Texas Instruments LM2678SX-3.3/NOPB

Mfr. Part

LM2678SX-3.3/NOPB

Manufacturer

Luminary Micro Texas Instruments. Y-IC is a quality distributor of TI brand products and we will provide you with the best products and services

Detailed Description

5 A non-synchronous step-down (buck) DC-DC regulator, fixed 3.3 V output, part of TI SIMPLE SWITCHER series. Wide input range 8 V to 40 V, 260 kHz fixed switching frequency, requires an external inductor and Schottky diode. Surface-mount power package TO-263-7 for high thermal performance. RoHS3 lead-free NOPB variant

Key Features

Input voltage range 8 V to 40 V supports 12 V and 24 V rails and transient-prone supplies

Fixed 3.3 V output simplifies design and reduces BOM risk

5 A continuous output current with integrated high-side switch

260 kHz fixed switching frequency for smaller magnetics and capacitors

Non-synchronous topology uses an external Schottky rectifier for efficiency and low losses

Enable ON OFF control for power sequencing and low-power standby

Internal current limit and thermal shutdown for robust fault protection

SIMPLE SWITCHER family with well-documented design guidance and predictable stability

RoHS3 compliant lead-free NOPB finish

Key Advantages

Reliable 5 A output with wide VIN tolerance makes it a strong drop-in for industrial and automotive-like environments

Simple stable power stage with a handful of external parts speeds time to market

Fixed 3.3 V version removes feedback resistor selection errors

Mature SIMPLE SWITCHER ecosystem and app notes reduce design risk

TO-263 power package and exposed tab enable effective heat dissipation on standard PCBs

Packaging

Type Tape and Reel TR for automated SMT

Device package TO-263-7 also called DDPAK 7 leads plus thermal tab

Material Molded epoxy body over copper leadframe with matte tin lead finish Pb free NOPB

Size body approx 10.1 mm x 9.3 mm x 4.5 mm reference for TO-263 family actual outline see datasheet

Pin configuration 7 pins plus exposed tab typical functions include VIN SW switch node GND PGND FB feedback ON OFF enable BOOST bootstrap Refer to datasheet pin map for exact numbering

Lead pitch approx 1.27 mm for TO-263

Mounting Surface mount reflow capable

Thermal characteristics typical RθJC around a few C W and RθJA strongly layout dependent often 30 to 50 C W with generous copper areas Exposed tab used as primary heat path

Electrical properties related to package high current capability on SW and tab low lead inductance suitable for 260 kHz operation

Moisture sensitivity typically MSL 1 check label datasheet for exact rating

Operating junction temperature 40 C to 125 C TJ per device rating

Lifecycle

Status Active based on current industry information not nearing discontinuation

Direct family variants

- LM2678SX-5.0 NOPB fixed 5.0 V 5 A same package and family

- LM2678SX-ADJ NOPB adjustable output 1.2 V to 37 V typical same package and family

- LM2678T-3.3 NOPB TO-220 through hole version fixed 3.3 V 5 A

Higher frequency or similar TI alternatives evaluate fit to your design

- LM2679SX-3.3 NOPB 5 A SIMPLE SWITCHER higher switching frequency family member

- LM22678 TJ ADJ 5 A 42 V SIMPLE SWITCHER adjustable can be set to 3.3 V

- TPS54560B adjustable up to 5 A and up to 60 V VIN can be set to 3.3 V improved efficiency options

- LM2596 and LM2576 families lower current or lower frequency alternatives if 5 A not required

If you need a footprint-compatible substitute or a form fit function cross contact our Y-IC sales team on our website for the latest vetted options

Key Application Areas

Industrial control PLCs HMIs sensors from 24 V rails to 3.3 V logic and MCU power

Automotive infotainment and body electronics 12 V systems with transient headroom note VIN max 40 V

Factory automation motor drives relay drivers I O modules

Test and measurement instruments local 3.3 V digital rails

Networking and telecom edge equipment with 12 V intermediate bus

General purpose 3.3 V rails in embedded systems and single board computers

Datasheet

Our website hosts the most authoritative and up to date datasheet for LM2678SX-3.3 NOPB We recommend downloading it directly on this page to get exact pinout thermal data layout guidance and tested application circuits

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