AD7705
PRODUCTION3V/5V, 1 mW, 2-Channel Differential, 16-Bit Sigma-Delta ADC
- Part Models
- 7
- 1ku List Price
- Starting From $6.50
Part Details
- Two Fully Differential Input Channel ADCs
- Programmable Gain Front End Gains from 1 to 128
- Three-Wire Serial Interface
SPI®, QSPI™, MICROWIRE™ and DSP Compatible Schmitt Trigger Input on SCLK
- Ability to Buffer the Analog Input
- 2.7 V to 3.3 V or 4.75 V to 5.25 V Operation
- Power Dissipation 1 mW max @ 3 V
- Standby Current 8 µA max
- 16-Lead DIP, 16-Lead SOIC and TSSOP Packages
The AD7705 / AD7706 are complete analog front ends for low frequency measurement applications. These 2-/3-channel devices can accept low level input signals directly from a transducer and produce serial digital output. The devices employ a Σ-Δ conversion technique to realize up to 16 bits of no missing codes performance. The selected 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 an on-chip control register, allowing adjustment of the filter cutoff and output update rate.
The AD7705 / AD7706 devices operate from a single 2.7 V to 3.3 V or 4.75 V to 5.25 V supply. The AD7705 features two fully differential analog input channels; the AD7706 features three pseudo differential input channels.
Both devices feature a differential reference input. Input signal ranges of 0 mV to 20 mV through 0 V to 2.5 V can be incorporated on both devices when operating with a VDD of 5 V and a reference of 2.5 V. They can also handle bipolar input signal ranges of ±20 mV through ±2.5 V, which are referenced to the AIN(−) inputs on the AD7705 and to the COMMON input on the AD7706.
The AD7705 / AD7706 devices, with a 3 V supply and a 1.225 V reference, can handle unipolar input signal ranges of 0 mV to 10 mV through 0 V to 1.225 V. The devices can accept bipolar input ranges of ±10 mV through ±1.225 V. Therefore, the AD7705 / AD7706 devices perform all signal conditioning and conversion for a 2-channel or 3-channel system.
The AD7705 / AD7706 are ideal for use in smart, microcontroller, or DSP-based systems. The devices feature a serial interface that can be configured for 3-wire operation. Gain settings, signal polarity, and update rate selection can be configured in software using the input serial port. The parts 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 the power-down mode reduces the standby power consumption to 20 μW typ.
These parts are available in a 16-lead, wide body (0.3 inch), plastic dual in-line package (DIP); a 16-lead, wide body (0.3 inch), standard small outline (SOIC) package; and a low profile, 16-lead, thin shrink small outline package (TSSOP).
Documentation
Data Sheet 1
Application Note 13
Technical Articles 4
Frequently Asked Question 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| AD7705BNZ | 16-Lead PDIP | ||
| AD7705BRUZ | 16-Lead TSSOP | ||
| AD7705BRUZ-REEL | 16-Lead TSSOP | ||
| AD7705BRUZ-REEL7 | 16-Lead TSSOP | ||
| AD7705BRZ | 16-Lead SOIC Wide | ||
| AD7705BRZ-REEL | 16-Lead SOIC Wide | ||
| AD7705BRZ-REEL7 | 16-Lead SOIC Wide |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Jul 21, 2023 - 23_0082 Qualification of Alternate Wafer Fab Site at ADI Limerick for Select ADC Products |
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| AD7705BNZ | PRODUCTION | |
| AD7705BRUZ | PRODUCTION | |
| AD7705BRUZ-REEL | PRODUCTION | |
| AD7705BRUZ-REEL7 | PRODUCTION | |
| AD7705BRZ | PRODUCTION | |
| AD7705BRZ-REEL | PRODUCTION | |
| AD7705BRZ-REEL7 | PRODUCTION | |
|
Mar 29, 2021 - 21_0033 Assembly Site Transfer for 14/16L 300_MIL PDIP to Cirtek |
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| AD7705BNZ | PRODUCTION | |
|
Aug 19, 2009 - 07_0024 Package Material Changes for SOT23, MiniSO, MQFP, PDIP, PLCC, SOIC (narrow and wide body), SSOP, TSSOP and TSSOP exposed pad |
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| AD7705BNZ | PRODUCTION | |
|
Apr 5, 2021 - 21_0035 Amkor Philippines as an Alternate Site for TSSOP_4.4 |
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| AD7705BRUZ | PRODUCTION | |
| AD7705BRUZ-REEL | PRODUCTION | |
| AD7705BRUZ-REEL7 | PRODUCTION | |
|
Jan 20, 2012 - 11_0218 Halogen Free Material Change for Certain TSSOP Products at Carsem |
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| AD7705BRUZ | PRODUCTION | |
| AD7705BRUZ-REEL | PRODUCTION | |
| AD7705BRUZ-REEL7 | PRODUCTION | |
|
Aug 4, 2010 - 10_0117 Halogen Free Material Change for SOIC_W Products at Carsem |
||
| AD7705BRZ | PRODUCTION | |
| AD7705BRZ-REEL | PRODUCTION | |
| AD7705BRZ-REEL7 | PRODUCTION | |
|
Feb 8, 2010 - 04_0080 Qualification of the 8" C6 and Q Wafer Fab Processes at Analog Devices, Limerick, Ireland. |
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| AD7705BRZ | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Request a Driver/SoftwareHardware Ecosystem
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| isoPower 3 | ||
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| Series Voltage References 2 | ||
| REF43 | NOT RECOMMENDED FOR NEW DESIGNS | +2.5V Low Power Precision Voltage Reference |
| REF192 | PRODUCTION | 2.5V Precision Micropower, Low Dropout, Low Voltage Reference |
| Shunt Voltage References 4 | ||
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| AD589 | NOT RECOMMENDED FOR NEW DESIGNS | Two-Terminal IC 1.2 V Reference |
| AD1580 | PRODUCTION | 1.2 V Micropower, Precision Shunt Voltage Reference |
| ADR512 | PRODUCTION | 1.2 V Precision Low Noise Shunt Voltage Reference |
| Standard Digital Isolators 5 | ||
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| ADUM7441 | PRODUCTION | 1 kV RMS Quad-Channel Digital Isolator |
| ADUM7442 | PRODUCTION | 1 kV RMS Quad-Channel Digital Isolator |
| ADUM1400 | PRODUCTION | Quad-Channel Digital Isolator (4/0 Channel Directionality) |
| ADUM1200 | PRODUCTION | Dual-Channel Digital Isolator (2/0 Channel Directionality) |
| USB Isolators 1 | ||
| ADUM4160 | PRODUCTION | Full/Low Speed USB Digital Isolator |
Tools & Simulations
Sigma-Delta ADC Tutorial
An interactive illustration showing the behavior of an idealized sigma-delta A/D converter.
Open ToolEvaluation Kits
AD7705 Evaluation Kit