16-Bit, Low-Power, 2-Channel, Sigma-Delta ADC

Please check latest availability status for a specific part variant.


The MX7705 low-power, 2-channel, serial-output analog-to-digital converter (ADC) includes a sigma-delta modulator with a digital filter to achieve 16-bit resolution with no missing codes. This ADC is pin compatible and software compatible with the AD7705. The MX7705 features an on-chip input buffer and programmable-gain amplifier (PGA). The device offers an SPI-/QSPI™-/MICROWIRE ®-compatible serial interface.

The MX7705 operates from a single 2.7V to 5.25V supply. The operating supply current is 320µA (typ) with a 3V supply. Power-down mode reduces the supply current to 2µA (typ).

Self-calibration and system calibration allow the MX7705 to correct for gain and offset errors. Excellent DC performance (±0.003% FSR INL) and low noise (650nV) make the MX7705 ideal for measuring low-frequency signals with a wide dynamic range. The device accepts fully differential bipolar/unipolar inputs. An internal input buffer allows for input signals with high source impedances. An on-chip digital filter, with a programmable cutoff and output data rate, processes the output of the sigma-delta modulator. The first notch frequency of the digital filter is chosen to provide 150dB rejection of common-mode 50Hz or 60Hz noise and 98dB rejection of normal-mode 50Hz or 60Hz noise. A PGA and digital filtering allow signals to be directly acquired with little or no signal-conditioning requirements.

The MX7705 is available in a 16-pin TSSOP package.
MX7705: Functional Diagram MX7705: Functional Diagram Enlarge+

Key Features

  • Pin Compatible and Software Compatible with the AD7705
  • 16-Bit Sigma-Delta ADC
  • Two Fully Differential Input Channels
  • 0.003% Integral Nonlinearity with No Missing Codes
  • Interface with Schmitt Triggers on Inputs
  • Internal Analog Input Buffers
  • PGA from 1 to 128
  • Single (2.7V to 3.6V) or (4.75V to 5.25V) Supply
  • Low Power
    • 1mW (max), 3V Supply
    • 2µA (typ) Power-Down Current
  • SPI-/QSPI-/MICROWIRE-Compatible 3-Wire Serial Interface


  • Flow and Gas Meters
  • Industrial Instruments
  • Loop-Powered Systems
  • Medical Instrumentation
  • Pressure Transducers
  • RTD Measurements
  • Strain-Gauge Measurements
  • Thermocouple Measurements
  • Weigh Scales

See parametric specs for Precision ADCs (< 5Msps) (432)

Part NumberResolution
Input ChannelsConv. Rate
ADC ArchitectureData BusDiff/S.E. InputExternal VREF
External VREF
Unipolar VIN
Bipolar VIN
ADCmaxminmaxmaxmaxSee Notes
MX7705 1620.5Sigma-DeltaSPIDiff. Only13.
SOIC (W)/16
$4.56 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
Request Reliability Report for: MX7705 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >


Related Resources