onsemi 2SA1770T-AN

Overview

2SA1770T-AN from onsemi is a PNP bipolar junction transistor (BJT) designed for high-voltage switching applications, featuring V_CEO = −160 V, I_C = −1.5 A, V_CE(sat) = −450 mV at I_C = −500 mA / I_B = −50 mA, and f_T = 120 MHz. It employs MBIT process technology and is housed in SC-71 (NMP) package with 3-pin taping configuration.

For engineers reviewing the 2SA1770T-AN datasheet, pinout, applications, or equivalent options, this device serves as a high-breakdown-voltage, low-saturation-voltage PNP switch in industrial power supplies, relay drivers, and motor control circuits where robust DC current handling and fast switching are required.

Technical Context

The 2SA1770T-AN operates as a single PNP BJT with verified h_FE range of 200–400 at I_C = −100 mA and V_CE = −5 V, supporting precise current amplification in linear and saturated switching modes. Its rated T_j = 150 °C and T_stg = −55 to +150 °C enable reliable operation in extended ambient environments.

Electrical behavior is characterized by low V_CE(sat) (−450 mV max), fast switching times (t_on = 40 ns, t_f = 80 ns), and high f_T (120 MHz), confirming suitability for medium-frequency switching up to several tens of MHz under controlled bias conditions.

Key Specifications

Pinout & Package

Package: SC-71 (JEITA/JEDEC standard), also designated NMP(Taping); compact surface-mount plastic package with 3-terminal leadframe, 0.275 g mass, and 2.54 mm pin pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP high-voltage switching applications.

Compared with 2SA1770S-AN and MJD2955G, the 2SA1770T-AN delivers optimal balance of high-voltage capability, fast switching, and surface-mount compatibility-making it preferred for space-constrained, medium-power switching where gain consistency and thermal efficiency are critical.

Availability

2SA1770T-AN is available at Aetrix Electronics and suitable for industrial power supplies, relay drivers, and DC motor control circuits requiring stable component supply and long-term manufacturing continuity.

Supply support for 2SA1770T-AN 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 management, analog, sensor, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The 2SA1770T-AN belongs to onsemi's general-purpose bipolar transistor product line, engineered specifically for high-reliability, high-voltage switching in industrial automation and power conversion systems where ruggedness and parametric consistency are essential.

FAQ

What is the maximum collector-emitter voltage rating for the 2SA1770T-AN?

The 2SA1770T-AN has a guaranteed V_CEO rating of −160 V at T_a = 25 °C, meaning it can safely block up to 160 V in reverse-biased collector-emitter configuration without breakdown. This rating is validated per JEDEC JESD78 and applies under pulsed and DC conditions within specified thermal limits. The 2SA1770T-AN must not be operated beyond this voltage to prevent permanent damage.

How does the 2SA1770T-AN differ from the 2SA1770S-AN variant?

The 2SA1770T-AN and 2SA1770S-AN share identical package, pinout, absolute maximum ratings, and electrical characteristics except for DC current gain (h_FE). The 2SA1770T-AN is binned to h_FE = 200–400 at I_C = −100 mA, while the 2SA1770S-AN is binned to h_FE = 140–280. Both are manufactured using the same MBIT process and SC-71 package, and both carry Pb-free compliance per RoHS.

Is the 2SA1770T-AN suitable for use in Class D audio amplifier output stages?

The 2SA1770T-AN is not recommended for Class D audio amplifier output stages due to its relatively high V_CE(sat) (−450 mV) and limited safe operating area at high frequency and high current. While its f_T = 120 MHz supports medium-speed switching, the 2SA1770T-AN lacks the SOA robustness and low R_DS(on)-equivalent conduction loss required for efficient audio PWM output. Dedicated audio BJTs or MOSFETs are preferred.

What is the thermal resistance junction-to-ambient (R_θJA) for the 2SA1770T-AN in its NMP package?

The 2SA1770T-AN in SC-71 (NMP) package has a typical R_θJA of 200 °C/W when mounted on a standard FR-4 PCB with 1 cm² copper pad. This value is derived from its 1 W power dissipation rating at T_a = 25 °C and measured junction temperature limit of 150 °C. No thermal pad or heatsink is integrated into the NMP package, so layout-level copper area directly impacts thermal performance.

Does the 2SA1770T-AN require a base resistor for safe operation in switching mode?

Yes, the 2SA1770T-AN requires an external base resistor to limit I_B and ensure proper saturation without exceeding its base-emitter junction rating. For example, driving the 2SA1770T-AN with I_C = −500 mA and minimum h_FE = 200 requires I_B ≥ −2.5 mA. With V_BE(sat) ≈ −0.85 V and a 5 V logic source, a 1.6 kΩ resistor provides appropriate bias. Omitting this resistor risks thermal runaway or secondary breakdown.