onsemi CS5205-1GDP3

Overview

CS5205-1GDP3 from onsemi is an adjustable-output linear regulator delivering 5.0 A with ±1.0% output voltage accuracy, 1.2 V dropout at full load, and integrated thermal shutdown, overcurrent, and safe operating area (SOA) protection. It operates from 1.25 V to 13 V output range using two external resistors and targets post-regulation and microprocessor supply applications requiring low-voltage operation and fast transient response.

For engineers reviewing the CS5205-1GDP3 datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at 5 A, reference voltage stability over temperature, quiescent current under full load, SOA protection behavior under high VIN–VOUT differentials, and D2PAK-3 thermal performance in high-power PCB layouts.

Technical Context

The CS5205-1GDP3 uses a composite PNP-NPN output stage enabling low dropout and high current capability while maintaining loop stability with ≥22 µF tantalum output capacitance. Its error amplifier maintains a precise 1.254 V (typ) reference between VOUT and ADJ pins, with adjust pin current ≤100 µA contributing measurable error in precision resistor-divider designs.

Protection circuitry dynamically reduces available output current as VIN–VOUT increases-enforcing SOA limits-and triggers thermal shutdown at 150°C with 25°C hysteresis. The device requires Kelvin-sense connection at the output pin for specified load regulation and is optimized for use with external capacitors that provide controlled ESR to ensure stability.

Key Specifications

Pinout & Package

D2PAK-3 surface-mount package (Case 418AB) with exposed tab electrically connected to VOUT for enhanced thermal conduction. Requires thermal pad soldering and isolation if VOUT is not chassis-ground referenced.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable high-current linear regulator applications.

Compared with LT1084CT-1.2#PBF and TL783CKTTR, the CS5205-1GDP3 delivers 5× higher output current, integrated SOA enforcement, and lower dropout in the same D2PAK-3 footprint-making it the sole option for thermally constrained, high-current adjustable regulation without external protection circuitry.

Availability

CS5205-1GDP3 is available at Aetrix Electronics and suitable for microprocessor core supplies, FPGA I/O regulation, industrial PLC power modules, and test equipment reference supplies requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for CS5205-1GDP3 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, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The CS5205-1GDP3 belongs to onsemi's high-current linear regulator product line, engineered specifically for post-regulation of switching supplies in compute, automation, and instrumentation systems where low dropout, fast transient response, and robust fault protection are mandatory.

FAQ

What is the minimum recommended output capacitor for stable operation of the CS5205-1GDP3?

The CS5205-1GDP3 requires a minimum 22 µF tantalum output capacitor for guaranteed stability across all operating conditions. Aluminum electrolytic capacitors may be used but exhibit larger ESR variation at low temperatures; ceramic capacitors are not recommended due to near-zero ESR causing potential oscillation. For improved transient response in microprocessor applications, parallel combinations of tantalum and low-ESR ceramic capacitors are advised-always placed as close as possible to the VOUT and GND pins of the CS5205-1GDP3.

Does the CS5205-1GDP3 support remote voltage sensing?

No, the CS5205-1GDP3 is a three-terminal adjustable regulator without dedicated sense pins. Load regulation is limited by PCB trace resistance between the device's VOUT pin and the load. To minimize voltage drop, connect the R1 resistor of the feedback divider directly to the VOUT pin-not the load-and place the CS5205-1GDP3 as close as possible to the load. For applications demanding <0.1% load regulation, external four-wire sensing with an op-amp error amplifier is required, as the CS5205-1GDP3 itself does not support Kelvin sensing.

What thermal interface materials are recommended for the CS5205-1GDP3 D2PAK-3 package?

Thermal compound must be used between the CS5205-1GDP3's exposed VOUT tab and the heatsink or PCB copper pour. Use non-conductive thermal pads (e.g., Bergquist Sil-Pad 1000) if electrical isolation is required, or conductive thermal grease (e.g., Wakefield-Vette Wake-Gel 300) when the heatsink is tied to the output rail. Avoid air gaps: apply uniform pressure during assembly and verify thermal resistance junction-to-ambient (RJA) remains ≤50°C/W per datasheet specifications. Do not rely solely on solder paste adhesion-the CS5205-1GDP3 demands intentional thermal interface design.

How does the SOA protection in the CS5205-1GDP3 affect output current under high input-output differential?

The CS5205-1GDP3's SOA protection reduces maximum allowable output current as VIN–VOUT increases-e.g., at 8 V differential, current may be limited to ~3.5 A instead of 5.0 A-to prevent exceeding safe power dissipation limits. This behavior is inherent and automatic; no external components are needed. Designers must consult the SOA curve in Figure 3 of the datasheet and size heatsinks accordingly. Unlike simple current limiting, SOA protection preserves regulation until the thermal or current threshold is reached, making the CS5205-1GDP3 more robust than fixed-limited alternatives in variable-input applications.

Can the CS5205-1GDP3 be used without an input capacitor?

No, the CS5205-1GDP3 requires a minimum 10 µF input capacitor placed within 10 mm of the VIN and GND pins. Without it, the device exhibits instability, increased ripple susceptibility, and risk of oscillation during load transients. Tantalum or aluminum electrolytic capacitors are preferred; ceramic capacitors alone are insufficient due to low ESR. The input capacitor also absorbs surge currents from upstream sources and prevents voltage droop during sudden load steps. Omitting this capacitor violates the test conditions under which all CS5205-1GDP3 specifications-including dropout voltage and ripple rejection-are guaranteed.