Texas Instruments ADS1115IDGSR: PCB footprint and gate checks

The Texas Instruments ADS1115IDGSR is a 16-bit four-channel delta-sigma ADC from Texas Instruments. Its package or board interface is 10-pin VSSOP, and its relevant electrical envelope is 2.0–5.5 V; analog inputs must stay within GND/VDD absolute limits. It communicates or connects through I²C with four addresses and ALERT/RDY. Those fields belong together: substituting a familiar family name while changing package, voltage, sensing port, mount style, current class, or interface behavior can leave a PCB that passes ordinary net checks and still cannot be assembled or function safely.

ADS1115 provides a programmable-gain muxed ADC at up to 860 samples/s, but its differential range does not permit inputs outside the supply rails.

Common uses include precision slow sensor acquisition and bridge and battery measurements. Start with the manufacturer drawing and recommended application, then record the exact ordering suffix alongside the KiCad symbol and footprint. This makes the library evidence reviewable when the part is re-sourced months later.

• Use the exact package drawing, pin-one convention, and exposed-pad guidance. Pay special attention to mechanical, thermal, magnetic, or analog keepouts specific to the sensing principle.
• Protect sensitive inputs and sensing surfaces during assembly and enclosure design; a valid solder footprint alone does not guarantee a valid measurement path.

Add per-channel RC filtering and protection that fits source impedance and settling, set address, and use ALERT/RDY for deterministic sampling when needed.

• Place the device where it measures the intended stimulus rather than board noise. Keep switching currents, heat, magnetic materials, vibration, and digital clocks away according to the sensor's mechanism.
• Provide quiet supplies, defined address/mode pins, correct pull-ups or analog filtering, and a calibration or test method that survives manufacturing variation.

Put the support components where their current, thermal, optical, RF, or measurement loops are actually short—not merely where ratsnest lines look tidy. Confirm pin one from the package view used in the datasheet, distinguish top view from mating face or bottom view, and check mask, paste, drill, courtyard, enclosure, and rework access independently. A correct copper pad pattern can still be a bad production footprint when the sensing opening, connector latch, exposed pad, thermal path, or cable volume is wrong.

MakeIRL’s release gate should not stop at “the symbol has the right number of pins.” For this part, a useful gate review combines ERC/DRC with the following package- and function-specific evidence:

1. Check package, orientation, supply and I/O range, decoupling, interface straps, interrupts or data-ready, and all sensing-specific external components.
2. Check the physical stimulus path and verify copper, mounting hardware, magnets, heat sources, strain, or contamination cannot invalidate it.
3. Check orderable suffix, range, accuracy, temperature grade, calibration state, and lifecycle in the BOM.
4. For Texas Instruments ADS1115IDGSR, check VSSOP-10 footprint, address strap, input absolute limits versus PGA range, reference architecture, RC settling, ALERT, and I²C pull-ups.

Then run ERC and DRC, refill zones, and inspect the fabrication and assembly outputs. Cross-probe the exact pads named by any finding, compare the BOM MPN with the footprint and electrical limits above, and verify that a real cable, enclosure, antenna, sensor stimulus, load, or thermal path can be tested on the assembled unit. An exclusion is evidence that someone dismissed a marker; it is not evidence that the underlying condition was resolved.

The most expensive errors are usually plausible: a footprint from a sibling package, a breakout-board voltage copied to the bare IC, a headline current used without thermal analysis, or a connector family selected by pitch alone. For Texas Instruments ADS1115IDGSR, review these failure modes explicitly:

• Confusing ±6.144 V full-scale code with a true ±6.144 V input range can over-voltage an ADS1115 powered from 3.3 V.
• Selecting a breakout board by familiar name while the production IC has a different voltage, address, filter, or required support circuit.
• Finishing schematic integration without defining how the sensor will be calibrated or functionally tested after assembly.

Sourcing note. Specify ADS1115IDGSR from TI; ADS1015 is footprint-related but only 12-bit and has different timing. The approved vendor list should preserve manufacturer, full suffix, package, voltage/range/accuracy grade, lifecycle, and mating or external components. An alternate is real only after its datasheet, land pattern, electrical behavior, firmware assumptions, and assembly process have all been compared—not because a distributor search places it in the same parametric row.