onsemi CS8371ET7

Overview

CS8371ET7 from onsemi is an automotive-grade dual-output linear regulator providing independent 8.0 V ±5% / 1.0 A and 5.0 V ±5% / 250 mA outputs, each controlled by dedicated ENABLE pins, with NOCAP technology enabling stable operation without external output capacitors - used in automotive radio systems to power displays/tape motors (8 V) and tuner ICs/memory (5 V).

For engineers reviewing the CS8371ET7 datasheet, pinout, applications, or equivalent options, key selection considerations include independent enable control per output, 45 V load dump transient tolerance, NOCAP stability for 8 V output, thermal shutdown at 150 °C, and TO-220-7 package with copper tab for heatsinking.

Technical Context

The CS8371ET7 integrates two independent linear regulator channels: a high-current 8.0 V channel with sense feedback and a lower-current 5.0 V channel with Darlington NPN output structure. Each channel features CMOS-compatible ENABLE inputs and separate fault protection circuits.

Its NOCAP architecture eliminates the need for external compensation capacitors on the 8.0 V output by embedding high-gain (>80 dB), wide-bandwidth (>100 kHz) internal compensation, while the 5.0 V output remains inherently stable with any capacitive load or no capacitor. Protection includes overvoltage shutdown (24–30 V), thermal shutdown (150 °C), short-circuit current limiting (1.1–2.5 A for VOUT1; 270–600 mA for VOUT2), and 45 V peak transient tolerance.

Key Specifications

Pinout & Package

The CS8371ET7 is housed in a 7-lead TO-220 package (Case 821E) with copper tab electrically connected to GND, enabling direct heatsink mounting for thermal management in high-dissipation applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output linear regulator applications.

Compared with LM2678T-8.0/NOPB and TPS7H1101AQPWPRQ1, the CS8371ET7 uniquely integrates two independently enabled, NOCAP-stabilized outputs in one TO-220 package - reducing bill-of-materials, simplifying layout, and eliminating external capacitors for the 8 V rail while meeting stringent automotive transient and thermal requirements.

Availability

CS8371ET7 is available at Aetrix Electronics and suitable for automotive radio power supply, infotainment head unit design, and telematics control module development requiring stable component supply, long-term lifecycle support, and AEC-compliant sourcing.

Supply support for CS8371ET7 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 manufacturer specializing in energy-efficient silicon solutions for automotive, industrial, cloud, and IoT applications.

The CS8371ET7 belongs to onsemi's SMART REGULATOR® family of automotive-qualified linear regulators, designed specifically for robust, low-noise dual-rail power delivery in harsh vehicle environments where reliability, transient immunity, and thermal resilience are critical.

FAQ

What is the maximum input voltage the CS8371ET7 can withstand during load dump events?

The CS8371ET7 is rated for +45 V peak transient voltage under load dump conditions (per ISO 7637-2 Pulse 5a), making it suitable for direct connection to automotive 12 V battery systems without additional TVS protection in most implementations. This rating applies when VCC is supplied at nominal 14 V, and the device remains functional and undamaged within its specified junction temperature limits during such events. The CS8371ET7 achieves this via internal clamp structures and robust process design validated across temperature and process corners.

Does the CS8371ET7 require external output capacitors for stability?

The CS8371ET7's 8.0 V output uses NOCAP technology and is stable without any external output capacitor under steady-state or slow-switching loads; however, large transient loads (e.g., microprocessor bursts) may benefit from a small storage capacitor. The 5.0 V output employs a Darlington NPN structure and is inherently stable with or without external capacitance. Neither output requires ESR-tuned capacitors, simplifying design and reducing BOM cost. The CS8371ET7 datasheet provides guidance on optional capacitor selection based on load dynamics.

How does the Sense pin (Pin 5) improve regulation accuracy in the CS8371ET7?

The Sense pin (Pin 5) provides remote feedback for the 8.0 V output, allowing the CS8371ET7 to monitor voltage directly at the load rather than at the IC's VOUT1 pin. This compensates for IR drop across PCB traces or connectors between the regulator and load, maintaining ±5% output accuracy at the point-of-load even with trace resistances up to ~100 mΩ. It must be connected to the load-side of the trace being compensated and kept away from noisy ground returns to preserve measurement fidelity. The CS8371ET7 uses this signal exclusively for its primary regulator loop.

What is the quiescent current of the CS8371ET7 in sleep mode?

In sleep mode - defined as both ENABLE1 and ENABLE2 held low - the CS8371ET7 draws less than 10 µA total quiescent current (typical 0.2 µA, max 10 µA) at VCC = 14 V and TA = 25 °C. This ultra-low standby current prevents excessive battery drain during vehicle ignition-off periods, supporting extended parking modes in modern automotive electronics. The CS8371ET7 achieves this via internal bias circuit shutdown and leakage-optimized transistor sizing across process corners and temperature ranges.

Can the CS8371ET7's two outputs be enabled simultaneously or independently?

Yes - the CS8371ET7 provides fully independent ENABLE control: ENABLE1 (Pin 1) controls only the 8.0 V output, and ENABLE2 (Pin 2) controls only the 5.0 V output. Either output can be active while the other is disabled, enabling flexible power sequencing (e.g., powering logic before motors), fault isolation, and dynamic load management. Both inputs accept standard CMOS logic levels (high ≥2.0 V, low ≤0.8 V) and draw negligible current (<±150 µA). The CS8371ET7 does not require simultaneous enablement and operates correctly with any combination of ENABLE states.