onsemi KSB772YSTSTU

Overview

KSB772YSTSTU from onsemi (formerly Fairchild Semiconductor) is a PNP epitaxial silicon power transistor in TO-126 package, rated for -30 V V_CEO, -3 A I_C (DC), and 10 W P_C at T_C=25°C, with h_FE of 60–400 (class Y/G) and f_T = 80 MHz - used in audio frequency power amplification and low-speed switching circuits.

For engineers reviewing the KSB772YSTSTU datasheet, pinout, applications, or equivalent options, key selection considerations include its complementary pairing with KSD882, saturation voltage under -2 A/-0.2 A drive, thermal resistance (R_θJC = 13.5°C/W), and discontinued status requiring legacy design support planning.

Technical Context

This PNP bipolar junction transistor operates in linear amplification and saturated switching modes. Its DC current gain spans two classes (Y: 160–320; G: 200–400) at V_CE = -2 V, with V_CE(sat) ≤ -0.5 V and V_BE(sat) ≤ -2.0 V at I_C = -2 A / I_B = -0.2 A.

The device features f_T = 80 MHz at V_CE = -5 V / I_E = -0.1 A and C_ob = 55 pF at V_CB = -10 V / f = 1 MHz, supporting audio-band amplification and moderate-speed switching up to ~100 kHz with safe operating area (SOA) defined for pulse widths down to 100 µs.

Key Specifications

Pinout & Package

Package: TO-126 (TSSTU variant), through-hole, 3-terminal plastic package with emitter-collector-base pin assignment (pin 1 = Emitter, pin 2 = Collector, pin 3 = Base). Dimensions per MKT-TO126AArev2: terminal length D = 3.45–4.05 mm, E = 6.45–7.45 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD772T4G and PN3569, KSB772YSTSTU offers superior thermal performance (R_θJC = 13.5°C/W) and higher continuous power handling (10 W) in through-hole TO-126, making it suitable for legacy repair and medium-power linear applications where SMT conversion is impractical.

Availability

KSB772YSTSTU is available at Aetrix Electronics and suitable for audio amplifier repair, industrial relay driver replacement, and legacy linear regulator maintenance requiring stable component supply and traceable sourcing.

Supply support for KSB772YSTSTU 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 Fairchild Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The KSB772YSTSTU belongs to onsemi's legacy bipolar power transistor family designed for audio frequency amplification and low-speed switching in industrial and consumer equipment - emphasizing robustness, thermal reliability, and complementary pairing.

FAQ

What is the pin configuration of KSB772YSTSTU?

KSB772YSTSTU uses TO-126 package with pin 1 = Emitter, pin 2 = Collector, pin 3 = Base. This arrangement is standardized across the KSB772 series and confirmed in the official onsemi mechanical drawing MKT-TO126AArev2. The TSSTU suffix denotes specific terminal length tolerances (D = 3.45–4.05 mm, E = 6.45–7.45 mm), critical for automated insertion compatibility.

Is KSB772YSTSTU still recommended for new designs?

No - KSB772YSTSTU is officially discontinued and not recommended for new designs per onsemi documentation (Rev. 3, July 2025). It remains available for legacy repair and obsolescence mitigation. Engineers designing new systems should consult onsemi for modern alternatives such as the MJD772T4G or NSS series, while KSB772YSTSTU continues to be stocked by Aetrix Electronics for maintenance programs.

What is the h_FE range for KSB772YSTSTU?

KSB772YSTSTU is binned into h_FE classes Y (160–320) and G (200–400) at V_CE = -2 V and I_C = -1 A. The "YSTSTU" suffix corresponds to class Y or G depending on lot; actual h_FE must be verified per unit via test data or datasheet classification table. This binning ensures consistent biasing in production amplifiers without individual trimming.

How does KSB772YSTSTU compare to its NPN complement KSD882?

KSB772YSTSTU and KSD882 form a complementary pair: both share identical voltage/current ratings (V_CEO = -30 V / +30 V, I_C = -3 A / +3 A), TO-126 packaging, and thermal characteristics (R_θJC = 13.5°C/W), enabling symmetrical push-pull output stages. Their matched h_FE profiles minimize crossover distortion in Class AB amplifiers when biased correctly.

What thermal derating applies to KSB772YSTSTU at elevated case temperatures?

KSB772YSTSTU's power dissipation must be linearly derated above T_C = 25°C at 0.074 W/°C (10 W ÷ 135°C rise to T_J = 150°C), per the datasheet derating curve (Figure 8). At T_C = 100°C, maximum allowable P_C drops to approximately 4.5 W. This requires careful heatsink selection and ambient temperature monitoring in enclosed industrial environments.