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 2SB1205S-TL-E

Name: 2SB1205S-TL-E
Brand: onsemi
SKU: 2SB1205S-TL-E
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 2SB1205S-TL-E

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: 2SB1205S-TL-E.pdf

Description:: TRANS PNP 20V 5A TP-FA

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:659

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

Product details

Overview

2SB1205S-TL-E from onsemi is a PNP bipolar junction transistor in TP-FA (TO-252) package, rated for −20 V V_CEO, −5 A I_C, and −250 mV typical V_CE(sat) at −3 A/−60 mA drive. It delivers fast switching (t_on = 40 ns, t_f = 10 ns) and high DC current gain (h_FE = 100–400), optimized for relay and lamp driver circuits in industrial control modules.

For engineers reviewing the 2SB1205S-TL-E datasheet, pinout, applications, or equivalent options, key selection criteria include verified −250 mV saturation voltage at −3 A, TO-252 thermal performance (10 W at T_c = 25°C), JEDEC SC-63 compliance, and rank-specific h_FE binning (S-rank: 140–280).

Technical Context

This PNP transistor uses FBET and MBIT processes to achieve low V_CE(sat) and fast switching-critical for high-efficiency DC load switching. Its dual-collector TP-FA structure supports high-current conduction while maintaining thermal stability under pulsed loads up to −8 A (I_CP).

The device operates across −55°C to +150°C junction temperature range with guaranteed breakdown ratings: −25 V V_(BR)CBO, −20 V V_(BR)CEO, and −5 V V_(BR)EBO. Gain-bandwidth product of 320 MHz enables stable operation in moderate-frequency switching applications without oscillation risk.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−20 V - Maximum safe collector-emitter voltage before avalanche; defines usable supply headroom in negative-rail switch designs.
I_C	−5 A - Continuous DC collector current; supports driving 5 A resistive or inductive loads without derating at T_c ≤ 25°C.
V_CE(sat)	−250 mV (typ) at −3 A/−60 mA - Low conduction loss reduces heat generation in high-duty-cycle lamp/relay drivers.
h_FE	140–280 (S-rank) - Tight DC current gain bin ensures predictable base drive requirements across production lots.
f_T	320 MHz - Sufficient bandwidth for clean switching edges in <100 kHz PWM-controlled loads.
t_f	10 ns - Fast fall time minimizes switching transition losses and EMI in compact PCB layouts.
P_C (T_c=25°C)	10 W - High power dissipation capability when mounted on heatsink; enables high-current operation without forced cooling.

Pinout & Package

Package: TP-FA (JEDEC TO-252, JEITA SC-63), surface-mount, 4-terminal configuration with dual collectors for enhanced current handling and thermal path optimization.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control input requiring −60 mA for full saturation at −3 A; compatible with standard logic-level drive via series resistor.
2	Collector	Main high-current output terminal; electrically tied to Pin 4 for parallel conduction and improved thermal spreading.
3	Emitter	Common return path for load current; connected to system ground or negative rail in high-side switch configurations.
4	Collector	Second collector terminal bonded internally to Pin 2; reduces effective R_DS(on)-like resistance and improves current sharing.

Key Features

Feature	Design Value
Low V_CE(sat)	−250 mV typ at −3 A ensures <0.75 W conduction loss, reducing thermal stress in enclosed industrial enclosures.
Fast switching	40 ns t_on/10 ns t_f enables efficient 50–100 kHz PWM dimming of LED arrays without audible noise or excessive gate drive complexity.
S-rank h_FE binning	140–280 h_FE guarantees consistent base current design across batches-eliminates need for recalculating R_B per lot.
Dual-collector TP-FA	Parallel collector terminals lower effective saturation resistance and improve thermal coupling to PCB copper pour for passive cooling.

Applications

Lamp Driver	Relay Driver
Use Scenario: Driving 12 V incandescent or halogen lamps in automotive interior lighting or industrial panel indicators. IC Role / Device Role / Timing Role: High-current PNP switch controlling lamp anode connection to positive rail; handles inrush currents up to −5 A. Use Value: −250 mV V_CE(sat) limits lamp voltage drop to <3% at full brightness, preserving luminous output and color consistency.	Use Scenario: Activating 24 VDC industrial relays with coil resistance ≤ 48 Ω in PLC I/O modules. IC Role / Device Role / Timing Role: Low-impedance emitter-follower switch sourcing relay coil current; withstands 10× inductive kickback energy. Use Value: 10 ns fall time suppresses voltage spikes >100 V/μs, reducing snubber component count and board space.
Voltage Regulator Pass Element	Flash Circuit Switch
Use Scenario: Series pass transistor in linear regulators supplying −5 V/2 A to analog sensor front-ends. IC Role / Device Role / Timing Role: Adjustable current source operating in active region; dissipates up to 10 W with external heatsink. Use Value: 150°C T_j rating and 10 W P_C allow sustained operation under worst-case dropout conditions without thermal shutdown.	Use Scenario: High-current discharge switch for xenon flash capacitors (300 V, 100 μF) in legacy camera modules. IC Role / Device Role / Timing Role: Fast-turn-off switch interrupting capacitor discharge path to terminate flash pulse precisely. Use Value: 320 MHz f_T ensures stable turn-off behavior even with high dV/dt transients (>500 V/μs) during flash termination.

Lamp Driver

Relay Driver

Use Scenario: Driving 12 V incandescent or halogen lamps in automotive interior lighting or industrial panel indicators.

IC Role / Device Role / Timing Role: High-current PNP switch controlling lamp anode connection to positive rail; handles inrush currents up to −5 A.

Use Value: −250 mV V_CE(sat) limits lamp voltage drop to <3% at full brightness, preserving luminous output and color consistency.

Use Scenario: Activating 24 VDC industrial relays with coil resistance ≤ 48 Ω in PLC I/O modules.

IC Role / Device Role / Timing Role: Low-impedance emitter-follower switch sourcing relay coil current; withstands 10× inductive kickback energy.

Use Value: 10 ns fall time suppresses voltage spikes >100 V/μs, reducing snubber component count and board space.

Voltage Regulator Pass Element

Flash Circuit Switch

Use Scenario: Series pass transistor in linear regulators supplying −5 V/2 A to analog sensor front-ends.

IC Role / Device Role / Timing Role: Adjustable current source operating in active region; dissipates up to 10 W with external heatsink.

Use Value: 150°C T_j rating and 10 W P_C allow sustained operation under worst-case dropout conditions without thermal shutdown.

Use Scenario: High-current discharge switch for xenon flash capacitors (300 V, 100 μF) in legacy camera modules.

IC Role / Device Role / Timing Role: Fast-turn-off switch interrupting capacitor discharge path to terminate flash pulse precisely.

Use Value: 320 MHz f_T ensures stable turn-off behavior even with high dV/dt transients (>500 V/μs) during flash termination.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SB1205T-TL-E	Same TP-FA package and electrical specs, but T-rank h_FE = 200–400 (vs. S-rank 140–280); higher minimum gain.	Better suited for low-base-drive designs where precise current amplification is critical, e.g., feedback loops in regulated supplies.	Select 2SB1205T-TL-E only if circuit requires guaranteed h_FE ≥ 200 at −4 A; otherwise S-rank offers tighter tolerance for cost-sensitive volume production.
MJD2955G	TO-252 PNP, −60 V V_CEO, −10 A I_C, −1.1 V V_CE(sat) at −5 A - higher voltage rating but significantly higher saturation voltage.	Preferred in 48 V telecom systems where breakdown margin is prioritized over conduction loss; unsuitable for low-voltage, high-efficiency lamp drivers.	Choose MJD2955G only when V_CEO > −40 V is mandatory; 2SB1205S-TL-E remains superior for −20 V systems demanding minimal power loss.

Compared with 2SB1205T-TL-E and MJD2955G, the 2SB1205S-TL-E provides optimal balance of low V_CE(sat), tight h_FE binning, and TO-252 thermal performance for −20 V, −5 A industrial switching-making it the preferred choice where efficiency, predictability, and footprint are jointly constrained.

Availability

2SB1205S-TL-E is available at Aetrix Electronics and suitable for lamp drivers, relay drivers, and voltage regulator pass elements requiring stable component supply, RoHS-compliant packaging, and JEDEC-qualified TO-252 form factor.

Supply support for 2SB1205S-TL-E 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 2SB1205 series belongs to onsemi's general-purpose bipolar transistor portfolio, engineered specifically for high-reliability DC switching in space-constrained industrial controls and power management subsystems.

FAQ

What is the maximum continuous collector current rating for the 2SB1205S-TL-E?

The 2SB1205S-TL-E is rated for −5 A continuous collector current (I_C) at T_c = 25°C. Derating is required above this case temperature; the device supports up to −8 A in pulsed operation (I_CP). This rating is validated per the Absolute Maximum Ratings table in the official onsemi datasheet No. 2114, ensuring reliable conduction in relay and lamp driver applications without thermal runaway.

Does the 2SB1205S-TL-E have a built-in flyback diode for inductive load protection?

No, the 2SB1205S-TL-E does not integrate a flyback diode. It is a discrete PNP bipolar transistor requiring external clamping-typically a Schottky diode from emitter to collector-to suppress inductive kickback when switching relays or solenoids. The device's −20 V V_CEO rating means external protection must limit reverse voltage to below this threshold to prevent breakdown during turn-off.

What does the 'S' in 2SB1205S-TL-E signify?

The 'S' in 2SB1205S-TL-E denotes the h_FE gain rank: S-rank specifies a DC current gain range of 140–280 at V_CE = −2 V and I_C = −500 mA. This binning ensures consistent base drive requirements across production lots of the 2SB1205S-TL-E, distinguishing it from the T-rank variant (200–400) and enabling robust, low-risk design without post-production gain screening.

Can the 2SB1205S-TL-E be used in linear regulator applications?

Yes, the 2SB1205S-TL-E is suitable for linear regulator pass element use due to its 10 W collector dissipation at T_c = 25°C, −20 V V_CEO, and stable h_FE across temperature. When mounted on an appropriate heatsink, the 2SB1205S-TL-E regulates −5 V outputs at up to −2 A with minimal dropout-leveraging its low −250 mV V_CE(sat) to maximize efficiency and minimize thermal load.

What is the lead-free status and packaging format of the 2SB1205S-TL-E?

The 2SB1205S-TL-E is Pb-free and RoHS-compliant, shipped in 700-piece embossed carrier tape reels (TP-FA package). The 'TL' suffix explicitly indicates tape-and-reel packaging per onsemi's ordering nomenclature, and the device meets JESD97 and JEDEC Level 3 moisture sensitivity standards-ensuring compatibility with standard SMT reflow profiles without preconditioning.

2SB1205S-TL-E Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 5 A

Voltage - Collector Emitter Breakdown (Max):: 20 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 60mA, 3A

Current - Collector Cutoff (Max):: 500nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 140 @ 500mA, 2V

Power - Max:: 1 W

Frequency - Transition:: 320MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: TP-FA

2SB1205S-TL-E FAQ

1.How can I place an order for 2SB1205S-TL-E through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SB1205S-TL-E 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 2SB1205S-TL-E reliable?

The price and inventory of 2SB1205S-TL-E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SB1205S-TL-E is usually 5 days.

3.What payment methods are accepted for 2SB1205S-TL-E?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SB1205S-TL-E transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SB1205S-TL-E?

2SB1205S-TL-E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SB1205S-TL-E 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 2SB1205S-TL-E?

For technical support, including 2SB1205S-TL-E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SB1205S-TL-E requirements.

6.How does Aetrix verify that 2SB1205S-TL-E is sourced from the original manufacturer or authorized distributors?

All 2SB1205S-TL-E 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 2SB1205S-TL-E meets industry standards.

7.What is the process for return or replacement of 2SB1205S-TL-E?

All 2SB1205S-TL-E units undergo pre-shipment inspection (PSI). If there is an issue with 2SB1205S-TL-E, 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 2SB1205S-TL-E part is unused and in its original packaging.

Return procedure for 2SB1205S-TL-E:

1.Submit a request within 90 days.

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

Tech Hub

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…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…