onsemi KSA708YBU

Overview

KSA708YBU from onsemi is a PNP epitaxial silicon transistor designed for low-frequency amplification and medium-speed switching applications, with −80 V collector-base voltage, −700 mA maximum collector current, 800 mW power dissipation, and DC current gain (hFE) of 120–240 at −50 mA collector current. It serves as a complement to the NPN KSC1008 in push-pull amplifier stages and relay driver circuits.

For engineers reviewing the KSA708YBU datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 3-lead Pb-free package, verified V_CEO = −60 V rating, saturation voltage performance (V_CE(sat) ≤ 0.7 V at −500 mA), f_T = 50 MHz bandwidth, and compatibility with discrete BJT-based biasing and switching topologies.

Technical Context

This device operates as a general-purpose PNP bipolar junction transistor with fixed emitter-base and collector-base junction structures optimized for linear amplification and saturated switching. Its −60 V V_CEO and −80 V V_CBO ratings support use in negative-rail signal conditioning and low-voltage DC-DC control stages.

The KSA708YBU exhibits hFE = 120–240 under V_CE = −2 V and I_C = −50 mA conditions, and delivers V_CE(sat) ≤ 0.7 V at I_C = −500 mA / I_B = −50 mA, confirming suitability for medium-current switching where base drive efficiency and thermal margin are critical.

Key Specifications

Pinout & Package

Package: TO-92 3-lead plastic case (Case 135AN), Pb-free, through-hole mount. Dimensions: 4.825 mm × 4.76 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KSA708YBU, MPSA92 offers superior voltage tolerance but reduced DC gain control and lower power dissipation, while KSA992 provides higher gain and power at the cost of increased thermal demand in identical mounting conditions.

Availability

KSA708YBU is available at Aetrix Electronics and suitable for audio pre-amplification, relay driving, DC-DC feedback control, and LED current sinking requiring stable component supply and long-term industrial availability.

Supply support for KSA708YBU 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, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The KSA708YBU belongs to onsemi's general-purpose bipolar transistor product line, engineered for cost-sensitive, reliability-critical discrete analog functions in consumer and industrial electronics.

FAQ

What is the pin configuration of the KSA708YBU?

The KSA708YBU uses a TO-92 3-lead package with pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector. This configuration is confirmed in the official onsemi datasheet (Publication Order Number KSA708/D, Rev. 4) and matches the mechanical outline CASE 135AN. The marking "A708Y" appears on the device body adjacent to Pin 1.

Is the KSA708YBU RoHS-compliant and lead-free?

Yes, the KSA708YBU is explicitly marked as Pb-free in the onsemi ordering information table and packaged in TO-92 3 LF (Case 135AR) or standard TO-92 3 (Case 135AN) per JEDEC standards. It meets RoHS Directive 2011/65/EU requirements for restricted substances, including lead content below 0.1 wt%.

What is the maximum operating junction temperature for the KSA708YBU?

The KSA708YBU has a maximum junction temperature (T_J) of 150°C, as specified in the Absolute Maximum Ratings table of the official datasheet. This rating applies under continuous operation with appropriate PCB copper area and ambient conditions; derating is required above 25°C ambient per the thermal resistance curve.

Can the KSA708YBU replace the KSA708YTA or KSA708CYTA?

No - KSA708YTA and KSA708CYTA are discontinued per onsemi documentation (Note 1, Ordering Information section). The KSA708YBU remains the active, Pb-free, bulk-packaged version. While electrically identical, KSA708YBU is the only currently orderable variant with guaranteed supply and full technical support.

What is the typical current gain (hFE) of the KSA708YBU at low collector current?

The KSA708YBU exhibits hFE = 120–240 when tested at V_CE = −2 V and I_C = −50 mA, per the Electrical Characteristics table. At lower currents (e.g., I_C = −10 mA), hFE typically rises toward the upper end of this range, supporting stable biasing in low-power amplifier stages using the KSA708YBU.