ADS1115 16-bit ADC: specs and pinout
16-bit I2C analog-to-digital converter with four single-ended or two differential inputs and a programmable gain amplifier.
Specs
| Spec | Value | Source |
|---|---|---|
| Supply voltage VDD | 2.0 V to 5.5 V | source Features (p.1) |
| Resolution | 16 bit | source Features (p.1) |
| Data rate | 8 SPS to 860 SPS | source Features (p.1); Electrical Characteristics, data rate (p.5) |
| Inputs | 4 single-ended or 2 differential (ADS1115) | source Features (p.1); pin table (p.3) |
| Full-scale input range (PGA) | +/-0.256 V to +/-6.144 V | source Electrical Characteristics, analog inputs (p.4) |
| Analog input voltage range | GND - 0.3 V to VDD + 0.3 V (no more than VDD + 0.3 V on the inputs) | source Absolute Maximum Ratings (p.4) and footnote 2 (p.4) |
| Continuous input current | +/-10 mA (any pin except supplies) | source Absolute Maximum Ratings (p.4) |
| I2C address (ADDR pin to GND) | 1001000 | source Address pin table (p.20) |
| I2C address (ADDR pin to VDD) | 1001001 | source Address pin table (p.20) |
| I2C address (ADDR pin to SDA) | 1001010 | source Address pin table (p.20) |
| I2C address (ADDR pin to SCL) | 1001011 | source Address pin table (p.20) |
Power
| Value | Source | |
|---|---|---|
| Supply | VDD 2.0-5.5 V (chip ratings) | source Features (p.1); typical current not given |
Chip pins
These are the pins of the chip on the module, from the chip datasheet. The module's own header may label or expose them differently. Module header labels come from the Compoden listing, not an official module schematic.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| VDD | Power supply; connect a 0.1 uF decoupling capacitor to GND | 2.0-5.5 V; absolute max 7 V | source Table 4-1 Pin Functions (p.3); Section 5.1 Absolute Maximum Ratings (p.4) | |
| GND | Analog ground | 0 V | source Table 4-1 Pin Functions (p.3) | |
| SDA | Serial data input and output; connect to VDD with a pullup resistor | Digital input absolute max GND - 0.3 V to 5.5 V | source Table 4-1 Pin Functions (p.3); Section 5.1 Absolute Maximum Ratings (p.4) | |
| SCL | Serial clock input; connect to VDD with a pullup resistor | Digital input absolute max GND - 0.3 V to 5.5 V | source Table 4-1 Pin Functions (p.3); Section 5.1 Absolute Maximum Ratings (p.4) | |
| ADDR | I2C target address select (digital input) | Digital input absolute max GND - 0.3 V to 5.5 V | GND = 1001000, VDD = 1001001, SDA = 1001010, SCL = 1001011. | source Table 4-1 Pin Functions (p.3) |
| ALERT/RDY | Comparator output or conversion ready; open-drain, connect to VDD with a pullup | Digital input absolute max GND - 0.3 V to 5.5 V | Not named in the listing's pin list. | source Table 4-1 Pin Functions (p.3) |
| AIN0, AIN1, AIN2, AIN3 | Analog inputs 0 to 3 (single-ended or differential) | Absolute max GND - 0.3 V to VDD + 0.3 V | The PGA full-scale range of +/-6.144 V does NOT allow inputs above VDD + 0.3 V. Not named in the listing's pin list. | source Table 4-1 Pin Functions (p.3); Section 5.1 Absolute Maximum Ratings (p.4) |
Common mistakes
- Applying an input above VDD + 0.3 V: the analog inputs must stay between GND - 0.3 V and VDD + 0.3 V, even though the PGA range reaches 6.144 V (source)
- Guessing the address: the ADDR pin selects 1001000 (GND), 1001001 (VDD), 1001010 (SDA) or 1001011 (SCL) (source)
- Reading the resolution as 0-1023: the ADS1115 is a 16-bit converter (source)
What we could not confirm
- Pull-up resistor values are module-specific and not in the datasheet.
- Current draw and conversion timing are not given on this page.
- Module pinout (AIN0-AIN3, ALERT/RDY) is not covered here; chip datasheet only.
- Pin rows are the ADS1115 chip pins. Whether the module breaks out ALERT/RDY and AIN0-AIN3, the pull-up values, and the ADDR default are board facts with no official source (listing mentions ADDR, SDA, SCL, VDD, GND only).
- Listing says 'logic-level tolerant pins, so direct connection to 3.3V or 5V systems is safe'; the datasheet gives only an absolute maximum of 5.5 V on SDA/SCL/ADDR/ALERT and VDD + 0.3 V on analog inputs. At VDD = 3.3 V the analog inputs top out at 3.6 V. The 'safe' claim is not supported by the datasheet.
Sources
- link (TI ADS1113/4/5, SBAS444E, revised Dec 2024)
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