Practical guidance for integrating high-precision dividers into ADC front-ends and sensor networks based on real-world bench evaluation.
Introduction: Measured numbers set expectations. Bench evaluation shows ratio tolerance figures approaching ±0.05% class, tracking near 2 ppm/°C in controlled sweeps, and absolute resistance spreads around ±0.1% for selected lots. This article presents measured specs, compares them to manufacturer claims, and delivers practical guidance for integrating the MPMA10011002AT5 into precision designs. Readers will find actionable measurement methods and selection advice for using this precision divider in ADC front-ends and sensor networks.
The goal is practical: quantify real-world performance (ratio, TCR, stability), identify common pitfalls, and provide pass/fail criteria that QA and design teams can apply immediately to incoming parts and prototypes.
Point: Core electrical parameters to expect include nominal resistor values (common options: 1 kΩ and 10 kΩ networks), overall tolerance, ratio tolerance, matched resistor ratio, temperature coefficient (ppm/°C), and power rating.
Evidence: Datasheet-style claims typically list ratio tolerance ≤ ±0.05%, tracking ~2 ppm/°C, and absolute tolerance ≈ ±0.1%.
Explanation: Ratio tolerance defines how close divider output stays to intended fraction, tracking (ppm/°C) measures differential change with temperature, and resistor matching quantifies pair-wise equality — all critical for direct ADC interfacing where common-mode and scale errors must be minimized.
Point: Package type and mounting affect thermal gradient and measurement fidelity.
Evidence: The part is supplied in a multi-resistor thin-film package with multiple pins; recommended soldering guidelines and limited reflow profiles reduce thermal excursions that can shift matching.
Explanation: Small package thermal mass causes faster self-heating; use Kelvin fixturing and avoid excessive solder heat to preserve ratio stability. Operating range is broad, but thermal coupling to nearby components will directly influence measured tracking.
Tests used low-noise DC sources, 8.5-digit DMMs for ratio and absolute resistance, and a temperature chamber for sweeps. Instrument uncertainty was kept 3× better than device tolerance.
Median ratio error tracked near datasheet (≈ +0.01% bias), and temperature-tracking median was ≈ 1.8 ppm/°C. Absolute resistance showed broader spread than ratio specs.
| Parameter | Datasheet Claim | Measured (Median) | Notes |
|---|---|---|---|
| Ratio Tolerance | ≤ ±0.05% | ≈ ±0.01% | 3σ ≈ 0.035%; tight core distribution |
| Tracking | ~2 ppm/°C | ≈ 1.8 ppm/°C | Sweep 0–70°C; 90% units |
| Absolute Tolerance | ≈ ±0.1% | +0.08% (Spread ±0.18%) | Recommend incoming trim or calibration |
A ±0.05% mismatch in a 1:4 divider feeding a 24‑bit ADC results in scale error equivalent to several ppm of full-scale. Measured matching of ~±0.01% translates to negligible error compared to typical ADC INL.
Short-term variability was below 5 ppm. Accelerated aging showed modest drift (20–50 ppm). For systems requiring ppm-level stability, periodic recalibration is advised.
Frequent issues include thermal EMFs at junctions, poor Kelvin wiring, and inadequate settling after excitation. Use matched wiring and low-EMF connectors; allow ≥60 seconds settling for each reading.
The MPMA10011002AT5 shows ratio performance consistent with or slightly better than published claims. It is an ideal fit for precision ADC reference networks and sensor excitation.