NCV4266-2CST50T3G — 5V/150mA Automotive LDO with Enable (SOT-223)

What Are the Technical Specifications of NCV4266-2CST50T3G?

Key numbers that matter. Per the onsemi NCV4266 datasheet (Rev 23, NCV4266/D), the SOT-223-4 package delivers R_θJA of 96°C/W on a 168mm² copper pad, dropping to 77°C/W with 736mm². That 19°C/W gap is the difference between "works on the bench" and "works in a parked car in Phoenix."

At 150mA with a 12V input, the part dissipates about 1.05W (7V drop × 150mA). On the minimal pad, that's a 101°C rise — pushing past 125°C at 25°C ambient. Give it copper, or give it less voltage drop.

When Should You Use (and NOT Use) the NCV4266?

What Are the Alternatives to NCV4266-2CST50T3G?

NCV4266 vs TLE4266-2G — the sourcing decision. These two are functionally equivalent: both 5V/150mA, both automotive, both SOT-223-4 with enable. The TLE4266 shaves 20µA off the quiescent current. In practice, the choice comes down to availability, pricing, and whether your PPAP package already approves one of them.

If you're designing a new ECU, qualify both in the BOM. Single-sourcing an automotive LDO with one manufacturer is a production-line stoppage waiting to happen.

What Are the Typical Applications of NCV4266?

Body Control Module (BCM) standby rail. The NCV4266 powers the always-on 5V domain in a BCM — the MCU wake-up comparator, LIN transceiver, and CAN monitor mode. At 60µA quiescent, a 45Ah car battery takes over 85 years to drain from this LDO alone. The real drain comes from whatever's downstream.

Sensor supply in distributed ECUs. Engine-bay sensor nodes need a clean 5V rail that starts at -40°C and survives proximity to a turbocharger. The NCV4266's ±2% accuracy across the full temperature range means a ratiometric sensor bridge won't drift between a Minnesota winter and a Death Valley summer.

Infotainment head-unit auxiliary rail. The main processor runs from a multi-amp buck. But CAN, Bluetooth, and steering-wheel buttons need a 5V rail that stays alive during cranking. At 12V in, 150mA load, the NCV4266 dissipates just over 1W. Spread across a 4-layer board's copper fill, that's well within thermal budget.

Electric power steering (EPS) torque sensor interface. Torque sensors output a differential signal on a precision 5V reference. Any droop gets amplified as steering-angle error. The NCV4266's ±2% accuracy and 68dB PSRR keep it clean, even as the EPS motor pulls 80A pulses from the same 12V bus.

Why Buy NCV4266 from ICMASS?

Automotive traceability that matters. We ship NCV4266 lots with date-code traceability back to the onsemi factory. If a batch gets flagged in your end-of-line test, we can trace it to the reel within 24 hours. For PPAP production parts, that's the difference between a containment note and a line shutdown.

Cross-reference support for automotive LDOs. Your BOM says TLE4266 but lead times are 26 weeks? NCV4264 but the pinout doesn't match your layout? We'll go through the pinout, dropout, quiescent current, and protection specs with you and recommend what actually works — as a drop-in or with the minimum layout change.

Single-source automotive power management BOM. You're stocking NCV4266 LDOs alongside NCV4271 voltage trackers, NCV8402 low-side drivers, and NCV7340 CAN transceivers. We carry the onsemi automotive power portfolio in one shipment from our Shenzhen warehouse. No chasing five distributors for five line items.

Shenzhen warehouse, global DHL/FedEx. Same-day shipping for orders placed before 15:00 CST. International delivery in 5–10 days. Contact us for a quote on your specific quantity.

Frequently Asked Questions About NCV4266-2CST50T3G

Q1: Can NCV4266 replace a TLE4266 directly?

A: Yes — the pinout, package, and output spec match. Both are SOT-223-4 with the same IN/GND/OUT/EN pin assignment. The NCV4266 has slightly lower dropout (230mV vs 250mV typ) and similar quiescent current. But check your enable logic threshold. The NCV4266's EN high threshold is 2.0V min, while the TLE4266 turns on at 3.5V. If your MCU GPIO swings to 3.3V, verify it meets the threshold of whichever part you select.

Q2: How much copper area does the NCV4266 need on the PCB?

A: 168mm² minimum for RθJA of 96°C/W; 736mm² drops it to 77°C/W. Start with at least 300mm². The SOT-223's exposed tab is the primary heat path. Solder it to a solid copper plane, not a thermal-relief pad with spoke connections.

At 150mA with a 7V drop (12V in, 5V out), you're dissipating 1.05W. With 300mm² of 1oz copper, the junction runs roughly 89°C above ambient. Fine at 25°C. Marginal at 60°C under the hood. For hot environments, reduce the voltage drop or add inner-layer copper through thermal vias.

Q3: What output capacitor does NCV4266 need for stability?

A: 22µF ceramic on the output, plus 1µF and 100nF on the input. Per the onsemi datasheet (Rev 23), the NCV4266 is stable with typical output capacitances and ESR values. A 22µF X7R ceramic with a 10V or 16V rating is the standard choice. Add a 1Ω series resistor with the 100nF input cap to damp LC ringing from wiring harness inductance. On an automotive ECU, the input wire might be 3 metres of unshielded cable.

Q4: Why does NCV4266 cost more than a standard 7805?

A: You're paying for the automotive qualification, not the silicon area. A 7805 and an NCV4266 both output 5V, but the NCV4266 is tested to operate at 150°C junction, qualified to AEC-Q100, characterized for -42V reverse battery, and comes with PPAP documentation. A 7805 has none of that. For a bench power supply, the 7805 is fine. For an ECU that ships 100,000 units a year and can't afford a single warranty return, the NCV4266's qualification package is cheap insurance.

Q5: Can I parallel two NCV4266s for 300mA?

A: Don't. LDOs don't share current evenly without ballast resistors, and the NCV4266 isn't designed for parallel operation. If you need 300mA, use a single higher-current automotive LDO like the NCV47711 (350mA) or an NCV4269 (150mA with external pass transistor). Ballasting two LDOs adds PCB area, loses voltage accuracy, and creates a failure mode where one LDO takes all the current anyway if the other one's output drifts 20mV higher.

Q6: What happens when the EN pin is left floating?

A: The regulator may be off, or may oscillate between on and off — don't do it. The EN pin has an internal pull-down in most operating conditions, but the datasheet specifies it should be driven, not left floating. Tie it to IN through a 100kΩ resistor for always-on operation, or drive it from a GPIO with a clean high/low signal. A floating pin in an automotive environment picks up noise from ignition coils and injector drivers.

Q7: NCV4266-2CST50T3G vs NCV4266ST50T3G — what does the "-2C" mean?

A: The "-2C" variant has improved startup behaviour during input voltage transients and a slightly wider enable threshold range. Both are 5V/150mA automotive LDOs in SOT-223. The -2C revision adds specific improvements for cold-crank scenarios where the battery voltage dips to 3-4V during starter engagement and then snaps back to 14V. If your ECU needs to stay alive through cranking, use the -2C. Otherwise, the base NCV4266 works the same in steady-state operation.

Q8: Can I use NCV4266 in a non-automotive design?

A: Yes — it works perfectly, but you're paying a premium for qualifications you may not need. The NCV4266 regulates 5V just as well in an industrial controller or a medical device as it does in a car. The wide 5.5–45V input and reverse-battery protection are genuinely useful in any 12V/24V system. But if your product doesn't need AEC-Q100 and PPAP, the NCP1117ST50T3G (commercial grade, same manufacturer, same package) delivers the same output at roughly 30–50% lower cost.

Related Products

• NCV4264-2CST33T3G — 3.3V/100mA Automotive LDO, same family, SOT-223-3
• NCP1117ST33T3G — 3.3V/1A Commercial LDO, SOT-223, cost-reduced alternative for non-auto
• LM317LDR2G — Adjustable LDO 100mA, SOP-8, for prototyping and adjustable rails
• NCV4266 vs TLE4266 vs NCV4264 — Automotive LDO Selection Guide