AD7798BRUZ - 16-Bit Sigma-Delta ADC, 3-Channel | Analog Devices
MPN: AD7798BRUZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.62 | $5.62 |
| 10 | $5.1 | $51.00 |
| 100 | $4.52 | $452.00 |
| 500 | $4.1 | $2,050.00 |
| 1,000 | $3.85 | $3,850.00 |
AD7798BRUZ Overview
A Sigma-Delta ADC is a type of analog-to-digital converter that uses oversampling and noise shaping to achieve high resolution and excellent noise performance. It is ideal for low-frequency, high-precision applications such as sensor measurement, industrial process control, and instrumentation. The AD7798BRUZ belongs to the family of Sigma-Delta ADCs, which are part of the broader category of data converters, essential in bridging analog signals to digital processing systems.
Key features of the AD7798BRUZ include a programmable output data rate from 4.17 Hz to 470 Hz, RMS noise as low as 1.5 µV (at 4.17 Hz), and a typical supply current of 400 µA, with a power-down mode consuming only 1 µA. The on-chip in-amp provides gain up to 128, allowing direct connection to low-level sensors such as thermocouples and strain gauges. The SPI-compatible serial interface simplifies communication with microcontrollers and DSPs.
The device architecture includes a chopper-stabilized amplifier, a Sigma-Delta modulator, and a digital filter, ensuring high accuracy and low offset drift. The internal reference and clock reduce external component count, while the low-side power switch enables bridge sensor excitation. The AD7798BRUZ is specified for the industrial temperature range of -40°C to +105°C, making it suitable for harsh environments.
Typical applications include temperature measurement with RTDs and thermocouples, pressure and strain gauge sensing, and battery monitoring. Its low power consumption and high resolution make it ideal for portable and battery-powered instruments. The device is also used in weigh scales and process control systems where precision is critical.
When designing with the AD7798BRUZ, ensure proper decoupling of the AVDD and DVDD supplies with 0.1 µF and 10 µF capacitors, and place the reference decoupling capacitor close to the REFIN pins. The SPI interface should be isolated if the ADC is remote from the controller to avoid ground loops.
Drop-in alternatives for AD7798BRUZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD7798BRUZ (same form factor and footprint) — differing in Package, Resolution, Supply Voltage, Reference Type, Number of Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7799BRUZ
✅ Drop-In✓ In Stock
$5.41 / Unit
View Datasheet →AD7781BRUZ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.06 / Unit
View Datasheet →ADS1112IDRCT
✅ Drop-In📋 Reference alternative (not in catalog)
TC3405VQRTR
✅ Drop-In📋 Reference alternative (not in catalog)
ADS1112DRCR
✅ Drop-In📋 Reference alternative (not in catalog)
AD7798BRUZ Maximum Ratings & Electrical Characteristics
| Resolution | 16 Bit |
| Number of Channels | 3 Input |
| Architecture | Sigma-Delta |
| Output Data Rate | 4.17 Hz to 470 Hz |
| RMS Noise | 1.5 µV at 4.17 Hz |
| Supply Voltage | 2.7V to 5.25V |
| Supply Current | 400 µA typ |
| Power-Down Current | 1 µA max |
| On-Chip In-Amp Gain | Up to 128 |
| Interface | SPI |
| Package | 16-Lead TSSOP |
| Operating Temperature | -40°C to +105°C |
| RoHS | Compliant |
| MSL Level | 1 (Unlimited) |
| ECCN | EAR99 |
AD7798BRUZ Pin Configuration
| Pin 1 | SCLK — Serial clock input for SPI interface |
| Pin 2 | DIN — Serial data input for SPI interface |
| Pin 3 | DOUT — Serial data output for SPI interface |
| Pin 4 | CS — Chip select input (active low) |
| Pin 5 | GND — Ground |
| Pin 6 | AVDD — Analog power supply |
| Pin 7 | DVDD — Digital power supply |
| Pin 8 | REFIN(+) — Positive reference input |
| Pin 9 | REFIN(-) — Negative reference input |
| Pin 10 | AIN1(+) — Positive analog input 1 |
| Pin 11 | AIN1(-) — Negative analog input 1 |
| Pin 12 | AIN2(+) — Positive analog input 2 |
| Pin 13 | AIN2(-) — Negative analog input 2 |
| Pin 14 | AIN3(+) — Positive analog input 3 |
| Pin 15 | AIN3(-) — Negative analog input 3 |
| Pin 16 | PWRDN — Power-down input (active low) |
Typical Applications
AD7798BRUZ is suitable for 6 applications: Temperature Measurement, Pressure and Strain Gauge Sensing, Battery Monitoring, Weigh Scales, Process Control, Portable Instrumentation.
Temperature Measurement
The AD7798BRUZ is ideal for temperature measurement with RTDs and thermocouples. Its on-chip in-amp with gain up to 128 allows direct connection to low-level sensor outputs, while the 16-bit resolution and low noise (1.5 µV RMS) ensure accurate temperature readings. The low power consumption (400 µA) makes it suitable for battery-powered temperature loggers. The SPI interface simplifies data transfer to a microcontroller for processing and display.
Recommended
Pressure and Strain Gauge Sensing
The AD7798BRUZ is well-suited for pressure and strain gauge applications due to its low noise and programmable gain. The on-chip in-amp can amplify small bridge outputs, and the low-side power switch can be used to excite the bridge. The 16-bit resolution provides sufficient dynamic range for most industrial pressure sensors. Its low power consumption is beneficial for portable pressure monitors. The SPI interface allows easy integration with microcontrollers for data logging and control.
Recommended
Battery Monitoring
The AD7798BRUZ is used in battery monitoring systems to measure voltage and current with high accuracy. Its low supply current (400 µA) and power-down mode (1 µA) help extend battery life in portable devices. The three differential inputs can measure battery voltage, current shunt voltage, and temperature simultaneously. The internal reference and clock reduce external component count, simplifying design. The SPI interface enables communication with a host controller for state-of-charge estimation.
Recommended
Weigh Scales
The AD7798BRUZ is commonly used in weigh scale applications due to its high resolution and low noise. The on-chip in-amp with gain up to 128 can amplify the small output from a load cell, and the low-side power switch can drive the bridge excitation. The 16-bit resolution provides adequate accuracy for many industrial and consumer scales. The low power consumption is ideal for battery-operated scales. The SPI interface allows easy calibration and data readout.
Recommended
Process Control
The AD7798BRUZ is suitable for process control systems requiring precise analog-to-digital conversion. Its three differential inputs can monitor multiple sensors, and the programmable gain allows adaptation to various signal levels. The industrial temperature range (-40°C to +105°C) ensures reliable operation in harsh environments. The SPI interface enables communication with PLCs or microcontrollers for closed-loop control. The low power consumption is beneficial for remote or battery-powered field instruments.
Recommended
Portable Instrumentation
The AD7798BRUZ is ideal for portable instrumentation due to its low power consumption and small TSSOP-16 package. It operates from a single 2.7V to 5.25V supply, making it compatible with battery-powered designs. The power-down mode (1 µA) extends battery life during idle periods. The on-chip reference and clock reduce external components, saving board space. The SPI interface allows connection to low-power microcontrollers for data logging and display.
Recommended
Recommended Products Summary
Engineering reference data for AD7798BRUZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7799BRUZ | AD7781BRUZ | ADS1112IDRCT | TC3405VQRTR |
|---|---|---|---|---|---|
| Package | 16-Lead TSSOP | 16-Lead TSSOP | 16-Lead TSSOP | 16-Lead TSSOP | 16-Lead TSSOP |
| Brand | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Microchip Technology |
| Resolution | 16 Bit | 24 Bit | 24 Bit | 16 Bit | 16 Bit |
| Number of Channels | 3 | 3 | 1 | 4 | 4 |
| Interface | SPI | SPI | SPI | I2C | SPI |
| Supply Voltage | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.5V | 2.7V to 5.5V |
| Supply Current | 400 µA | 400 µA | 250 µA | 240 µA | 400 µA |
Key Differentiators
- On-chip in-amp with gain up to 128 (vs ADS1112IDRCT)
- Lower power consumption (vs TC3405VQRTR)
- Higher resolution alternative available (vs AD7799BRUZ)
Design Notes
Decouple AVDD and DVDD with 0.1 µF and 10 µF capacitors placed close to the pins. Use separate analog and digital ground planes to minimize noise coupling. The AD7798BRUZ operates from 2.7V to 5.25V; ensure the supply is clean and stable for optimal performance.
Place the reference decoupling capacitor close to the REFIN pins. Use a 0.1 µF capacitor for REFIN(+) and REFIN(-) to ground. For best noise performance, use a low-ESR ceramic capacitor. Keep the analog input traces short and shielded to avoid interference.
Ensure the SPI interface is properly isolated if the ADC is remote from the controller to avoid ground loops. Use series resistors on SPI lines to reduce ringing. Also, avoid floating unused analog inputs; tie them to a common-mode voltage or ground to prevent noise pickup.
Compliance Information
RoHS3 compliant, REACH unaffected, MSL 1 (Unlimited) per PartGenie. Halogen free per GlobalSpec.