LM350T

Texas Instruments

LM350T, 3A adjustable positive voltage regulator, 1.25V to 33V output, 35V max input, PSRR 86dB~65dB at 120Hz, TO-220-3, through hole, 0°C~125°C.

Texas Instruments LM350T
Download datasheet (PDF)
[IN STOCK] In Stock: 24 pcs
$0.75/ pc

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MOQ 1 · Tube · RoHS · EIA-481 · DAP/DDP · T/T

Technical specifications

LM350T specifications
Parameter / AttributeSpecification / Value
Output typeAdjustable
MountingThrough Hole
Voltage - input35V
Voltage - output33V
Voltage - output (Min (Fixed))1.25V
Output current3A
Operating temperature0°C~125°C
PSRR86dB ~ 65dB (120Hz)
PackageTube
CaseTO-220-3
Protection featuresOver Current, Over Temperature, Short Circuit
Number of regulators1
Output configurationPositive
100% Footprint Match · Solder-Ready (No PCB Redesign Needed)

Need Stock or a Drop-in Second-Source for LM350T?

Package: TO-220 / SOT-223 / TO-92 / DPAK · Pin-compatible replacements with immediate Shenzhen spot stock

Footprint Match 99%
Supply Chain & Allocation Reality:

The LM317 has been the default adjustable linear regulator since the 1970s and remains in continuous production across TI, ST, onsemi and a long clone list. The confusion is all in the suffix: LM317, LM317T, LM317L and LM317M are the same regulator design at different packages and current limits, and the modern surface-mount sockets are usually filled by SOT-223 clones such as the AMS317. Where a rail needs more than the 1.5A a TO-220 LM317 can pass, the family ladder (LM350 at 3A, LM338 at 5A) is the correct answer - with a lower output-voltage ceiling as the trade.

Verified Pin-Compatible Replacements (4 verified alternatives)

LM317T STMicroelectronics / TI / onsemi TO-220
100% Drop-in (Zero Code Change)
Availability & Target Pricing:

The Full-Current Package, Named

Shenzhen Spot Stock (24-48h Dispatch)

Electrical & Core Specs:

The TO-220 member of the family: 1.5A output at the full 1.2V to 37V adjustment range, reference 1.25V, adjustment pin current about 50uA.

Input up to 40V class (see the vendor datasheet for the exact maximum differential); output 1.25V to 37V set by the two-resistor divider.

Compatibility & Drop-In Notes: Electrically identical to any other LM317 suffix; the T suffix simply names the TO-220 body that the original 1.5A headline rating refers to.
Package & Solder Footprint: TO-220, standard pin order ADJ / OUT / IN (confirm orientation from the front view; the pin row is not symmetric).
Shenzhen Warehouse Stock & MOQ: Deep multi-fab stock; the part every bench expects.
LM317L TI / onsemi TO-92
Functional Equivalent
Availability & Target Pricing:

Small Current, Small Body

Shenzhen Spot Stock (24-48h Dispatch)

Electrical & Core Specs:

The 100mA member: same 1.25V reference and adjustment behavior, but rated at a tenth of the TO-220 current.

Same 1.25V to 37V output range; input differential and dissipation limited by the tiny TO-92 body.

Compatibility & Drop-In Notes: Any direct swap between suffixes must respect the current rating: fitting an L part where a T failed thermally repeats the failure in miniature.
Package & Solder Footprint: TO-92 lead order differs from the TO-220 row - read the datasheet drawing rather than assuming.
Shenzhen Warehouse Stock & MOQ: Stocked as the repair-size part for instrument bias supplies.
AMS317 Advanced Monolithic Systems / multiple Chinese fabs SOT-223
Functional Equivalent
Availability & Target Pricing:

The SMD Socket Filler

Shenzhen Spot Stock (24-48h Dispatch)

Electrical & Core Specs:

The LM317-compatible adjustable regulator in SOT-223: same 1.25V reference and divider-based setting; current rating is package-limited (roughly 1A only with generous copper).

Same adjustment range; thermal behavior is the whole story - junction-to-ambient around 60 degC/W without a copper pour.

Compatibility & Drop-In Notes: Electrically a valid stand-in for small loads. Where the original was a TO-220 passing close to 1A continuously, the SOT-223 swap needs a thermal review, not a pin review - the footprint forces the conversation.
Package & Solder Footprint: SOT-223 with the tab as the output; the land pattern is the standard SOT-223 used across the clone family.
Shenzhen Warehouse Stock & MOQ: Massive Chinese-fab stock; the volume part of the adjustable-regulator market.
LM338 STMicroelectronics / TI TO-220 / TO-3
Functional Equivalent
Availability & Target Pricing:

The Current Ladder Top (5A)

Shenzhen Spot Stock (24-48h Dispatch)

Electrical & Core Specs:

The 5A member of the adjustable family: same adjustment topology, higher current die - and a lower output ceiling (around 32V rather than 37V).

Output to about 32V; input differential limits per the datasheet; LM350 (3A) sits between this and the LM317.

Compatibility & Drop-In Notes: Check the reduced maximum output voltage if the design ran an LM317 near 37V. Current capability is real only with the matching heatsink and input headroom.
Package & Solder Footprint: TO-220 pin order matches the LM317T row; TO-3 cans exist for the oldest fixtures.
Shenzhen Warehouse Stock & MOQ: Active production; stocked in the same drawer family as the LM317.
Buyer & Quality Checklist for Sourcing Alternatives
  • Decode the suffix before ordering: T = TO-220 (1.5A), L = TO-92 (100mA), M = mid-power TO-202 class (500mA), K = TO-3, D/S = DPAK/D2PAK, N or MP = SOT-223. Same regulator, different thermal envelopes.
  • The LM317 output cannot go below its 1.25V reference without a negative rail below ground - designs wanting a true 0V-output supply need a different regulator, not a different LM317.
  • SOT-223 clones (AMS317 and the Chinese fab family) are electrically compatible but package-limited: derate to roughly 1A and give the tab real copper or the part runs at its thermal wall.
  • For currents above 1.5A go up the ladder (LM350 3A, LM338 5A) and re-check the reduced maximum output voltage; two parallel LM317s are not a substitute.
  • The negative-rail complement for split supplies is the LM337, with mirrored pin order - never fit a positive part in the negative socket.
  • The adjustment-pin current is small but not zero (about 50uA): for precision outputs use the datasheet-recommended resistor network and keep the adjustment pin bypassed.
Frequently Asked Technical Questions

Q: What is the difference between LM317 and LM317T?

A: Package only: LM317T is the TO-220 body, which is the form the 1.5A rating refers to. Electrically the die family is identical across suffixes - the differences to watch are current rating and thermal resistance of each package.

Q: Can an AMS317 (SOT-223) replace a TO-220 LM317?

A: Electrically yes, thermally not blindly: the SOT-223 part is package-limited to roughly 1A with good copper and far less without it. On loads that heated the TO-220, the SOT-223 swap needs a dissipation review first.

Q: How do I get more than 1.5A from an LM317 circuit?

A: Step up the family: LM350 for 3A, LM338 for 5A (both with a slightly lower output ceiling), each with the heatsinking the current demands. Paralleling LM317s does not work because the parts do not share current.

Technical details

3A adjustable regulator — the LM317 upgrade for higher current

The LM350T is a 3A adjustable positive voltage regulator in a TO-220-3 through-hole package. It delivers the same 1.25V reference and adjustable output architecture as the LM317, but doubles the output current ceiling to 3A — the key spec that decides the design-in for any linear supply that needs more than 1.5A without moving to a separate pass transistor. Output adjusts from 1.25V up to 33V from a 35V maximum input rail. The 86dB to 65dB PSRR at 120Hz (mains frequency) tells you this part was designed for post-rectifier ripple rejection in linear power supplies — the 86dB floor at light load, dropping to 65dB under full 3A draw, is the ripple-rejection envelope a designer budgets for.

Built-in protection saves external supervision

Over-current, over-temperature, and short-circuit protection are integrated — no external crowbar or thermal watchdog needed. For a 3A part in a TO-220, the thermal limit is the practical boundary: at 3A with a 10V drop, you're dissipating 30W, which demands a heatsink sized for the junction-to-ambient thermal path. The protection circuits prevent die damage during transient faults or start-up into a shorted output.

Obsolete — sourcing through the independent channel

For a production BOM that still calls out this regulator, the window for last-time-buy lots has closed; current availability depends on broker inventory that has already been through the channel.

TO-220 mounting and thermal design

The TO-220-3 package requires a heatsink for any load above about 1A at moderate dropout. The tab is the output pin (Vout), so the heatsink interface is at output potential — insulating pad and washer are needed if the heatsink is chassis-grounded. The through-hole leads suit point-to-point wiring or PCB mounting with 0.100-inch pitch hole spacing.

LM350T
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