onsemi CS8271YD8

Overview

CS8271YD8 from onsemi is an adjustable micropower linear voltage regulator in SO-8 package, delivering 100 mA output current with 600 mV max dropout at full load and 60 µA typical quiescent current in active mode. It features logic-compatible ENABLE pin for shutdown (50 µA IQ sleep), internal protection against +60 V load dump, –15 V reverse battery, short circuit, overvoltage (>30 V shutdown), and thermal shutdown (180°C typ). It is designed for battery-powered and automotive systems requiring stable low-power regulation.

For engineers reviewing the CS8271YD8 datasheet, pinout, applications, or equivalent options, key selection criteria include adjustable 5.0–12 V output, 100 mA capability with <600 mV dropout, ENABLE-controlled sleep mode, automotive-grade transient tolerance (+60 V), and SO-8 pin compatibility with LM2931.

Technical Context

The CS8271YD8 integrates a bandgap reference, error amplifier, current-limited pass transistor, and fault-protection circuitry including overvoltage shutdown triggered above 30 V and thermal shutdown at ~180°C. Its feedback loop uses an external resistor divider on the Adj pin to set output voltage, with reference voltage tightly specified at 1.246–1.297 V and adj pin bias current ≤500 nA.

Control logic centers on the ENABLE pin: a logic-high input (>2.0 V typ) disables the pass transistor, placing the device in high-impedance sleep mode with only 20–75 µA quiescent draw. Protection functions operate autonomously-no external components required for +60 V load dump survival, –15 V reverse battery tolerance, or short-circuit current limiting (105–300 mA).

Key Specifications

Pinout & Package

CS8271YD8 is housed in an SO-8 (D suffix, Case 751) surface-mount package with standard 1.27 mm pitch and exposed pad not present. Pin 1 is marked by notch or dot; orientation matches JEDEC MS-012.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2931Z-5.0/NOPB and TLV73312PDBVR, the CS8271YD8 uniquely combines adjustable output, ENABLE control, +60 V load dump tolerance, and reverse-battery resilience in one SO-8 package-making it the only choice for programmable, automotive-qualified micropower LDOs.

Availability

CS8271YD8 is available at Aetrix Electronics and suitable for automotive body electronics, industrial battery-powered sensors, and medical portable devices requiring stable component supply with guaranteed long-term availability and automotive-grade reliability.

Supply support for CS8271YD8 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 focused on energy-efficient innovation, serving automotive, industrial, cloud, and IoT markets with silicon-based solutions.

The CS8271YD8 belongs to onsemi's Smart Regulator® family of protected linear regulators, engineered specifically for harsh-environment applications demanding integrated fault protection, micropower operation, and automotive qualification.

FAQ

What is the minimum input voltage required for the CS8271YD8 to regulate a 12 V output?

The CS8271YD8 requires VIN ≥ VOUT + dropout voltage. At 100 mA load, max dropout is 600 mV, so minimum VIN = 12.6 V. At light loads (100 µA), dropout drops to 100 mV, allowing regulation down to 12.1 V. Input must remain ≥ VOUT + 1.0 V per datasheet test conditions to ensure stability and specification compliance for the CS8271YD8.

Can the CS8271YD8 be used without the ENABLE function connected?

Yes-the ENABLE pin can be left unconnected or tied to GND for permanent enable. When floating, internal leakage keeps the pin near GND, ensuring normal operation. However, tying ENABLE directly to VIN is unsafe: absolute max rating is 10 V on ENABLE, and VIN may exceed that. For guaranteed enable, connect ENABLE to GND via ≤10 kΩ resistor; for guaranteed disable, pull up to ≤2.6 V logic source. This behavior is explicitly defined in the CS8271YD8 datasheet.

What output capacitor is required for stable operation of the CS8271YD8?

The CS8271YD8 requires a minimum 10 µF output capacitor with ≥0.5 Ω ESR for loop stability-tantalum or aluminum electrolytic types are recommended. Ceramic capacitors alone cause oscillation due to near-zero ESR. The datasheet specifies COUT = 10 µF in Figure 4 and warns against film/ceramic caps without added series resistance. Using undersized or low-ESR capacitors risks instability, especially at temperature extremes, which directly impacts reliability of the CS8271YD8 in production systems.

Does the CS8271YD8 require an input bypass capacitor?

Yes-a 0.1 µF ceramic capacitor is required between VIN and GND, placed as close as possible to the CS8271YD8 pins. This capacitor filters high-frequency noise and provides local charge storage during transient load steps. The datasheet states it is "required if regulator is away from power supply filter" (Figure 6 note), and omission risks instability or degraded line regulation. This 0.1 µF input cap is mandatory for robust performance of the CS8271YD8 across its full operating range.

How does the CS8271YD8 handle reverse battery connection?

When –15 V is applied to VIN with VOUT biased (e.g., by load), the CS8271YD8 limits reverse current to ≤200 µA and sustains no damage. This is achieved via internal blocking structure-not an external diode. The device remains functional after reverse polarity removal. This feature is tested and guaranteed per Absolute Maximum Ratings table, making the CS8271YD8 suitable for automotive service environments where battery terminals may be accidentally reversed during maintenance.