From 7ca213bd4b23c976f7fd83c99f40b6def2ab4ea6 Mon Sep 17 00:00:00 2001 From: Denis Chevalier Date: Tue, 11 Aug 2026 11:28:45 +0200 Subject: add ratio-stability-principle chart --- module-design.typ | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/module-design.typ b/module-design.typ index 4234f3d..c295094 100644 --- a/module-design.typ +++ b/module-design.typ @@ -2145,18 +2145,21 @@ This single drift component alone exceeds the Metrologic drift budget for two resistors with tempcos $alpha_A$ and $alpha_B$: $ - (R_A (T)) / (R_B (T)) = (R_(A 0) (1 + alpha_a Delta T)) / (R_(B 0) (1 + alpha_B Delta T)) approx (R_(A 0))/(R_(B 0) [ 1 + (alpha_A - alpha_B) Delta T]) + (R_A (T)) / (R_B (T)) = (R_(A 0) (1 + alpha_A Delta T)) / (R_(B 0) (1 + alpha_B Delta T)) approx (R_(A 0))/(R_(B 0) [ 1 + (alpha_A - alpha_B) Delta T]) $ The net ratio tempco is the tracking mistmatch $Delta alpha = alpha_A - alpha_B$. When matched resistors from the same batch are placed in close thermal -proximity on the PCB, their tracking mismatch drops be $lt qty(1, "ppm per celsius")$ -even if individual tempcos are $qty(25, "ppm per celsius").$ +proximity on the PCB, their tracking mismatch drops would be +$lt qty(1, "ppm per celsius")$ even if individual tempcos are +$qty(25, "ppm per celsius").$ Furthermore, monolithic thin-film resistor networks (multiple laser-trimmed resistors on a single ceramic substrate) achieve ratio tracking tempcos $lt qty(0.2, "ppm per celsius")$ ($qty(200, "ppb per celsius")$). +#include "charts/ratio-stability-principle.typ" + ====== Scaling law - Absolute single-ended resistance drift scales linearly with temperature @@ -2181,6 +2184,8 @@ $lt qty(0.2, "ppm per celsius")$ ($qty(200, "ppb per celsius")$). Periodically correct baseline gains against the system reference standard, which is ovenized to eliminate reference tempco effects. +===== Resistor aging and load life + == Error compensation strategies == Advanced compensation topologies -- cgit