The AD7785 is a low power, low noise, complete analog front ends for high precision measurement applications. It contains a low noise 20-bit Σ-Δ ADC with three differential analog inputs. The on-chip, low noise instrumentation amplifier means that signals of small amplitude can be interfaced directly to the ADC. With a gain setting of 64, the rms noise is 40 nV when the update rate equals 4.17 Hz.

The device contains a precision low noise, low drift internal band gap reference and can also accept an external differential reference. Other on-chip features include programmable excitation current sources, burnout currents, and a bias voltage generator, the bias voltage generator being used to set the common-mode voltage of a channel to AV_DD/2.

The device can be operated with either the internal clock or an external clock. The output data rate from the part is software-programmable and can be varied from 4.17 Hz to 470 Hz.

The part operates with a power supply from 2.7 V to 5.25 V. It consumes a current of 400 µA typical and is housed in 16-lead TSSOP packages.

Applications

Thermocouple measurements

RTD measurements

Thermistor measurements

Gas analysis

Industrial process control

Instrumentation

Portable instrumentation

Blood analysis

Smart transmitters

Liquid/gas chromatography

6-digit DVM

Part#	Res	Throughput Rate	# of Inputs	Operating Pwr Diss
AD7785	20	470SPS	3	2.5mW
AD7792	16	470SPS	3	2.5mW
AD7793	24	470SPS	3	2.5mW
AD7798	16	470SPS	3	2mW
AD7799	24	470SPS	3	2.5mW
AD7703	20	4KSPS	1	37mW
AD7450	12	1MSPS	1	1.3mW
AD7466	12	200KSPS	1	900µW
AD7467	10	200KSPS	1	630µW
AD7468	8	200KSPS	1	570µW
AD7794	24	470SPS	6	2.5mW

The model number is a specific version of a generic that can be purchased or sampled.

Status indicates the current lifecycle of the product. This can be one of 4 stages:

• Pre-Release: The model has not been released to general production, but samples may be available.
• Production: The model is currently being produced, and generally available for purchase and sampling.
• Last Time Buy: The model has been scheduled for obsolescence, but may still be purchased for a limited time.
• Obsolete: The specific part is obsolete and no longer available. Other models listed in the table may still be available (if they have a status that is not obsolete).

The package for this IC (i.e. DIP, SOIC, BGA). An Evaluation Board is a board engineered to show the performance of the model, the part is included on the board.

For detailed drawings and chemical composition please consult our  Package Site

Pin Count is the number of pins, balls, or pads on the device. Pin-out diagrams & pin function descriptions may be found in the datasheet.

This is the acceptable operating range of the device. The various ranges specified are as follows:

• Commercial: 0 to +70 degrees Celsius
• Military : -55 to +125 degrees Celsius
• Industrial: Temperature ranges may vary by model. Please consult the datasheet for more information.
• Automotive: -40 to +125 degrees Celsius

The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

This is the date Analog Devices, Inc. anticipates that the product will ship from the warehouse. Most orders ship within 48 hours of this date.Once an order has been placed, Analog Devices, Inc. will send an Order Acknowledgement email to confirm your delivery date. It is important to note the scheduled dock date on the order entry screen. We do take orders for items that are not in stock, so delivery may be scheduled at a future date. Also, please note the warehouse location for the product ordered. We have warehouses in the United States, Europe and Southeast Asia. Transit times from these sites may vary.

Due to environmental concerns, ADI offers many of our products in lead-free versions. For more information about lead-free parts, please consult our Pb (Lead) free information page.