AD7715AR-5

3 V / 5 V ， 450 uA的16位， Σ-Δ ADC 3 V/5 V, 450 uA 16-Bit, Sigma-Delta ADC

Product Details

The AD7715 is a complete analog front end for low frequency measurement applications. The part can accept low level input signals directly from a transducer and outputs a serial digital word. It employs a Σ-Δ conversion technique to realize up to 16 bits of no missing codes performance. The input signal is applied to a proprietary programmable gain front end based around an analog modulator. The modulator output is processed by an on-chip digital filter. The first notch of this digital filter can be programmed via the on-chip control register allowing adjustment of the filter cutoff and output update rate.

The AD7715 features a differential analog input as well as a differential reference input. It operates from a single supply 3 V or 5 V. It can handle unipolar input signal ranges of 0 mV to 20 mV, 0 mV to 80 mV, 0 V to 1.25 V and 0 V to 2.5 V. It can also handle bipolar input signal ranges of ±20 mV, ±80 mV, ±1.25 V and ±2.5 V. These bipolar ranges are referenced to the negative input of the differential analog input. The AD7715 thus performs all signal conditioning and conversion for a single channel system.

The AD7715 is ideal for use in smart, microcontroller, or DSP-based systems. It features a serial interface that can be configured for three-wire operation. Gain settings, signal polarity, and update rate selection can be configured in software using the input serial port. The part contains self-calibration and system calibration options to eliminate gain and offset errors on the part itself or in the system.

CMOS construction ensures very low power dissipation, and power-down mode reduces the standby power consumption to 50 μW typical. The part is available in a 16-lead, 0.3 inch-wide, plastic dual-in-line package PDIP as well as a 16-lead 0.3 inch wide small outline SOIC_W package and a 16-lead TSSOP package.

**Product Highlights**

1. The AD7715 consumes less than 450 μA in total supply current at 3 V supplies and 1 MHz master clock, making it ideal for use in low-power systems. Standby current is less than 10 μA.

2. The programmable gain input allows the AD7715 to accept input signals directly from a strain gage or transducer removing a considerable amount of signal conditioning.

3. The AD7715 is ideal for microcontroller or DSP processor applications with a three-wire serial interface reducing the number of interconnect lines and reducing the number of optocouplers required in isolated systems. The part contains on-chip registers which allow software control over output update rate, input gain, signal polarity, and calibration modes.

4. The part features excellent static performance specifications with 16-bits no missing codes, ±0.0015% accuracy, and low rms noise <550 nV. Endpoint errors and the effects of temperature drift are eliminated by on-chip calibration options, which remove zero-scale and full-scale errors.

### Features and Benefits

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Charge-balancing ADC

16-bits no missing codes

0.0015% nonlinearity

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Programmable gain front end

Gains of 1, 2, 32 and 128

Differential input capability

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Three-wire serial interface

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SPI-, QSPI™-, MICROWIRE™-, and DSP-compatible

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Ability to buffer the analog input

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3 V AD7715-3 or 5 V AD7715-5 operation

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Low supply current: 450 μA maximum @ 3 V supplies

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Low-pass filter with programmable output update

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16-lead SOIC/PDIP/TSSOP