onsemi CS403GTHA5

Overview

CS403GTHA5 from onsemi is a 5.0 V ±3% fixed-output linear regulator in TO-220-5 (horizontal) package, designed as a post-regulator for switching power supplies. It delivers up to 750 mA output current with 1.4 V typical dropout at full load, 4.0 mA quiescent current at I_OUT = 750 mA, and features active delayed reset with 20 ms typical delay using a 100 nF capacitor.

For engineers reviewing the CS403GTHA5 datasheet, pinout, applications, or equivalent options, key selection considerations include its PNP–NPN output stage enabling low-dropout operation without high supply current, precise reset threshold hysteresis (10–50 mV), and supply rejection optimization via internal reference switching from VIN to VOUT at regulation.

Technical Context

The CS403GTHA5 integrates a low-drift bandgap reference and error amplifier to maintain tight output voltage accuracy across temperature and load. Its RESET circuit includes dual hysteresis comparators (VRT(ON)/VRT(OFF)), latched delay capacitor discharge, and open-collector NPN output capable of sinking ≥1.6 mA at 0.4 V.

Supply rejection is enhanced by dynamically switching the internal reference node from VIN to VOUT once nominal output is reached, improving PSRR to 70 dB at 120 Hz. The device operates over –40°C to +150°C junction temperature and supports input voltages from –0.75 V to 18 V.

Key Specifications

Pinout & Package

CS403GTHA5 uses a 5-lead TO-220 package (Case 314A, horizontal lead form) with tab connected to GND. Thermal performance relies on proper heatsink mounting to the metal tab.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV70250DBVR and MAX809SEUR+T, the CS403GTHA5 uniquely combines 750 mA regulation, low-dropout operation, and programmable reset in one TO-220 package-enabling simplified power tree design where both clean 5 V delivery and deterministic reset timing are required.

Availability

CS403GTHA5 is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, and automotive body electronics requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for CS403GTHA5 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 is a global semiconductor supplier delivering energy-efficient silicon solutions for automotive, industrial, cloud, and IoT applications.

The CS403GTHA5 belongs to onsemi's precision linear regulator family, engineered specifically for post-regulation in switching power supplies where low noise, high accuracy, and integrated reset supervision are critical.

FAQ

What is the maximum input voltage rating for CS403GTHA5?

The CS403GTHA5 has an absolute maximum forward input voltage of 18 V. Operation beyond this limit risks permanent damage. For reliable long-term use, the recommended operating input range is 7.0 V to 10 V per the electrical characteristics table, with dropout performance optimized in that window. The device also tolerates –0.75 V on VIN, supporting safe handling during reverse-bias transients.

How does the CS403GTHA5 generate its reset signal?

The CS403GTHA5 uses an internal low-voltage inhibit comparator monitoring VOUT against a 4.75 V falling threshold (VRTL). When VOUT drops below this level, the open-collector RESET pin pulls low. A separate delay circuit-charged via Pin 4 with user-selected capacitor-adds 10–30 ms hysteresis to prevent false resets during brief dips. The CS403GTHA5 implements latched discharge so the capacitor fully resets each time VOUT falls out of regulation.

Can CS403GTHA5 operate without an output capacitor?

No, the CS403GTHA5 requires an output capacitor (10–100 µF) for loop stability, as confirmed in the Applications Notes section. Tantalum or aluminum electrolytic types are mandatory due to their essential ESR (50–200 mΩ); ceramic or film capacitors cause oscillation. The CS403GTHA5 datasheet explicitly warns against zero-ESR configurations and provides test circuit COUT = 10 µF as baseline.

What thermal management is required for CS403GTHA5 at 750 mA output?

At 750 mA with 8.5 V input and 5.0 V output, CS403GTHA5 dissipates ~2.6 W. With R_ΘJA = 50°C/W, junction temperature rise would exceed 130°C above ambient-exceeding the 150°C max. Therefore, a heatsink reducing effective R_ΘJA to ≤30°C/W is required. Mounting the TO-220 tab directly to a copper pour or external heatsink is mandatory for full-load operation at room temperature.

Is CS403GTHA5 pin-compatible with other CS403 variants like CS403GT5 or CS403GTVA5?

Yes, all CS403 variants-including CS403GTHA5, CS403GT5, and CS403GTVA5-share identical pinout (VIN, RESET, GND, Delay, VOUT), electrical specifications, and internal functionality. The suffix differences denote only lead orientation (horizontal vs. vertical vs. straight) and packaging configuration (TO-220 Case 314A/314K/314D); no electrical or thermal parameter varies between them.