Microchip Technology LR12LG-G

The LR12 regulates the voltage between VOUT and ADJ to a nominal 1.2 V. Two external resistors set the output voltage, while the typical 10-µA ADJ current contributes an additional term that must be included in precision calculations. The input must remain at least 12 V above the programmed output.

• Wide 13.2-V to 100-V operating input range.
• Adjustable 1.2-V to 88-V output supports many high-voltage bias rails.
• Only two setting resistors and an output capacitor are required for basic regulation.
• Integrated current limiting and overtemperature protection improve fault tolerance.
• Narrow eight-lead SOIC supports automated surface-mount assembly.

• Nominal 1.20-V reference with 5% tolerance.
• Typical ADJ-pin current: 10 µA.
• Current-limit range: 50 mA minimum to 100 mA maximum under specified conditions.
• Typical ripple rejection: 60 dB at 120 Hz for the datasheet test circuit.
• Stable with at least 100 nF output capacitance.
• Requires at least 500 µA total DC output current, including divider current and load.

The exact LR12LG-G orderable uses Microchip's LG eight-lead narrow SOIC package, corresponding to the catalog's 0.154-inch / 3.90-mm body-width description. The “G” suffix denotes a lead-free, RoHS-compliant package. Current Microchip documentation specifies 3300 devices per reel and shows the package marking LR12LG with date and traceability codes.

Select the feedback resistors using the LR12 output-voltage equation, including the ADJ-current term when accuracy matters. Maintain the specified minimum load current, place the output capacitor close to the device, and keep high-voltage creepage and clearance appropriate for the maximum applied voltage. Calculate dissipation from input-to-output voltage and load current before confirming a safe junction temperature.

A replacement must match the 100-V input capability, adjustable-output range, minimum 12-V headroom, load-current requirement, current-limit behavior, SOIC pinout, package dimensions, thermal limits, and stability conditions. Similar-looking eight-pin regulators are not pin-compatible by assumption. No internal alternative link is asserted because no exact API-confirmed match was established.

Microchip lists the LR12 family as In Production. The technical basis for this description is the Microchip LR12 data sheet DS20005735A, August 2022. That revision updated the LG-package reel quantity to 3300 devices to align with the current packaging specification.

• Offline and high-voltage SMPS startup circuits.
• Adjustable high-voltage constant-current sources.
• Industrial and motor-control bias supplies.
• Telecommunications power and control circuits.
• LED drivers and battery-powered high-voltage subsystems.

Verify the complete LR12LG-G order code, LR12LG package marking, eight-lead narrow-SOIC dimensions, pin-1 orientation, reel label, 3300-piece media quantity, Pb-free/RoHS designation, and lot traceability. Inspect leads and molding for handling damage or inconsistent re-marking before assembly.

Is LR12LG-G a fixed-output regulator? No. Two external resistors program the output from 1.2 V to 88 V.

Can it deliver 100 mA continuously? The data sheet gives 100 mA as the maximum current-limit value, not a guaranteed continuous-load rating. Continuous current depends on current-limit minimums and thermal conditions.

Why is a minimum load required? The divider and load together must draw at least 500 µA for regulation.

What capacitor is required? Use at least 100 nF effective output capacitance and verify voltage rating and bias derating.

Always validate resistor voltage ratings, high-voltage spacing, fault energy, capacitor derating, power dissipation, and junction temperature against the current Microchip documentation. This summary does not replace the data sheet.