onsemi KSH44H11TF

Overview

KSH44H11TF from ON Semiconductor is an NPN epitaxial silicon power transistor in TO-252 (DPAK) package, rated for 80 V V_CEO, 8 A DC collector current, and 20 W collector dissipation at T_C = 25°C. It delivers low 1 V V_CE(sat) at I_C = 8 A / I_B = 0.4 A and supports fast switching with t_ON = 300 ns, t_F = 140 ns - used in DC-DC converter output stages and switching regulator power switches.

For engineers reviewing the KSH44H11TF datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO rating, saturation voltage under high-current drive, SOA compliance at elevated case temperatures, and DPAK thermal performance in surface-mount power designs.

Technical Context

This device operates as a general-purpose NPN bipolar junction transistor optimized for medium-power switching. Its epitaxial base structure enables stable h_FE of 40–60 across 2–4 A collector current and supports f_T = 50 MHz for moderate-frequency switching control.

Designed for surface-mount implementation in TO-252, it features a three-terminal configuration (Base–Collector–Emitter) with electrically similar characteristics to the legacy KSE44H series. Thermal derating begins at T_C > 25°C, with linear reduction to zero dissipation at T_C = 125°C per Figure 3.

Key Specifications

Pinout & Package

Package: TO-252-3L (DPAK), surface-mount, single-ended heat sink tab (Collector-connected). Standard lead form with gull-wing terminations.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD44H11T4 and STN44H11, the KSH44H11TF offers superior current capability and lower saturation voltage, making it optimal for high-efficiency 5–8 A switching applications where thermal headroom is constrained and base drive strength is limited.

Availability

KSH44H11TF is available at Aetrix Electronics and suitable for switching regulators, DC-DC converters, and power amplifiers requiring stable component supply with consistent DPAK packaging and traceable lot history.

Supply support for KSH44H11TF 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 is a global semiconductor manufacturer specializing in power management, analog, sensors, and discrete devices for automotive, industrial, and cloud power applications.

The KSH44H11TF belongs to ON Semiconductor's legacy Fairchild power transistor portfolio, designed specifically for cost-sensitive, medium-power switching applications demanding reliability and thermal robustness in surface-mount formats.

FAQ

What is the maximum continuous collector current rating for KSH44H11TF?

The KSH44H11TF is rated for 8 A DC collector current at case temperature T_C = 25°C. Derating is required above this temperature - for example, at T_C = 100°C, the maximum allowable I_C drops to approximately 4.5 A per the linear derating curve in the datasheet. This rating assumes proper PCB copper area and thermal vias for heat transfer. The KSH44H11TF must not be operated beyond its Safe Operating Area boundaries defined in Figure 2.

Does KSH44H11TF have a built-in base-emitter resistor?

No, the KSH44H11TF is a standard three-terminal NPN bipolar transistor without any integrated base resistors. It requires external base drive circuitry - typically a current-limiting resistor or active driver - to establish proper I_B for saturation. This distinguishes it from digital transistors (e.g., NSBA143 series) and confirms its use in discrete switching amplifier topologies. The KSH44H11TF datasheet specifies base drive requirements explicitly for V_CE(sat) validation.

What is the thermal resistance R_θJC of KSH44H11TF?

The junction-to-case thermal resistance (R_θJC) for KSH44H11TF in TO-252 package is 1.25°C/W, calculated from P_C = 20 W and ΔT = 25°C (T_J − T_C). This value is derived directly from the absolute maximum ratings table and confirmed by thermal characterization in Fairchild Application Note AN-1027. Effective PCB layout using ≥1.5 cm² 2 oz copper with thermal vias is required to realize this R_θJC in practice. The KSH44H11TF thermal performance depends critically on solder joint quality and heatsink interface.

Can KSH44H11TF replace KSE44H in existing designs?

Yes, the KSH44H11TF is electrically similar to the KSE44H and shares identical V_CEO, I_C, and V_CE(sat) specifications. However, the KSH44H11TF uses TO-252 (DPAK) while KSE44H uses TO-220, so mechanical redesign is required. Pinout differs: KSE44H has E-B-C order, whereas KSH44H11TF is B-C-E. Layout adaptation and thermal validation are necessary before drop-in substitution. The KSH44H11TF offers improved surface-mount manufacturability over the through-hole KSE44H.

What is the safe operating area (SOA) limit for KSH44H11TF at 100 V?

The KSH44H11TF is not rated for operation at 100 V - its absolute maximum V_CEO is 80 V. At V_CE = 80 V, the SOA curve (Figure 2) limits single-pulse current to ≤2.5 A for 10 ms duration. Exceeding 80 V risks avalanche breakdown and permanent damage. For 100 V bus applications, a higher-voltage device such as MJD122 (V_CEO = 100 V) should be selected instead. The KSH44H11TF SOA must be evaluated strictly within its 80 V ceiling.