ADS1115IDGSR 16-Bit I2C ADC for Precision Analog Measurement

ElecSuppliers ApplicationsAug 22, 2026

ADS1115IDGSR is a precision 16-bit analog-to-digital converter designed for embedded systems that need to measure analog signals with more resolution than a typical microcontroller ADC can provide.

The device combines a delta-sigma ADC architecture, programmable gain amplifier, internal voltage reference, oscillator, comparator and I2C interface in a compact 10-pin VSSOP package. It supports four single-ended inputs or two differential input measurements and provides programmable conversion rates from 8 SPS to 860 SPS.

This combination makes ADS1115IDGSR particularly useful for sensor interfaces, battery monitoring, industrial measurement, instrumentation and other applications where accurate low-speed analog measurement is more important than high sampling speed.

ADS1115IDGSR Specifications

ADS1115IDGSR provides 16-bit resolution with a maximum data rate of 860 samples per second.

The device operates from a 2.0V to 5.5V supply and has four multiplexed analog inputs. These inputs can be configured as four single-ended channels or two differential channels.

An internal programmable gain amplifier provides selectable full-scale input ranges from ±256mV to ±6.144V.

The device also integrates an internal voltage reference and oscillator, reducing the number of external components required for a basic ADC implementation.

ADS1115IDGSR I2C Interface

ADS1115IDGSR communicates with a microcontroller through an I2C-compatible interface.

This is useful in embedded designs where ADC measurements need to be transferred to a processor without consuming a large number of GPIO pins.

The device provides four selectable I2C addresses, allowing multiple ADS1115 devices to share the same bus when additional analog channels are required.

A system can therefore expand its analog measurement capability without dedicating a separate SPI bus or multiple chip-select signals to every ADC.

ADS1115IDGSR Four-Channel ADC

The four-channel configuration is one of the main advantages of ADS1115IDGSR.

The internal multiplexer allows the four analog inputs to be measured individually as single-ended channels.

For example, a controller could use the four inputs for monitoring supply voltage, temperature-sensor output, current-sense voltage and another analog feedback signal.

The channels are multiplexed rather than converted simultaneously, so applications requiring simultaneous sampling of multiple signals should use an ADC designed specifically for that purpose.

ADS1115IDGSR Differential Input

ADS1115IDGSR can also measure differential signals.

Two differential input pairs can be selected through the internal multiplexer.

Differential measurement is useful when the signal of interest is a small voltage difference between two nodes rather than an absolute voltage referenced directly to ground.

This can be valuable for current sensing, bridge sensors and other low-level analog measurements.

The input configuration should be selected according to the signal source and the expected common-mode voltage.

ADS1115IDGSR Programmable Gain

The integrated PGA allows the input range to be adjusted according to the amplitude of the signal being measured.

The selectable full-scale ranges include ±256mV, ±512mV, ±1.024V, ±2.048V, ±4.096V and ±6.144V.

A smaller full-scale range can make better use of the ADC's resolution when measuring a small signal.

For example, a sensor producing only a few hundred millivolts can be measured using a more appropriate PGA setting instead of wasting much of the ADC range on a signal that never approaches the supply voltage.

The selected input range must still respect the device's absolute input and supply constraints.

ADS1115IDGSR 16-Bit Resolution

The 16-bit resolution of ADS1115IDGSR provides a much finer digital representation than a typical 10-bit ADC.

This does not automatically mean that every application will achieve true 16-bit measurement accuracy.

Noise, input source impedance, PCB layout, reference stability, sensor characteristics and the selected data rate all affect the usable resolution.

For precision measurement systems, designers should evaluate noise and effective resolution rather than relying on the nominal bit count alone.

ADS1115IDGSR Data Rate

The programmable data rate ranges from 8 SPS to 860 SPS.

Lower conversion rates can be useful when the application prioritizes noise performance and stable measurement.

Higher rates reduce the time required to obtain a new conversion and are more appropriate for signals that change relatively quickly.

Because ADS1115IDGSR is intended primarily for precision measurement rather than high-speed waveform acquisition, it is better suited to slowly changing sensor and control signals than to high-frequency audio or fast transient capture.

ADS1115IDGSR Single-Cycle Conversion

ADS1115IDGSR supports single-cycle settling.

This is useful when the application switches between different input channels or PGA settings and needs a conversion from the newly selected configuration.

A microcontroller can configure the desired channel, start the conversion and retrieve the result through I2C.

This makes the ADC convenient for systems that periodically measure several different sensors.

The firmware should still account for the selected conversion rate when scheduling measurements.

ADS1115IDGSR Internal Voltage Reference

The device includes an internal low-drift voltage reference.

An integrated reference simplifies the hardware because the basic ADC circuit does not require a separate external reference IC.

This is particularly useful in compact sensor boards where component count and PCB area are limited.

For applications with unusually demanding long-term accuracy or reference requirements, the complete error budget should be evaluated to determine whether the internal reference meets the system target.

ADS1115IDGSR Internal Oscillator

An internal oscillator provides the conversion timing for the ADC.

This removes the need for an external clock source in a standard implementation.

The combination of internal reference and oscillator helps keep the external circuit simple.

A microcontroller therefore needs to provide the I2C communication and configuration commands without having to generate a dedicated ADC clock.

ADS1115IDGSR Comparator

ADS1115IDGSR also includes a programmable digital comparator.

The comparator can be configured for threshold detection, which can be useful when the system needs to detect whether a measured signal has moved above or below a specified level.

For example, an embedded controller can use the ADC for normal voltage measurement while also using the comparator function to identify an overvoltage or undervoltage condition.

This can reduce the need for an additional discrete threshold detector in some designs.

ADS1115IDGSR for Voltage Measurement

A common application is measuring analog supply voltages.

The input voltage can be reduced through a resistor divider before being connected to the ADC input.

The microcontroller reads the converted value through I2C and calculates the original voltage using the divider ratio.

This approach can be used for battery monitoring, power-supply diagnostics and embedded equipment status monitoring.

The resistor values should be selected carefully because divider resistance affects ADC input behavior, noise susceptibility and power consumption.

ADS1115IDGSR for Current Sensing

ADS1115IDGSR can also be used in current-monitoring circuits.

A small shunt resistor produces a voltage proportional to load current.

The ADC can measure the voltage across the shunt using a differential configuration.

The PGA can then be selected to match the relatively small signal generated by the shunt.

For higher-current systems, the shunt voltage may be only a few millivolts or tens of millivolts, so PCB layout, common-mode voltage and noise become important design considerations.

ADS1115IDGSR for Temperature Sensors

Many temperature sensors produce relatively slow analog output signals.

This makes them a good match for the ADS1115's relatively low maximum sampling rate.

The ADC can periodically measure a thermistor circuit, analog temperature sensor or other voltage-output sensor.

Because temperature changes slowly compared with many electronic signals, the system can use lower data rates while focusing on measurement stability.

The MCU can then convert the ADC reading into a temperature value according to the selected sensor circuit.

ADS1115IDGSR for Industrial Sensors

Industrial sensors often generate analog signals that must be digitized by a controller.

ADS1115IDGSR can be used when the signal bandwidth is relatively low and additional resolution is useful.

Potential applications include pressure measurement, flow monitoring, level sensing and analog process feedback.

The actual interface design depends on the sensor output range.

Industrial signals such as 0–10V or 4–20mA generally require additional signal-conditioning circuitry before being connected to the ADC inputs.

ADS1115IDGSR Power Supply

The ADC operates from a 2.0V to 5.5V supply.

This allows it to be used with many 3.3V and 5V embedded systems.

The supply should be properly decoupled close to the device.

Analog measurement performance can be affected by supply noise, so switching regulators, digital clocks and other noisy circuits should be considered during PCB design.

A clean power path is especially important when measuring small differential signals.

ADS1115IDGSR Package

ADS1115IDGSR uses a 10-pin VSSOP package.

The package is approximately 3 mm × 4.9 mm, making it suitable for compact sensor and measurement PCBs.

The device family is also available in smaller package options, but the exact package suffix must be checked when designing a replacement PCB.

For ADS1115IDGSR specifically, the package and pin configuration should match the existing footprint.

ADS1115IDGSR PCB Layout

Precision ADC performance depends heavily on PCB layout.

Analog input traces should be kept away from noisy digital signals where practical.

The I2C lines and high-speed switching nodes should not be routed unnecessarily close to sensitive analog inputs.

The supply bypass capacitor should be placed close to the ADC power pins.

For differential measurements, the two input traces should be routed together and exposed to similar interference conditions.

A clean ground strategy is also important when the ADC shares a PCB with switching power supplies, motors or high-current digital circuits.

ADS1115IDGSR with Microcontrollers

ADS1115IDGSR can be connected to microcontrollers that provide an I2C interface.

The MCU configures the ADC registers, selects the input channel and PGA range, starts conversions and reads the resulting digital data.

This architecture separates analog measurement from the MCU's internal ADC resources.

It can be particularly useful when the built-in ADC has insufficient resolution, too few channels or inadequate input-range flexibility.

ADS1115IDGSR vs MCU ADC

Many microcontrollers already include ADC peripherals, so an external ADC is not always necessary.

ADS1115IDGSR becomes attractive when the application needs 16-bit resolution, differential measurement, programmable gain or a dedicated precision ADC.

The external device also allows the analog measurement section to be upgraded without changing the main MCU.

For a simple potentiometer or button-level measurement, an MCU's internal ADC may be sufficient.

For low-level sensors or precision voltage monitoring, the additional capabilities of ADS1115IDGSR can justify the extra component.

ADS1115IDGSR Replacement

When selecting an ADS1115IDGSR replacement, designers should compare more than the 16-bit resolution.

Important parameters include the number of input channels, differential-input configuration, PGA ranges, I2C compatibility, data rates, supply voltage, package and comparator functions.

A replacement ADC with the same resolution but a different input architecture may require changes to both the PCB and firmware.

For an existing design, the I2C address configuration and register map should also be checked.

ADS1115IDGSR Alternative

Several types of ADC can be considered as alternatives depending on the application.

A 12-bit ADC may be sufficient when lower resolution is acceptable and faster sampling is more important.

A higher-speed SAR ADC may be preferable for rapidly changing signals.

A dedicated current or voltage monitor may be better when the application requires integrated shunt measurement and power monitoring functions.

ADS1115IDGSR is most attractive when the design needs a compact, low-power, 16-bit ADC with flexible input configuration and I2C communication.

Choosing ADS1115IDGSR

ADS1115IDGSR is well suited to embedded designs that need precision analog measurement without adding a complicated high-speed ADC subsystem.

Its 16-bit resolution, four single-ended or two differential inputs, programmable gain, internal reference, internal oscillator and I2C interface make it flexible for sensor and monitoring applications.

The device is particularly appropriate for slowly changing analog signals such as temperature, pressure, battery voltage and current-sense measurements.

For a new design, the main factors to evaluate are input range, PGA setting, sampling rate, noise, sensor interface and PCB layout.

For a replacement project, the complete electrical characteristics, package, I2C behavior and register configuration should be checked before selecting another ADC.