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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi 2SA1770S-AN

Name: 2SA1770S-AN
Brand: onsemi
SKU: 2SA1770S-AN
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SA1770S-AN

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: SC-71

Datasheet:: 2SA1770S-AN.pdf

Description:: TRANS PNP 160V 1.5A 3-NMP

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Product details

Overview

2SA1770S-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, f_T = 120 MHz, and SC-71 (NMP) surface-mount package. It is used in power supply control circuits requiring robust breakdown voltage and low saturation voltage.

For engineers reviewing the 2SA1770S-AN datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, confirmed –160 V V_CEO, measured –450 mV V_CE(sat) under specified drive conditions, documented h_FE range of 140–280 at I_C = –100 mA, and SC-71 mechanical compatibility with automated SMT assembly.

Technical Context

The 2SA1770S-AN employs MBIT process technology to achieve high breakdown voltage and large current handling while maintaining fast switching performance. Its electrical behavior is defined by V_(BR)CBO = –180 V, V_(BR)CEO = –160 V, and V_(BR)EBO = –6 V - all tested at specified leakage currents - supporting reliable operation in high-side switch and linear regulator driver roles.

Switching timing is characterized with t_on = 40 ns, t_stg = 1.2 μs, and t_f = 80 ns under V_CC = –100 V, I_C = –0.7 A, and 20 μs pulse width. The device exhibits C_ob = 14 pF at V_CB = –10 V and f = 1 MHz, enabling stable high-frequency gain response up to its 120 MHz f_T.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	–160 V - supports high-side switching in 100–150 V DC bus applications without avalanche stress
I_C	–1.5 A continuous - enables direct drive of medium-power loads such as relay coils or LED strings
V_CE(sat)	–450 mV at I_C = –500 mA / I_B = –50 mA - minimizes conduction loss and thermal rise in saturated-switch mode
f_T	120 MHz - ensures usable gain in audio-frequency amplification and fast PWM-driven switching
h_FE	140–280 at V_CE = –5 V, I_C = –100 mA - provides predictable base drive requirements for stable bias design
P_C	1 W at T_A = 25°C - defines maximum steady-state power dissipation before thermal derating applies
C_ob	14 pF at V_CB = –10 V, f = 1 MHz - limits Miller capacitance impact on turn-off speed in inductive load switching

Pinout & Package

Package: SC-71 (JEITA/ JEDEC), also designated NMP(Taping); compact 3-pin surface-mount outline with 2.54 mm lead pitch, 0.275 g mass, and Pb-free finish.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Current exit terminal for PNP operation; connects to most positive rail in high-side switch configuration
2	Collector	Current entry terminal; ties to load return path or ground-referenced node in common-emitter topology
3	Base	Control input; requires negative bias relative to emitter to forward-bias base-emitter junction and enable conduction

Key Features

Feature	Design Value
MBIT process technology	Enables simultaneous optimization of breakdown voltage, current capacity, and switching speed in a single PNP die
Low V_CE(sat)	–450 mV at rated I_C/I_B reduces power loss and simplifies heatsinking in 1 W-class switching nodes
High V_CEO	–160 V rating allows direct use in industrial 120 V AC rectified supplies without series stacking or snubbing
SC-71 package	Standardized JEITA/ JEDEC footprint ensures compatibility with existing pick-and-place tooling and reflow profiles
Rank S h_FE binning	Guaranteed 140–280 h_FE at I_C = –100 mA enables consistent base resistor selection across production lots

Applications

DC-DC Converter High-Side Switch	Linear Regulator Pass Transistor
Use Scenario: Used as the upper switch in non-synchronous buck converters operating from 100–150 V DC input rails. IC Role / Device Role / Timing Role: PNP BJT configured in common-emitter mode, driven by complementary logic-level signal with base current limiting. Use Value: –160 V V_CEO and –450 mV V_CE(sat) allow efficient switching with minimal voltage headroom loss and reduced thermal overhead.	Use Scenario: Functions as the series pass element in adjustable negative-output linear regulators delivering up to –1.2 A. IC Role / Device Role / Timing Role: Operates in active region with feedback-controlled base bias to regulate output voltage against load and line variations. Use Value: Stable h_FE range (140–280) and low V_CE(sat) ensure predictable dropout voltage and thermal stability under full-load conditions.
Relay Driver Circuit	LED String Current Sink
Use Scenario: Drives 24–48 V DC coil relays in industrial PLC output modules requiring galvanically isolated switching. IC Role / Device Role / Timing Role: PNP switch placed between positive rail and relay coil, turned on by microcontroller GPIO pulled low via base resistor. Use Value: –1.5 A I_C rating accommodates relay inrush currents up to 2.5 A (pulse), while –180 V V_CBO prevents breakdown during coil flyback transients.	Use Scenario: Sinks current from multi-segment high-brightness LED strings in signage or backlighting systems powered from –48 V rails. IC Role / Device Role / Timing Role: Configured as constant-current sink with emitter-follower bias network and sense resistor feedback. Use Value: Low V_CE(sat) minimizes voltage drop across the transistor, preserving headroom for LED forward voltage and improving overall efficiency.

DC-DC Converter High-Side Switch

Linear Regulator Pass Transistor

Use Scenario: Used as the upper switch in non-synchronous buck converters operating from 100–150 V DC input rails.

IC Role / Device Role / Timing Role: PNP BJT configured in common-emitter mode, driven by complementary logic-level signal with base current limiting.

Use Value: –160 V V_CEO and –450 mV V_CE(sat) allow efficient switching with minimal voltage headroom loss and reduced thermal overhead.

Use Scenario: Functions as the series pass element in adjustable negative-output linear regulators delivering up to –1.2 A.

IC Role / Device Role / Timing Role: Operates in active region with feedback-controlled base bias to regulate output voltage against load and line variations.

Use Value: Stable h_FE range (140–280) and low V_CE(sat) ensure predictable dropout voltage and thermal stability under full-load conditions.

Relay Driver Circuit

LED String Current Sink

Use Scenario: Drives 24–48 V DC coil relays in industrial PLC output modules requiring galvanically isolated switching.

IC Role / Device Role / Timing Role: PNP switch placed between positive rail and relay coil, turned on by microcontroller GPIO pulled low via base resistor.

Use Value: –1.5 A I_C rating accommodates relay inrush currents up to 2.5 A (pulse), while –180 V V_CBO prevents breakdown during coil flyback transients.

Use Scenario: Sinks current from multi-segment high-brightness LED strings in signage or backlighting systems powered from –48 V rails.

IC Role / Device Role / Timing Role: Configured as constant-current sink with emitter-follower bias network and sense resistor feedback.

Use Value: Low V_CE(sat) minimizes voltage drop across the transistor, preserving headroom for LED forward voltage and improving overall efficiency.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SA1770T-AN	Same package and absolute ratings, but h_FE binned 200–400 at I_C = –100 mA	Higher gain enables lower base drive current; suitable where tighter h_FE tolerance is required	Select 2SA1770T-AN when designing for reduced base current consumption or improved consistency in feedback loops
MJD2955G	TO-252 package, V_CEO = –60 V, I_C = –12 A, V_CE(sat) = –1.8 V at I_C = –8 A	Higher current, lower voltage rating; incompatible for >–100 V applications due to V_CEO limit	Choose MJD2955G only for lower-voltage, higher-current switching where PCB layout allows DPAK footprint

Compared with 2SA1770T-AN, the 2SA1770S-AN offers lower and more tightly bounded h_FE, simplifying base bias design in fixed-resistor networks; versus MJD2955G, it trades current capacity for higher voltage capability and smaller SC-71 footprint - critical for space-constrained 100+ V DC designs.

Availability

2SA1770S-AN is available at Aetrix Electronics and suitable for DC-DC converter high-side switches, linear regulator pass elements, and relay driver circuits requiring stable component supply, consistent h_FE binning, and Pb-free compliance.

Supply support for 2SA1770S-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 focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.

The 2SA1770S-AN belongs to onsemi's general-purpose bipolar transistor product line, engineered specifically for high-voltage, medium-current switching and amplification in industrial power electronics and control systems.

FAQ

What is the polarity and transistor type of the 2SA1770S-AN?

The 2SA1770S-AN is a PNP bipolar junction transistor. Its part number prefix "2SA" follows Japanese Industrial Standard (JIS) designation, where "A" indicates PNP small-signal or switching transistor. Confirmed electrical behavior - including negative voltage ratings (V_CEO = –160 V), negative current ratings (I_C = –1.5 A), and emitter-base forward bias requiring V_EB > 0 - validates its PNP structure. This polarity is essential for high-side switching configurations.

What does the "S" suffix in 2SA1770S-AN signify?

The "S" in 2SA1770S-AN denotes the h_FE gain rank bin: devices marked "S" are tested and guaranteed to exhibit DC current gain between 140 and 280 at V_CE = –5 V and I_C = –100 mA. This binning enables predictable base drive design and consistent performance across production lots. The alternative "T" variant (2SA1770T-AN) is binned 200–400 for higher-gain applications.

Is the 2SA1770S-AN RoHS compliant and Pb-free?

Yes, the 2SA1770S-AN is explicitly marked "Pb Free" in the ordering information and conforms to RoHS Directive 2011/65/EU. Its NMP(Taping) packaging uses lead-free terminations and complies with JEDEC J-STD-020 moisture sensitivity level (MSL) requirements. The device is suitable for lead-free reflow soldering processes with peak temperatures up to 260°C.

What is the thermal resistance junction-to-ambient (R_θJA) for the 2SA1770S-AN?

The datasheet does not specify R_θJA for the 2SA1770S-AN in isolation; however, the SC-71 (NMP) package has a typical R_θJA of 300°C/W on standard FR-4 PCB with no copper pour. Derating begins above T_A = 25°C per the PC–Ta curve: at 75°C ambient, maximum allowable power drops to ~0.5 W. For thermally demanding applications, use of thermal vias or local copper area is recommended to improve heat extraction.

Can the 2SA1770S-AN replace the 2SA1015 or 2SA933 in existing designs?

No - the 2SA1770S-AN is not a direct replacement for 2SA1015 (V_CEO = –50 V) or 2SA933 (V_CEO = –60 V). Its –160 V V_CEO and –1.5 A I_C rating target significantly higher-voltage applications. Substituting it into legacy low-voltage circuits risks over-specification, potential base drive mismatch due to higher h_FE, and unnecessary cost. Always verify voltage, current, gain, and package compatibility before substitution; the 2SA1770S-AN is intended for new 100+ V DC designs.

2SA1770S-AN Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SC-71

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 1.5 A

Voltage - Collector Emitter Breakdown (Max):: 160 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 50mA, 500mA

Current - Collector Cutoff (Max):: 1µA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 100mA, 5V

Power - Max:: 1 W

Frequency - Transition:: 120MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: 3-NMP

2SA1770S-AN FAQ

1.How can I place an order for 2SA1770S-AN through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SA1770S-AN on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 2SA1770S-AN reliable?

The price and inventory of 2SA1770S-AN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SA1770S-AN is usually 5 days.

3.What payment methods are accepted for 2SA1770S-AN?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SA1770S-AN transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SA1770S-AN?

2SA1770S-AN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SA1770S-AN order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 2SA1770S-AN?

For technical support, including 2SA1770S-AN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SA1770S-AN requirements.

6.How does Aetrix verify that 2SA1770S-AN is sourced from the original manufacturer or authorized distributors?

All 2SA1770S-AN products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 2SA1770S-AN meets industry standards.

7.What is the process for return or replacement of 2SA1770S-AN?

All 2SA1770S-AN units undergo pre-shipment inspection (PSI). If there is an issue with 2SA1770S-AN, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 2SA1770S-AN part is unused and in its original packaging.

Return procedure for 2SA1770S-AN:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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