onsemi CS5233-3GDPR5

Overview

CS5233-3GDPR5 from onsemi is a dual-input 3.3 V linear regulator with auxiliary PFET drive control, designed for glitch-free power switching among VIN (5 V main), VSB (5 V standby), and 3.3 VAUX sources. It delivers up to 1.5 A from VIN in D2PAK-5 package with ±2% output accuracy, integrated current limiting, thermal shutdown with 25°C hysteresis, and reverse current protection (<1 mA). It targets PCI NIC ASIC power delivery meeting Intel's "Instantly Available" ACPI requirements.

For engineers reviewing the CS5233-3GDPR5 datasheet, pinout, applications, or equivalent options, key selection criteria include input source arbitration logic, AuxDrv timing response (1–10 µs turn-on), dropout behavior under 500 mA/1.5 A loads, and thermal resistance (R_JA = 10–50°C/W) for heatsink design in desktop and PCMCIA systems.

Technical Context

The CS5233-3GDPR5 implements a composite NPN-PNP pass transistor architecture enabling low-dropout operation while maintaining stability with ≥10 µF/ESR <1.0 Ω output capacitance. Its dual-input comparator circuitry monitors VIN and VSB with 100 mV hysteresis and precise thresholds (4.25–4.65 V turn-on/off), ensuring reliable source handoff without output glitches.

AuxDrv operates as an open-drain-like control output pulled high via internal 5–25 kΩ resistor when either VIN or VSB exceeds 4.4 V; it sinks up to 50 mA and drives external PFET gate to connect 3.3 VAUX during input loss. The IC integrates bandgap reference, error amplifier, thermal shutdown sensor near the pass device, and current limit sensing per input path.

Key Specifications

Pinout & Package

CS5233-3GDPR5 is housed in a D2PAK-5 (TO-263) thermally enhanced surface-mount package with exposed tab (pin 3) serving as GND and primary heat path. The 5-lead configuration supports high-current operation and simplified thermal layout on 2+ oz copper PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CS5233-3GDPR5, CS5231-3GDP5 reduces maximum current and removes VSB-only support, while TPS7A4700RGWR shifts system complexity to external components-making CS5233-3GDPR5 the only single-chip solution for ACPI-compliant dual-source 3.3 V regulation with auxiliary backup.

Availability

CS5233-3GDPR5 is available at Aetrix Electronics and suitable for PCI NICs, desktop motherboard power domains, and PCMCIA interface cards requiring stable component supply, long-term lifecycle support, and production-ready thermal performance.

Supply support for CS5233-3GDPR5 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 delivering energy-efficient, high-performance silicon solutions for automotive, industrial, cloud, and IoT applications.

The CS5233-3GDPR5 belongs to onsemi's power management linear regulator family, engineered specifically for ACPI-compliant computing platforms requiring seamless multi-rail power arbitration and auxiliary backup without external control logic.

FAQ

What is the maximum continuous output current for CS5233-3GDPR5 when powered from VIN?

The CS5233-3GDPR5 delivers up to 1.5 A continuously from VIN when mounted in its D2PAK-5 package with adequate PCB copper and thermal relief. This rating assumes VIN ≥4.75 V, ambient temperature ≤70°C, and proper heatsinking per R_JA = 10–50°C/W. Exceeding 1.5 A triggers current limit, pulling VOUT out of regulation.

Does CS5233-3GDPR5 support operation from VSB only, and what is its output capability in that mode?

Yes, CS5233-3GDPR5 supports standalone VSB operation, delivering up to 500 mA at 3.3 V ±2%. This mode activates when VIN is absent or below 4.25 V and VSB exceeds 4.35 V. Both D2PAK-5 and SOIC-8 packages share this 500 mA VSB-only rating, as specified in Electrical Characteristics Table footnote 3.

How does the AuxDrv pin behave during input source transitions, and what is its timing specification?

The AuxDrv pin pulls high (≥3.75 V) when VIN or VSB exceeds 4.65 V and goes low (<0.4 V) when both fall below 4.4 V. Its turn-on response time is 1.0–10 µs; turn-off is 20–40 µs. A built-in 20 µs delay prevents chatter during simultaneous regulator enable/PFET disable transitions, as documented in Applications Information.

Can CS5233-3GDPR5 be used without an external PFET, and what functionality remains active?

Yes, CS5233-3GDPR5 functions fully as a dual-input 3.3 V LDO without the external PFET. The AuxDrv pin remains unconnected or pulled high externally, and regulation continues from VIN or VSB. The auxiliary backup feature is simply inactive-no damage or fault occurs. All protections (current limit, thermal shutdown, reverse current) remain fully operational.

What are the minimum output capacitor requirements for stable operation of CS5233-3GDPR5?

CS5233-3GDPR5 requires a minimum 10 µF output capacitor with ESR <1.0 Ω for guaranteed loop stability across all operating conditions. Tantalum or low-ESR polymer capacitors are recommended. Placement must be adjacent to VOUT and GND pins; remote placement or undersized capacitance risks oscillation or poor transient response, as shown in Figure 7.