Reference voltage accuracy usually looks stable in the lab. Then the temperature chamber starts moving. In automotive environments where sensors feed motor inverters, BMS units, and braking systems, small voltage drift compounds quickly once analog signals are digitized. The A/D converter only reports what it is given. ABLIC’s S-19760/1 Series target that specific pressure point with ±0.1% initial accuracy and a temperature coefficient down to ±20ppm per degree Celsius, and that combination changes how much calibration margin needs to be reserved elsewhere.
Voltage Reference Stability Under Automotive Temperature Cycling
In EV and HEV inverter systems, current, voltage, and position sensors rely on the stability of the reference node feeding the A/D converter. If the reference shifts across the -40°C to +125°C automotive range, every digital reading inherits that error. ABLIC specifies its tightest variants at ±0.1% output accuracy at 25°C, with temperature coefficients as low as ±10ppm per degree in narrower ranges and ±20ppm per degree across the full automotive span. That reduces drift across real operating cycles rather than only at nominal temperature.
Output options include common reference levels such as 2.048V, 2.5V, 3.0V, 3.3V, 4.096V, and 5.0V. The 2.048V variant is particularly relevant in precision ADC architectures where binary scaling aligns cleanly with that value. When output noise is limited to 28µVrms at 2.048V, the reference contributes less uncertainty to the conversion result, especially in high-resolution sensing chains.
Noise, Shunt Current, and Multi-Circuit Referencing
Shunt references are often chosen for simplicity, but they can become limiting when multiple circuits need to share a stable node. The S-19761 variant supports shunt currents up to 30mA, allowing a single reference device to serve more than one converter or comparator stage. That reduces the number of discrete references on the board, which in automotive layouts directly affects routing density and thermal distribution.
The integrated filter behavior and low output noise matter when ADC resolution increases beyond 12 or 14 bits. At that point, tens of microvolts begin to influence effective resolution. Keeping noise at 28µVrms limits how much averaging or digital filtering is required downstream.
Package Density and Mounting Constraints
Automotive ECUs and inverter control boards are rarely spacious. In addition to the standard SOT-23-3 outline, ABLIC offers an HSNT-8(1616)B package measuring 1.6mm by 1.6mm with a thickness of 0.41mm. That footprint allows placement close to the ADC input network, reducing trace exposure and potential coupling from nearby switching nodes.
The device supports ceramic output capacitors with modest minimum values, 0.22µF for the S-19760 and 0.68µF for the S-19761, which simplifies stability considerations in compact layouts.
Automotive Qualification and System-Level Implications
The series is designed for automotive temperature testing and is planned to meet AEC-Q100 requirements, with PPAP support indicated. In practical terms, this positions the reference for inverter control, battery management systems, on-board chargers, DC-DC converters, and traditional engine or suspension control units where sensor precision feeds directly into control stability.
When sensor counts increase and digitization spreads deeper into vehicle subsystems, the reference node becomes less of a background component and more of a limiting factor. Tight initial accuracy combined with low temperature drift reduces the need to compensate digitally for analog instability. Sometimes that margin is what keeps the control loop predictable.
Learn more and read the original announcement at www.ablic.com
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