6. Frequently Asked Questions
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It varies by series. For example, a Murata TZB4R500AB10R00 is specified as 7–50 pF at 50 V DC. A smaller TZC3P300A110R00 covers 6.5–30 pF at 100 V. The overall TZ family spans roughly 0.5–120 pF. Always check the specific Murata datasheet for exact ranges and ratings.
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Stability depends on dielectric. Many Murata trimmers use NP0/C0G (±0–30 ppm/°C) for minimal drift, but larger-value parts may use N1500 or N750 ceramics (±300–750 ppm/°C). In practice, expect on the order of ±1–5% capacitance change over full temperature range. If precision tuning is needed, choose the C0G/NPO versions and minimize extreme conditions.
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Use a proper-sized screwdriver. Murata warns not to apply excessive torque: limit the adjustment force to about 4.9 N (500 gf) on the screw, and avoid twisting the board with more than about 9.8 N (1 kgf) total. Excessive force can damage the rotor or contacts. Adjust slowly, in small increments. If fixing the tuned position, use a non-corrosive locking paint (Murata recommends a chlorine- and sulfur-free lacquer). The case is typically sealed, but keep flux residue away from the slot.
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The term “green” refers to the component’s case color. Many trimmer capacitors are color-coded by range – green often indicates mid-range capacitance. For example, Farnell’s Multicomp Pro list shows a “Green” 50 pF trimmer with ±500 ppm/°C tempco. Murata’s green-body trimmers are similarly color-coded for quick ID of range (though always check the datasheet, as color coding schemes can vary).
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Some Murata trimmers (like the TZC and TZB series) have been discontinued. For example, Digi-Key notes “TZC3P300A110R00 is obsolete and no longer manufactured”. In that case, equivalents from other vendors can be used. For instance, Knowles Voltronics JZ or Johanson series trimmers cover similar ranges (e.g. JZ500 is 8–50 pF, 125 V). EstiSource can help identify and source suitable substitutes with matching specs.