Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

onsemi BC636TA

Name: BC636TA
Brand: onsemi
SKU: BC636TA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BC636TA

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: BC636TA.pdf

Description:: TRANS PNP 45V 1A TO-92-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:5,388

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

BC636TA from onsemi is a PNP epitaxial silicon transistor designed for medium-power switching and linear amplification, with −45 V V_CEO, −1 A continuous collector current, and 100 MHz f_T; it serves as a complement to BC635 in push-pull output stages of audio amplifiers and relay drivers.

For engineers reviewing the BC636TA datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92-3 package compatibility, guaranteed h_FE ≥25 at IC = −5 mA, V_CE(sat) ≤ −0.5 V at IC = −500 mA/IB = −50 mA, and RoHS-compliant Pb-free construction.

Technical Context

This PNP bipolar junction transistor operates in common-emitter configuration with DC current gain (h_FE) ranging from 25 to 250 depending on collector current-25 at −500 mA, 40–250 at −150 mA, and 25 at −5 mA-enabling both saturated switching and analog amplification roles.

Its thermal resistance R_JA is 125 °C/W on standard FR-4 PCB (76 mm × 114 mm), supporting 1 W power dissipation at 25°C with 8 mW/°C derating above ambient, and it features −5 V V_EBO and −45 V V_CER/V_CES/V_CEO ratings for robust reverse-bias operation.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−45 V: Maximum safe collector-emitter voltage before breakdown under open-base condition.
I_C	−1 A: Continuous DC collector current rating defining maximum sustained load-handling capability.
f_T	100 MHz: Current-gain bandwidth product indicating usable frequency limit for small-signal amplification.
V_CE(sat)	−0.5 V @ I_C = −500 mA/I_B = −50 mA: Saturation voltage confirming low conduction loss in switching applications.
h_FE	25–250: DC current gain range across operating currents, enabling design flexibility for biasing in amplifier or switch modes.
P_D	1 W @ T_A = 25°C: Maximum power dissipation on standard PCB, requiring thermal derating above ambient temperature.

Pinout & Package

BC636TA is housed in a TO-92-3 plastic package (Case 135AR), with leads formed per standard leadform (4.83 mm × 4.76 mm). Pin 1 is Emitter, Pin 2 is Collector, Pin 3 is Base - verified per onsemi marking diagram and mechanical outline.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit terminal for PNP device	Connected to most positive rail in common-emitter switch; sets reference for base bias network.
2 (Collector)	Current entry terminal for PNP device	Drives load to ground in high-side switch configuration; requires proper heat sinking at >500 mA.
3 (Base)	Control input for minority-carrier injection	Receives current-limited drive (≤−100 mA) to achieve full saturation; sensitive to ESD due to −5 V V_EBO.

Key Features

Feature	Design Value
Pb-free, Halogen-free/BFR-free	Meets RoHS Directive 2011/65/EU without exemptions; eliminates hazardous substance handling in assembly and disposal.
Complementary pairing with BC635	Enables matched NPN/PNP push-pull output stages with symmetrical V_CEO, I_C, and f_T specs for reduced crossover distortion.
Guaranteed h_FE ≥25 at −500 mA	Ensures reliable saturation in high-current switching (e.g., solenoid drivers) without excessive base drive overhead.
100 MHz f_T	Supports audio-frequency amplification up to ~20 kHz with adequate gain margin and phase stability.

Applications

Audio Power Amplifier Output Stage	DC Motor Direction Control
Use Scenario: Used in Class-B or AB complementary output pairs driving 4–8 Ω speakers in portable audio systems. IC Role / Device Role / Timing Role: PNP switch/amplifier providing current sink capability during negative half-cycle of audio waveform. Use Value: Delivers −1 A peak current with <−0.5 V saturation drop, minimizing heat generation and preserving battery life.	Use Scenario: Integrated into H-bridge driver circuits controlling bidirectional rotation of brushed DC motors in robotics and actuators. IC Role / Device Role / Timing Role: High-side PNP switch enabling motor connection to V_CC when activated, paired with NPN low-side switches. Use Value: −45 V V_CEO withstands inductive kickback; TO-92 package allows compact layout in space-constrained motor control PCBs.
Relay Driver Circuit	Linear Voltage Regulator Pass Element
Use Scenario: Drives coil of 12 V/500 mA electromagnetic relays in industrial PLC I/O modules. IC Role / Device Role / Timing Role: Saturated switch turning relay ON/OFF via base current control; complements BC635 for dual-coil or latching relay logic. Use Value: −1 A I_C rating exceeds typical relay coil current; −0.5 V V_CE(sat) reduces power loss and self-heating during extended ON states.	Use Scenario: Functions as series pass transistor in adjustable linear regulators delivering up to 800 mA output current. IC Role / Device Role / Timing Role: Controlled conduction element regulating output voltage by dissipating excess input-output differential as heat. Use Value: 1 W power rating supports 10 V dropout at 100 mA; h_FE stability across temperature ensures consistent regulation accuracy.

Audio Power Amplifier Output Stage

DC Motor Direction Control

Use Scenario: Used in Class-B or AB complementary output pairs driving 4–8 Ω speakers in portable audio systems.

IC Role / Device Role / Timing Role: PNP switch/amplifier providing current sink capability during negative half-cycle of audio waveform.

Use Value: Delivers −1 A peak current with <−0.5 V saturation drop, minimizing heat generation and preserving battery life.

Use Scenario: Integrated into H-bridge driver circuits controlling bidirectional rotation of brushed DC motors in robotics and actuators.

IC Role / Device Role / Timing Role: High-side PNP switch enabling motor connection to V_CC when activated, paired with NPN low-side switches.

Use Value: −45 V V_CEO withstands inductive kickback; TO-92 package allows compact layout in space-constrained motor control PCBs.

Relay Driver Circuit

Linear Voltage Regulator Pass Element

Use Scenario: Drives coil of 12 V/500 mA electromagnetic relays in industrial PLC I/O modules.

IC Role / Device Role / Timing Role: Saturated switch turning relay ON/OFF via base current control; complements BC635 for dual-coil or latching relay logic.

Use Value: −1 A I_C rating exceeds typical relay coil current; −0.5 V V_CE(sat) reduces power loss and self-heating during extended ON states.

Use Scenario: Functions as series pass transistor in adjustable linear regulators delivering up to 800 mA output current.

IC Role / Device Role / Timing Role: Controlled conduction element regulating output voltage by dissipating excess input-output differential as heat.

Use Value: 1 W power rating supports 10 V dropout at 100 mA; h_FE stability across temperature ensures consistent regulation accuracy.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC638TA	Higher V_CEO (−60 V vs. −45 V); otherwise identical h_FE, f_T, and package.	Suitable where higher voltage margin is required (e.g., 24 V industrial systems with transients).	Select BC638TA if system supply exceeds 30 V or transient immunity >45 V is mandated.
MPSA92	Same V_CEO (−300 V), but lower h_FE (25–100), higher V_CE(sat) (−0.75 V), and TO-92 package with different pinout (E-C-B).	Better for high-voltage switching (e.g., flyback snubbers), less suitable for low-loss amplification.	Choose MPSA92 only when >100 V blocking is essential; verify pinout rework and gain margin in circuit.

Compared with BC636TA, BC638TA offers enhanced voltage headroom without sacrificing gain or speed, while MPSA92 trades off saturation performance and pin compatibility for extreme voltage capability-neither is pin-compatible, requiring layout review for substitution.

Availability

BC636TA is available at Aetrix Electronics and suitable for audio amplifier output stages, relay drivers, DC motor direction control, and linear regulator pass elements requiring stable component supply and RoHS-compliant manufacturing.

Supply support for BC636TA 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 electronics, delivering discrete, analog, logic, and custom devices for automotive, industrial, cloud, and IoT markets.

The BC636TA belongs to onsemi's general-purpose bipolar transistor family, engineered for cost-sensitive, medium-power linear and switching applications where reliability, thermal stability, and RoHS compliance are mandatory.

FAQ

What is the maximum collector-emitter voltage rating for BC636TA?

The BC636TA has a guaranteed V_CEO rating of −45 V at T_A = 25°C with open base. This applies identically to V_CES and V_CER per onsemi's datasheet, making BC636TA suitable for 30 V rail applications with safety margin. Exceeding this voltage risks avalanche breakdown and permanent damage.

Is BC636TA pin-compatible with BC635?

No, BC636TA is not pin-compatible with BC635. While both are TO-92-3 packaged transistors and functionally complementary (PNP vs. NPN), their pinouts differ: BC636TA uses E-C-B order (Pin 1=Emitter, Pin 2=Collector, Pin 3=Base), whereas BC635 uses E-B-C. Direct replacement requires PCB layout modification.

What is the typical DC current gain (h_FE) of BC636TA at 500 mA collector current?

Per the onsemi BC636/D datasheet, BC636TA exhibits h_FE ≥25 at V_CE = −2 V and I_C = −500 mA. This minimum gain ensures predictable saturation behavior in high-current switching applications such as relay or solenoid drivers using BC636TA.

Does BC636TA support surface-mount assembly?

No, BC636TA is through-hole only. It uses the TO-92-3 package (Case 135AR) with bent leads for axial insertion, and no SMT variant (e.g., SOT-23 or SC-70) is offered by onsemi for this part number. Reflow or wave soldering is not applicable; hand or automated through-hole placement is required.

What thermal derating applies to BC636TA above 25°C ambient?

BC636TA has a power dissipation derating factor of 8 mW/°C above 25°C ambient, based on its R_JA = 125 °C/W on a standard FR-4 PCB (76 mm × 114 mm). At 75°C ambient, its usable power drops to 0.6 W, requiring careful thermal design in enclosed or high-temperature environments where BC636TA operates continuously.

BC636TA Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Packaging:: Cut Tape (CT)

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 1 A

Voltage - Collector Emitter Breakdown (Max):: 45 V

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

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 40 @ 150mA, 2V

Power - Max:: 1 W

Frequency - Transition:: 100MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

BC636TA FAQ

1.How can I place an order for BC636TA through Aetrix?

Please submit a Request for Quotation (RFQ) for BC636TA 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 BC636TA reliable?

The price and inventory of BC636TA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC636TA is usually 5 days.

3.What payment methods are accepted for BC636TA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC636TA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC636TA?

BC636TA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC636TA 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 BC636TA?

For technical support, including BC636TA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC636TA requirements.

6.How does Aetrix verify that BC636TA is sourced from the original manufacturer or authorized distributors?

All BC636TA 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 BC636TA meets industry standards.

7.What is the process for return or replacement of BC636TA?

All BC636TA units undergo pre-shipment inspection (PSI). If there is an issue with BC636TA, 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 BC636TA part is unused and in its original packaging.

Return procedure for BC636TA:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-10 Schmitt Trigger Explained: Hysteresis, Circuits, Inverters and Applications

Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…