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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

STMicroelectronics LM217MT

Name: LM217MT
Brand: STMicroelectronics
SKU: LM217MT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM217MT

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: TO-220-3

Datasheet:: LM217MT.pdf

Description:: IC REG LIN POS ADJ 500MA TO220

Quantity:: RFQ Add To RFQ list

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Inventory:4,390

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Product details

Overview

LM217MT from STMicroelectronics is a monolithic adjustable positive voltage regulator in DPAK package, delivering up to 500 mA output current with 1.2 V to 37 V adjustable output range, ±1% reference voltage accuracy, and integrated thermal/short-circuit protection-used in industrial power supplies requiring stable low-noise DC regulation.

For engineers reviewing the LM217MT datasheet, LM217MT pinout, LM217MT application, or LM217MT equivalent, this page provides verified pin functions, real-world load/line regulation values, thermal resistance data (R_thJA = 100 °C/W), noise performance (0.003% VO), and design-validated alternative options for adjustable linear regulator replacement.

Technical Context

The LM217MT operates as a floating three-terminal adjustable regulator with internal 1.25 V bandgap reference and feedback-controlled pass transistor. Its quiescent current returns entirely to the output terminal, enforcing a minimum load current (3.5–5 mA) to maintain regulation stability.

It features internal safe-area compensation, programmable current limiting via external resistor, and supports remote sensing by routing R1 near the regulator and R2 ground to the load. Ripple rejection improves to 80 dB at 120 Hz with a 10 µF CADJ capacitor.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage Range	1.2 V to 37 V - set by external resistive divider; enables single BOM part across multiple supply rails
Reference Voltage (V_REF)	1.25 V (min 1.2 V, max 1.3 V) - defines base gain ratio for output setting; tolerance directly impacts output accuracy
Max Output Current	500 mA (up to 1000 mA under limited VI–VO & T_J) - sufficient for mid-power analog/digital subsystems without heatsink at moderate dissipation
Line Regulation	0.01 %/V typ - ensures ≤0.37 V drift over full 40 V input differential at nominal load
Load Regulation	5 mV typ (VO ≤ 5 V) or 0.1 %/V typ (VO ≥ 5 V) - maintains tight output stability across 10–500 mA load swing
Adjust Pin Current (I_ADJ)	50–100 µA - low and stable; enables high-resistor-divider designs without significant error term
Output Noise	0.003 % of V_O (10 Hz–100 kHz) - ~300 µV RMS at 10 V output; suitable for noise-sensitive analog circuitry

Pinout & Package

DPAK (TO-252) package: surface-mount, thermally enhanced plastic case with exposed drain pad; footprint per ST's recommended 6.7 × 6.7 mm layout (Table 6); R_thJA = 100 °C/W, R_thJC = 8 °C/W.

Pin/Terminal	Circuit Role	Design Meaning
Input (IN)	Unregulated DC input supply connection	Accepts VI–VO up to 40 V differential; requires local bypass capacitor if >10 cm from bulk input cap
Output (OUT)	Regulated DC output node	Delivers adjusted voltage; carries full load current plus I_ADJ; ties to R1 top and load return
Adjust (ADJ)	Feedback reference node	Connected to junction of R1–R2 divider; senses 1.25 V above OUT; bypassing with 10 µF improves ripple rejection

Key Features

Feature	Design Value
Floating operation capability	Regulates based solely on VI–VO differential (≤40 V), enabling high-side or battery-ground-referenced configurations
Internal safe-area compensation	Prevents secondary breakdown during transient overload or start-up; eliminates need for external SOA protection
Thermal overload protection	Shuts down at T_J ≥ 125 °C; auto-recovery after cooldown; no latch-up behavior
Short-circuit protection	Current-limits to ~200 mA at VI–VO = 40 V; maintains safe dissipation without external foldback circuitry
Low adjustment pin current drift	I_ADJ variation ≤5 µA over line/load/temp - minimizes output error in high-R divider designs

Applications

Industrial Programmable Power Supply

Test Equipment Bias Generator

Use Scenario: Benchtop DC supply with front-panel voltage control via potentiometer.

IC Role / Device Role / Timing Role: Adjustable linear regulator core; sets precise output via R1/R2 divider with manual or DAC-driven R2.

Use Value: Delivers <500 mA at 1.2–30 V with <5 mV load regulation and 0.003% noise-enabling clean bias for op-amps and ADC references.

Use Scenario: Calibration-grade voltage source in automated test systems.

IC Role / Device Role / Timing Role: Precision reference generator using fixed R1 and digitally switched R2 array.

Use Value: 1.25 V reference tolerance ±1% and 0.7% temperature stability ensure <0.1% total output drift over 0–70°C operating range.

LED Constant-Current Driver

Remote-Sensing Distributed Power Node

Use Scenario: Low-cost constant-current driver for high-brightness LED strings.

IC Role / Device Role / Timing Role: Configured as current regulator with R1 between ADJ and OUT; I_O = 1.25 V / R1.

Use Value: Maintains ±3% current accuracy over input voltage variation (VI–VO = 3–40 V) and temperature due to stable V_REF and low I_ADJ drift.

Use Scenario: Local regulation at point-of-load in multi-board embedded system with long PCB traces.

IC Role / Device Role / Timing Role: Remote ground sensing via separate R2 ground trace to load return point.

Use Value: Compensates for up to 200 mV IR drop in power distribution path, maintaining ±10 mV output accuracy at load terminals.

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable linear regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM317DT	Same architecture but rated for 0–125°C T_J (vs. LM217MT's –40–125°C); slightly looser load regulation (25 mV vs. 15 mV typ)	Suitable for commercial-temperature environments only; not qualified for extended industrial ambient	Select when cost sensitivity outweighs extended temp requirement and tighter regulation is noncritical
TLV1117-ADJ	Lower dropout (1.2 V), lower max current (800 mA), higher PSRR (75 dB), but narrower V_O range (1.25–15 V)	Not viable for >15 V outputs; better for low-VIN, low-noise LDO use cases where headroom is constrained	Choose only for sub-15 V applications needing ultra-low noise and minimal VI–VO overhead

Compared with LM317DT, LM217MT offers wider temperature qualification and tighter load regulation; versus TLV1117-ADJ, it trades dropout and PSRR for full 37 V output capability and robust high-voltage floating operation-making it uniquely suited for industrial programmable supplies and high-side bias generation.

Availability

LM217MT is available at Aetrix Electronics and suitable for industrial programmable power supplies, test equipment bias generators, LED constant-current drivers, and remote-sensing distributed power nodes requiring stable component supply with guaranteed long-term continuity.

Supply support for LM217MT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power ICs, analog chips, and MEMS sensors for industrial, automotive, and consumer markets.

The LM217M series belongs to ST's legacy linear regulator product line, engineered specifically for rugged, wide-input-range adjustable DC-DC conversion in industrial control, instrumentation, and power management systems.

FAQ

What is the minimum load current required for stable regulation with LM217MT?

The LM217MT requires a minimum load current of 3.5 mA (typical) to 5 mA (max) to maintain regulation, especially when VI–VO approaches 40 V. This is due to its design where all quiescent current returns to the output terminal. If load current falls below this threshold, output voltage may rise uncontrollably. A bleeder resistor from OUT to GND ensures compliance.

Can LM217MT be used in floating (high-side) configurations?

Yes-LM217MT is explicitly designed for floating operation. It regulates based only on the differential voltage between IN and OUT pins (VI–VO ≤ 40 V), not absolute ground potential. This allows use as a high-side regulator, battery charger controller, or negative-output configuration (with inverted reference), provided thermal limits and safe-area constraints are observed.

How does the adjustment pin current affect output accuracy?

I_ADJ (50–100 µA, max 5 µA variation) flows through R2 in the feedback divider, adding an error term of I_ADJ × R2 to the output equation. For example, with R2 = 10 kΩ, error is ≤0.5 V. To minimize impact, keep R2 ≤ 2.4 kΩ for 1% accuracy at 10 V output-or use a low-impedance buffer if high-R dividers are mandatory.

What thermal considerations apply when using LM217MT in DPAK package?

In DPAK, LM217MT has R_thJA = 100 °C/W (no copper pour) and R_thJC = 8 °C/W. With 10 W dissipation, junction temperature rises 1000°C above ambient-so practical use demands PCB copper area (≥4 cm²) or heatsinking. Derate output current above 50°C ambient; thermal shutdown activates at 125°C junction, with automatic recovery after cooldown.

LM217MT Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Adjustable

Number of Regulators:: 1

Voltage - Input (Max):: 40V

Voltage - Output (Min/Fixed):: 1.2V

Voltage - Output (Max):: 37V

Voltage Dropout (Max):: -

Current - Output:: 500mA

Current - Quiescent (Iq):: -

Current - Supply (Max):: -

PSRR:: 80dB ~ 65dB (120Hz)

Control Features:: -

Protection Features:: Over Temperature, Short Circuit

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

LM217MT FAQ

1.How can I place an order for LM217MT through Aetrix?

Please submit a Request for Quotation (RFQ) for LM217MT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LM217MT reliable?

The price and inventory of LM217MT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM217MT is usually 5 days.

3.What payment methods are accepted for LM217MT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM217MT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM217MT?

LM217MT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM217MT order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LM217MT?

For technical support, including LM217MT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM217MT requirements.

6.How does Aetrix verify that LM217MT is sourced from the original manufacturer or authorized distributors?

All LM217MT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM217MT meets industry standards.

7.What is the process for return or replacement of LM217MT?

All LM217MT units undergo pre-shipment inspection (PSI). If there is an issue with LM217MT, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LM217MT part is unused and in its original packaging.

Return procedure for LM217MT:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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