onsemi KA7824E

Overview

KA7824E from ON Semiconductor is a fixed-output, 3-terminal, 1 A positive linear voltage regulator delivering a nominal 24 V output with ±4% tolerance at 25°C, dropout voltage of 2 V at 1 A, and integrated thermal overload, short-circuit, and safe operating area protection. It operates across –40°C to +125°C and is commonly used in industrial power supplies, battery chargers, and embedded control systems requiring stable 24 V rail generation from unregulated DC inputs.

For engineers reviewing the KA7824E datasheet, pinout, applications, or equivalent options, key selection considerations include input voltage range (27–38 V), load regulation (≤240 mV over 250–750 mA), ripple rejection (50–67 dB at 120 Hz), output noise (120 μV RMS), and TO-220 package thermal resistance (R_θJC = 5°C/W).

Technical Context

The KA7824E implements a classic series-pass linear regulator architecture with an internal bandgap reference, error amplifier, and NPN pass transistor. Protection circuitry includes foldback current limiting, thermal shutdown triggered at ~150°C junction temperature, and SOA monitoring to prevent second breakdown during transient overloads.

It requires minimal external components: a 0.33 μF input capacitor (CI) and 0.1 μF output capacitor (CO) for stability per the test circuit. Performance is specified across –40°C to +125°C junction temperature, with line regulation tested over VI = 30–36 V and load regulation over IO = 250–750 mA.

Key Specifications

Pinout & Package

KA7824E is housed in a TO-220 (dual-gauge) package with standard 3-terminal configuration: Input (Pin 1), Ground (Pin 2), Output (Pin 3). The metal tab is electrically connected to Pin 2 (GND) and serves as the primary thermal path to heatsink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7824CT and KA7824AE, the KA7824E trades tighter output tolerance and slightly higher noise for guaranteed operation down to –40°C - making it the sole choice among these three for wide-temperature industrial deployments where cold-start reliability is non-negotiable.

Availability

KA7824E is available at Aetrix Electronics and suitable for industrial PLC power supplies, battery charger bias rails, and embedded motor control auxiliary rails requiring stable component supply, long-lifecycle support, and traceable sourcing from authorized channels.

Supply support for KA7824E 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

ON Semiconductor (formerly Fairchild Semiconductor) is a global semiconductor manufacturer specializing in power management, analog, and discrete devices for automotive, industrial, and cloud infrastructure markets.

The KA78XXE series was designed as cost-effective, robust 3-terminal linear regulators for general-purpose industrial power conversion - emphasizing ruggedness, ease of use, and broad temperature operation over ultra-low noise or ultra-high efficiency.

FAQ

What is the maximum input voltage rating for the KA7824E?

The KA7824E has an absolute maximum input voltage of 40 V when the output voltage is 24 V, as specified in the Absolute Maximum Ratings table. Operation above this level risks permanent device damage. For reliable long-term use, the recommended input range is 27 V to 38 V, ensuring sufficient headroom for ripple and transients while maintaining regulation.

Does the KA7824E require external capacitors, and what values are recommended?

Yes, the KA7824E requires external capacitors for stability: a minimum 0.33 μF ceramic capacitor at the input (Pin 1) and a minimum 0.1 μF ceramic capacitor at the output (Pin 3), placed as close as possible to the respective pins. These values are validated in the test circuit and prevent oscillation, especially under dynamic load conditions.

Can the KA7824E be used in parallel to increase output current?

No, the KA7824E is not designed for parallel operation. Its output voltage tolerance (±4%) and lack of current-sharing features mean paralleling units will cause unequal current distribution, thermal runaway, and potential failure. For >1 A requirements, use a higher-current regulator or a switching solution instead.

What thermal performance can be expected from the KA7824E in a TO-220 package?

In its TO-220 package, the KA7824E has a junction-to-case thermal resistance of 5°C/W. With a properly mounted heatsink (e.g., 10°C/W sink-to-ambient), it can sustain 1 A output at 24 V with ~2 V dropout (2 W dissipation) while keeping junction temperature within the –40°C to +125°C range - assuming ambient ≤75°C and adequate airflow.

Is the KA7824E pin-compatible with other 78xx-series regulators like the LM7824?

Yes, the KA7824E uses the industry-standard 3-pin TO-220 pinout (Input–GND–Output), matching LM7824, MC7824, and other 78xx-family regulators. However, differences in thermal shutdown threshold, short-circuit current, and output tolerance mean direct substitution should be verified for the specific application's safety and accuracy requirements.