onsemi KSD1588OTU

Overview

KSD1588OTU from onsemi is an NPN epitaxial silicon transistor designed for low-frequency power amplification and low-speed switching applications, with V_CEO = 60 V, I_C = 7 A (DC), P_C = 30 W at T_C = 25 °C, and h_FE ≥ 40 at I_C = 3 A - used in audio output stages and relay drivers.

For engineers reviewing the KSD1588OTU datasheet, pinout, applications, or equivalent options, key selection criteria include safe operating area (SOA) compliance at 5 A/10 V, V_CE(sat) ≤ 0.5 V at I_C = 5 A/I_B = 0.5 A, thermal derating above 25 °C case temperature, and complementary pairing with KSB1097 for push-pull configurations.

Technical Context

This device operates as a medium-power bipolar junction transistor with fixed NPN polarity and DC current gain graded per h_FE1 classification (Y-grade: 100–200). It requires external base current limiting and heatsinking due to its TO-220 Fullpack package's thermal resistance dependence on PCB copper area.

The KSD1588OTU exhibits defined saturation behavior: V_CE(sat) ≤ 0.5 V and V_BE(sat) ≤ 1.5 V under pulsed conditions (PW ≤ 350 µs, duty ≤ 2%), enabling predictable on-state loss in linear and switching modes up to 60 V collector swing.

Key Specifications

Pinout & Package

Package: TO-220 Fullpack (Case 221AT), insulated back, 3-lead, Pb-free, mounted via single screw hole centered on tab.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN power transistor applications.

Compared with MJD127G and 2SC5200, the KSD1588OTU offers optimal balance of voltage margin (60 V), current capability (7 A), thermal performance (30 W @ T_C = 25 °C), and through-hole TO-220 compatibility - making it ideal for cost-sensitive, medium-power linear and switching designs where layout flexibility and serviceability matter.

Availability

KSD1588OTU is available at Aetrix Electronics and suitable for audio amplifiers, relay drivers, DC motor controllers, and linear regulator pass elements requiring stable component supply across industrial and consumer production cycles.

Supply support for KSD1588OTU 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, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and IoT applications.

The KSD1588OTU belongs to onsemi's discrete power transistor product line, engineered for robust low-frequency amplification and switching in cost-sensitive, thermally constrained systems where reliability and manufacturability are critical.

FAQ

What is the h_FE grade for KSD1588OTU?

The "O" suffix in KSD1588OTU indicates the h_FE1 classification grade: 80–120 at V_CE = 1 V and I_C = 3 A. This is confirmed in the marking diagram and Electrical Characteristics table of the official onsemi datasheet (KSD1588/D, Rev. 2). The KSD1588OTU delivers predictable DC gain for bias network design without requiring binning or test screening.

Is KSD1588OTU pin-compatible with KSD1588YTU?

Yes - both KSD1588OTU and KSD1588YTU share identical TO-220 Fullpack (Case 221AT) packaging, pinout (Base–Collector–Emitter), and mechanical dimensions. The only difference is h_FE grading: "O" = 80–120, "Y" = 100–200. No PCB or footprint changes are needed when substituting KSD1588OTU for KSD1588YTU in existing designs.

Does KSD1588OTU require a heatsink in continuous 5 A operation?

Yes - at I_C = 5 A and V_CE ≈ 2 V (typical linear operation), power dissipation exceeds 10 W. Since KSD1588OTU's P_C = 30 W is rated only at T_C = 25 °C, a heatsink maintaining case temperature ≤ 60 °C is mandatory. Thermal calculations must account for junction-to-case resistance (typically ~1.5 °C/W) and interface material performance.

Can KSD1588OTU replace KSD1588 in legacy designs?

Yes - KSD1588OTU is a Pb-free (RoHS-compliant) version of the original KSD1588, with identical electrical specifications, TO-220 Fullpack packaging, and pinout. The "TU" suffix denotes tape-and-reel or tube packaging per onsemi's ordering nomenclature; no functional or thermal differences exist between KSD1588OTU and non-Pb-free KSD1588 variants.

What is the safe operating area (SOA) limit for KSD1588OTU at 100 µs pulse width?

Per Figure 4 in the KSD1588/D datasheet, the SOA limit for KSD1588OTU at 100 µs pulse width is approximately 12 A at V_CE = 10 V and 8 A at V_CE = 20 V. These boundaries are defined by second breakdown limits and must be respected in pulse-switching applications to prevent localized thermal runaway and permanent damage to the KSD1588OTU die.