ADS1015

The ADS1015 is a precision, low-power 12-bit delta-sigma analog-to-digital converter from Texas Instruments, built around an input multiplexer, a programmable gain amplifier, an internal reference, an internal 1 MHz oscillator, a 12-bit converter and a programmable comparator, all controlled over I2C. It offers four single-ended or two differential input channels, programmable data rates from 128 SPS to 3300 SPS, single-cycle settling after a channel or gain change, and continuous or single-shot conversion modes. Supply range is 2.0 V to 5.5 V; operating current is 150 µA typical and 300 µA maximum in continuous conversion, and power-down current is 0.5 µA typical with 2 µA maximum.

The PGA gives the part its flexibility. Full-scale ranges of ±6.144 V, ±4.096 V, ±2.048 V, ±1.024 V, ±0.512 V and ±0.256 V correspond to gains of 2/3 down to 16, letting the same board measure a 12 V battery divider and a millivolt-level shunt or thermocouple amplifier output. One subtlety worth knowing: TI deliberately does not publish an absolute internal reference voltage, because the architecture does not use a conventional bandgap; the device is specified directly by full-scale range, and no external reference can be connected. Absolute accuracy therefore comes from the gain-error specification (0.05 % typical, 0.25 % maximum) and gain drift (5 ppm/°C to 40 ppm/°C depending on range), while INL is 0.5 LSB typical. Analog inputs are limited to VDD + 0.3 V, and the input impedance is switched-capacitor in nature — 4.9 MΩ differential at the ±2.048 V range and about 10 MΩ common-mode at ±6.144 V — so keep source impedances below a few kilohms or allow extra settling.

The I2C interface supports standard, fast and high-speed modes up to 3.4 MHz, and the ADDR pin selects one of four addresses by strapping to GND, VDD, SDA or SCL (0x48 to 0x4B), so up to four converters can share a bus. The ALERT/RDY pin doubles as a programmable comparator output in traditional or window mode — useful for over/under-voltage alarms without polling — or as a conversion-ready flag in single-shot operation. Packages are the 10-pin VSSOP (DGS), 10-pin SOT (DYN) and leadless X2QFN-10 (RUG), all specified from −40 °C to +125 °C.

Typical uses include battery and current monitoring, portable instrumentation, factory automation and process control, thermistor and RTD measurement, and as the standard analog expansion for single-board computers. The ADS1115 is the pin- and register-compatible 16-bit sibling running up to 860 SPS, and the ADS1013/ADS1014 are reduced-feature versions with one channel. Sourcing: TI's DGS (VSSOP-10) and DYN (SOT-10) parts ship in 2,500-piece reels, with breakout modules widely available. MOQ is 1 reel or 100 pcs cut tape, dispatching in 1-2 days from Shenzhen stock; the TI authorized channel is 5-10 days. Counterfeit material appears mostly as remarked ADS1013 or ADS1014 die sold as ADS1015, and as ADS1115 parts relabeled downward — identify them by reading the conversion register behaviour: an ADS1015 returns data in the upper 12 bits with four zeros, while an ADS1115 returns full 16-bit codes, and an ADS1013 ignores the multiplexer field entirely.