltage-Output

The MAX5175/MAX5177 low-power, serial, voltage-output, 12-bit digital-to-analog converters (DACs) feature a precision output amplifier in a space-saving 16-pin QSOP package. The MAX5175 operates from a single +5V supply, and the MAX5177 operates from a single +3V supply. The output amplifier's inverting input is available to allow specific gain configurations, remote sensing, and high output current capability. This makes the MAX5175/MAX5177 ideal for a wide range of applications, including industrial process control. Both devices draw only 260µA of supply current, which reduces to 1µA in shutdown mode. In addition, the programmable power-up reset feature allows for a user-selectable output voltage state of either 0 or midscale.

The 3-wire serial interface is compatible with SPI™, QSPI™, and MICROWIRE™ standards. An input register followed by a DAC register provides a double-buffered input, allowing the registers to be updated independently or simultaneously with a 16-bit serial word. Additional features include software and hardware shutdown, shutdown lockout, a hardware reset pin, and a reference input capable of accepting DC and offset AC signals. These devices provide a programmable digital output pin for added functionality and a serial-data output pin for daisy-chaining. All logic inputs are TTL/CMOS compatible and are internally buffered with Schmitt triggers to allow direct interfacing to optocouplers.

The MAX5175/MAX5177 incorporate a proprietary on-chip circuit that keeps the output voltage virtually "glitch free," limiting the glitches to a few millivolts during power-up.

Both devices come in 16-pin QSOP packages and are specified for the extended (-40°C to +85°C) temperature range. The MAX5171/MAX5173 are 14-bit pin-compatible upgrades to the MAX5175/MAX5177. For pin-compatible DACs with an internal reference, see the 13-bit MAX5132/MAX5133 and 12-bit MAX5122/MAX5123.

Applications

* Digital Gain and Offset Control * Digitally Programmable 4mA–20mA Current Loops * General Purpose * Industrial Process Controls * Motion Control * Remote Industrial Controls

* ±1 LSB INL

* 1µA Shutdown Current

* "Glitch Free" Output Voltage at Power-Up

* Single-Supply Operation

* +5V (MAX5175)

* +3V (MAX5177)

* Full-Scale Output Range

* +2.048V (MAX5177, VREF = +1.25V)

* +4.096V (MAX5175, VREF = +2.5V)

* Rail-to-Rail Output Amplifier

* Adjustable Output Offset

* Low THD (-80dB) in Multiplying Operation

* SPI/QSPI/MICROWIRE-Compatible 3-Wire Serial Interface

* Programmable Shutdown Mode and Power-Up Reset (0 or midscale)

* Buffered Output Capable of Driving 4-20mA or 5kΩ || 100pF Loads

* User-Programmable Digital Output Pin Allows Serial Control of External Components

* 14-Bit Upgrades Available (MAX5171/MAX5173)