onsemi CS52015-3GST3

Overview

CS52015-3GST3 from onsemi is a fixed-output 3.3 V, 1.5 A linear regulator in SOT-223 package, featuring ±1.5% output accuracy over temperature, 1.05 V typical dropout at full load, fast transient response, and integrated over-current and thermal shutdown protection-designed for microprocessor post-regulation and low-voltage embedded power rails.

For engineers reviewing the CS52015-3GST3 datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage under 1.4 V at 1.5 A, quiescent current ≤10 mA at full load, thermal shutdown at 150–210°C, and compatibility with 22 µF tantalum output capacitance for stable operation in high-dI/dt digital loads.

Technical Context

The CS52015-3GST3 employs a composite PNP-NPN pass transistor architecture optimized for low-dropout operation and fast loop response. Its error amplifier drives the output stage with internal bandgap reference and thermal shutdown comparator, enabling stable regulation across −40°C to +70°C ambient with <0.02% line regulation and <0.4% load regulation.

It requires an external 22 µF tantalum output capacitor for stability-ceramic capacitors alone are discouraged due to near-zero ESR-induced instability. The device's case is electrically connected to VOUT, necessitating isolation considerations in PCB layout when mounting to heatsinks.

Key Specifications

Pinout & Package

SOT-223 package (Case 318E), surface-mount, 3-pin, tab-connected to VOUT. Requires thermal pad soldering to PCB copper for effective heat dissipation; R_JA = 156°C/W typical without heatsink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1086CM-3.3 and TPS7A4700RGWR, the CS52015-3GST3 delivers superior dropout performance at 1.5 A while maintaining SOT-223 compatibility and lower BOM cost-making it optimal for industrial and embedded digital power where efficiency, thermal margin, and footprint are prioritized over ultra-low IQ or wideband PSRR.

Availability

CS52015-3GST3 is available at Aetrix Electronics and suitable for microprocessor core supplies, FPGA I/O regulation, industrial PLC digital I/O modules, and medical sensor interface circuits requiring stable component supply and long-term production continuity.

Supply support for CS52015-3GST3 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 electronics, with leadership in power management, analog, and sensing technologies.

The CS52015-3GST3 belongs to onsemi's linear regulator product line designed specifically for high-current, low-dropout post-regulation in space-constrained embedded and industrial systems-emphasizing thermal robustness, transient performance, and ease of use with standard capacitors.

FAQ

What is the maximum input voltage rating for the CS52015-3GST3?

The CS52015-3GST3 has an absolute maximum input voltage of 7.0 V. Operation above this level risks permanent damage. For reliable long-term use, design input voltage to remain ≤6.5 V with appropriate derating for transients and ripple-especially important given its 1.05 V typical dropout at 1.5 A output current.

Does the CS52015-3GST3 require an external output capacitor, and what type is recommended?

Yes, the CS52015-3GST3 requires an external output capacitor for stability. A 22 µF tantalum capacitor is specified and validated in the datasheet; aluminum electrolytic is acceptable but less stable at low temperatures. Ceramic capacitors alone are not recommended due to near-zero ESR causing potential oscillation-CS52015-3GST3 relies on capacitor ESR for phase compensation.

Is the thermal pad (tab) of the CS52015-3GST3 electrically connected, and how should it be handled?

Yes-the tab of the CS52015-3GST3 in SOT-223 package is internally connected to the VOUT pin. It must be soldered to a dedicated copper pour tied to the 3.3 V output net. If a heatsink is used, electrical isolation (e.g., mica washer + thermal grease) is mandatory to prevent shorting. Failure to isolate may cause catastrophic failure or system-level latch-up.

What is the load regulation specification for the CS52015-3GST3, and why does it matter?

The CS52015-3GST3 exhibits ≤0.4% load regulation (0.04% typical) from 10 mA to 1.5 A output current. This means output voltage varies by no more than ±13.2 mV across full load-critical for maintaining logic-level margins in microprocessors and FPGAs. Poor load regulation could cause reset events or timing violations during dynamic current changes.

Can the CS52015-3GST3 be used as a direct replacement for LT1086 regulators in existing designs?

The CS52015-3GST3 is explicitly stated as pin-compatible with the LT1086 family and offers lower dropout voltage. However, it is not a guaranteed drop-in replacement without validation: output capacitor requirements differ (tantalum vs. LT1086's broader capacitor tolerance), and thermal characteristics (R_JA = 156°C/W) demand careful PCB copper area review. Always verify transient response and thermal rise in the target application before substitution.