onsemi NCV4254CDSTR2G

Overview

NCV4254CDSTR2G from onsemi is an automotive-grade low-dropout tracking voltage regulator in SOIC-8 package, delivering up to 70 mA output current with ±3 mV tracking accuracy (typ. 220 mV dropout at 70 mA), AEC-Q100 Grade 1 qualified, and featuring reverse input voltage protection and thermal shutdown. It serves as a buffered, adjustable output stage for remote sensor power supplies in vehicle ECUs.

For engineers reviewing the NCV4254CDSTR2G datasheet, pinout, applications, or equivalent options, key selection criteria include its status-output fault signaling, wide 4–45 V input range, ±10 mV tracking error over temperature, and suitability for isolated off-module loads requiring automotive reliability.

Technical Context

The NCV4254CDSTR2G implements a PNP-based tracking architecture where VOUT precisely follows the voltage applied to the EN/REF pin, with internal op-amp control loop stability dependent on external output capacitance (≥2.2 µF, ESR < 5 Ω). Its ST pin provides open-collector status indication with undervoltage/overvoltage thresholds referenced to VEN/REF (±77 mV typical).

It integrates comprehensive protection: current limiting (71–150 mA), thermal shutdown (151–200 °C), reverse input voltage tolerance (−20 V), and reverse bias protection. Standby disable current is ≤5 µA when EN/REF < 0.4 V, enabling low-power system wake-up control.

Key Specifications

Pinout & Package

NCV4254CDSTR2G uses the SOIC-8 (Case 751, Suffix D) surface-mount package with exposed pad not present (SOIC-8 NB, not EP). Pin 1 is VIN; pins 2,3,6,7 are GND; pin 4 is ST (open-collector status output); pin 5 is EN/REF (enable/reference input); pin 8 is VIN (dual VIN connection for current sharing and noise reduction).

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCV4254CDSTR2G, NCV4274CDTR2G offers greater current capacity but removes diagnostic capability, while TLV73350PDBVR trades automotive reliability and protection for raw performance in benign environments - making NCV4254CDSTR2G the optimal choice for safety-aware, fault-reporting automotive subsystems.

Availability

NCV4254CDSTR2G is available at Aetrix Electronics and suitable for automotive sensor power supplies, body control modules, engine control units, and ADAS camera bias circuits requiring stable component supply across extended temperature and voltage ranges.

Supply support for NCV4254CDSTR2G 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The NCV4254C product line delivers automotive-qualified tracking regulators designed specifically for off-module sensor power and fault-aware sub-regulation in harsh-temperature, high-reliability vehicle electronics.

FAQ

What is the function of the ST pin on the NCV4254CDSTR2G?

The ST pin on the NCV4254CDSTR2G is an open-collector status output that pulls low when the regulated output voltage deviates beyond ±77 mV of the EN/REF reference voltage (indicating undervoltage or overvoltage) or during thermal shutdown or current-limit fault. It requires an external pull-up resistor (typically 10 kΩ) to VREF or VOUT and sinks up to 1 mA. This enables real-time fault reporting to a microcontroller without additional monitoring circuitry - a core feature distinguishing the ST version of the NCV4254CDSTR2G from the ADJ variant.

Does the NCV4254CDSTR2G require an external output capacitor, and what are the requirements?

Yes, the NCV4254CDSTR2G requires an external output capacitor for loop stability - operation without it causes oscillation. The datasheet specifies a minimum 2.2 µF ceramic or tantalum capacitor with ESR < 5 Ω, placed directly at the VOUT pin. At −40 °C, the capacitor must retain rated capacitance and low ESR to ensure stability across the full temperature range. Larger values improve transient response and maintain output during brief negative input transients, but do not affect regulation accuracy - a key design requirement confirmed in the NCV4254CDSTR2G application information section.

How does the NCV4254CDSTR2G handle reverse input voltage conditions?

The NCV4254CDSTR2G is rated for −20 V on VIN with VOUT = 0 V and VEN/REF = 5 V, drawing only −0.2 to −1 mA reverse input current. This reverse voltage protection prevents damage during battery reverse connection or jump-start events. However, the thermal shutdown circuit remains inactive during reverse polarity, so sustained reverse bias must still be limited in duration. This behavior is explicitly characterized in Table 7 (Electrical Characteristics) and confirmed in the Application Information section - a critical differentiator for automotive field reliability not found in standard industrial LDOs.

What is the maximum junction temperature and thermal derating behavior of the NCV4254CDSTR2G?

The NCV4254CDSTR2G has a maximum junction temperature of 150 °C per Recommended Operating Ranges (Table 6), with thermal shutdown activating between 151 °C and 200 °C. Its SOIC-8 package exhibits RJA = 115 °C/W on 1 oz copper (645 mm²), allowing ~1.3 W max dissipation at 25 °C ambient. Derating is linear: at 85 °C ambient, max power drops to ~0.75 W. This thermal profile is validated in Figures 19–20 and Equation 1 of the datasheet - essential for sizing heatsinking in engine bay applications where the NCV4254CDSTR2G operates continuously near its limits.

Can the NCV4254CDSTR2G be used as a high-side driver, and how is it configured?

Yes, the NCV4254CDSTR2G can be configured as a high-side driver by grounding the ADJ pin - but this applies only to the ADJ version (e.g., NCV4254CDAJR2G). The NCV4254CDSTR2G is the Status-output version and does not have an ADJ pin; its pin 4 is ST, not ADJ. Therefore, the NCV4254CDSTR2G cannot be used as a high-side driver. Figure 28 in the datasheet explicitly shows this configuration for the ADJ variant only, and Table 1 confirms pin 4 function as ST for the DSTR2G part - a critical distinction verified across ordering information and pin descriptions.