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

onsemi MMBTA63

Name: MMBTA63
Brand: onsemi
SKU: MMBTA63
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMBTA63

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: MMBTA63.pdf

Description:: TRANS PNP DARL 30V 1.2A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Inventory:24,000

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Product details

Overview

MMBTA63 from Fairchild Semiconductor is a PNP Darlington transistor in SOT-23 package, rated for -30 V V_CEO, -1.2 A continuous collector current, and 350 mW power dissipation at 25°C. It delivers minimum DC current gain (h_FE) of 5,000 at -10 mA and -5 V, with V_CE(sat) ≤ -1.5 V at -100 mA/-0.1 mA drive-ideal for high-gain low-to-medium-power switching in industrial control interfaces.

For engineers reviewing the MMBTA63 datasheet, pinout, applications, or equivalent options, key selection criteria include verified Darlington architecture, SOT-23 thermal resistance (R_θJA = 357 °C/W), guaranteed h_FE ≥ 5,000 at low bias, and confirmed -30 V breakdown rating across temperature.

Technical Context

The MMBTA63 implements a monolithic PNP Darlington pair with integrated base-emitter resistor network absent-requiring external base drive. Its high h_FE enables microampere-level base current to switch >100 mA loads, reducing MCU GPIO burden in discrete logic-level interface circuits.

Thermal performance is defined for SOT-23 mounting on FR-4 PCB (36 mm × 18 mm × 1.5 mm) with ≥6 cm² collector pad; R_θJA de-rates at 2.8 mW/°C above 25°C, limiting usable ambient range under full load without heatsinking.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-30 V - Maximum safe collector-emitter voltage before avalanche conduction in open-base condition
I_C (cont.)	-1.2 A - Continuous DC collector current capability with derating above 25°C
P_D @ 25°C	350 mW - Total power dissipation limit on standard FR-4 board; defines max I²R + V_CEI_C operating envelope
h_FE min	5,000 @ -10 mA, -5 V - Ensures <10 µA base drive suffices for 10 mA load switching
V_CE(sat)	≤ -1.5 V @ -100 mA, -0.1 mA - Confirms low-loss saturation for efficient switching into resistive loads
f_T	125 MHz @ -10 mA, -5 V - Supports moderate-speed switching up to ~10–20 MHz with controlled rise/fall times

Pinout & Package

SOT-23 plastic surface-mount package with gull-wing leads; marked "2U". Thermal pad not present-collector lead serves as primary thermal path.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Emitter terminal of PNP Darlington pair	Connected to higher potential rail; current flows out of this pin during conduction
2 (Base)	Input control terminal	Receives negative-going drive signal relative to emitter to turn on device
3 (Collector)	Output current terminal	Connected to load; sinks current toward ground or lower-potential node when active

Key Features

Feature	Design Value
High DC current gain	h_FE ≥ 5,000 at -10 mA ensures minimal base drive overhead in microcontroller-driven switches
Guaranteed breakdown voltage	V_CEO = -30 V allows reliable operation in 24 V industrial bus interfaces with margin
Low saturation voltage	V_CE(sat) ≤ -1.5 V at -100 mA reduces power loss and self-heating in sustained on-state
SOT-23 footprint compatibility	Standard 3-pin SOT-23 layout enables drop-in replacement for other small-signal Darlingtons in space-constrained designs

Applications

Industrial Relay Drivers	Low-Voltage Logic-Level Shifters
Use Scenario: Driving 24 V DC relay coils from 3.3 V/5 V microcontroller GPIO pins with no external driver IC. IC Role / Device Role / Timing Role: High-gain PNP Darlington switch providing current amplification and level inversion. Use Value: Eliminates need for dual-transistor discrete stage; single MMBTA63 delivers >100 mA coil current with <10 µA base drive.	Use Scenario: Converting open-drain I²C or UART signals from 3.3 V domain to 5 V or 12 V bus levels. IC Role / Device Role / Timing Role: Active pull-up switch enabling bidirectional level translation without timing skew. Use Value: V_CE(sat) ≤ -1.5 V ensures low-voltage logic '0' remains below 0.4 V even at 10 mA sink current.
LED Array Current Sinks	Overcurrent Protection Enable Stages
Use Scenario: Controlling multi-segment LED displays or status indicators powered from 5–12 V rails. IC Role / Device Role / Timing Role: Low-side current sink switch with fast enough f_T (125 MHz) for PWM dimming up to 20 kHz. Use Value: h_FE ≥ 5,000 allows direct GPIO control without base resistor calculation errors affecting brightness consistency.	Use Scenario: Enabling/disabling power to downstream circuitry based on fault detection signals from supervisor ICs. IC Role / Device Role / Timing Role: High-reliability enable switch interfacing between fault logic and PMIC or LDO enable inputs. Use Value: -30 V V_CEO withstands transient coupling on enable lines; leakage <100 nA prevents false triggering.

Industrial Relay Drivers

Low-Voltage Logic-Level Shifters

Use Scenario: Driving 24 V DC relay coils from 3.3 V/5 V microcontroller GPIO pins with no external driver IC.

IC Role / Device Role / Timing Role: High-gain PNP Darlington switch providing current amplification and level inversion.

Use Value: Eliminates need for dual-transistor discrete stage; single MMBTA63 delivers >100 mA coil current with <10 µA base drive.

Use Scenario: Converting open-drain I²C or UART signals from 3.3 V domain to 5 V or 12 V bus levels.

IC Role / Device Role / Timing Role: Active pull-up switch enabling bidirectional level translation without timing skew.

Use Value: V_CE(sat) ≤ -1.5 V ensures low-voltage logic '0' remains below 0.4 V even at 10 mA sink current.

LED Array Current Sinks

Overcurrent Protection Enable Stages

Use Scenario: Controlling multi-segment LED displays or status indicators powered from 5–12 V rails.

IC Role / Device Role / Timing Role: Low-side current sink switch with fast enough f_T (125 MHz) for PWM dimming up to 20 kHz.

Use Value: h_FE ≥ 5,000 allows direct GPIO control without base resistor calculation errors affecting brightness consistency.

Use Scenario: Enabling/disabling power to downstream circuitry based on fault detection signals from supervisor ICs.

IC Role / Device Role / Timing Role: High-reliability enable switch interfacing between fault logic and PMIC or LDO enable inputs.

Use Value: -30 V V_CEO withstands transient coupling on enable lines; leakage <100 nA prevents false triggering.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT6427	V_CEO = -25 V, h_FE min = 2,000 @ -10 mA - lower breakdown and gain than MMBTA63	Not suitable for 24 V relay drivers requiring >25 V margin; acceptable only in ≤15 V systems	Select MMBT6427 only if board space and cost outweigh need for 30 V rating and 5× gain headroom
PN2907A	TO-92 package, V_CEO = -60 V, h_FE min = 100 @ -150 mA - higher voltage but much lower gain and larger footprint	Requires PCB redesign for through-hole mounting; insufficient h_FE for microampere-drive scenarios	Choose PN2907A only when legacy TO-92 compatibility or 60 V rating is mandatory and gain requirements are relaxed

Compared with MMBTA63, MMBT6427 offers smaller size but sacrifices 5 V breakdown margin and 2.5× DC gain; PN2907A provides superior voltage rating and ruggedness but demands through-hole assembly and cannot replace MMBTA63 in low-base-current applications.

Availability

MMBTA63 is available at Aetrix Electronics and suitable for industrial relay drivers, low-voltage logic-level shifters, LED array current sinks, and overcurrent protection enable stages requiring stable component supply and consistent parametric performance across production lots.

Supply support for MMBTA63 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

Fairchild Semiconductor was a U.S.-based analog and power semiconductor manufacturer acquired by ON Semiconductor in 2016; its legacy products remain widely deployed in industrial and automotive systems.

The MMBTA63 belongs to Fairchild's general-purpose discrete transistor family designed specifically for high-current-gain switching in compact SMT form factors where base drive efficiency and thermal manageability are critical.

FAQ

What is the maximum collector-emitter voltage rating for MMBTA63?

The MMBTA63 has a guaranteed collector-emitter breakdown voltage (V_CEO) of -30 V at I_C = -100 µA and I_B = 0. This rating applies across the full operating temperature range (-55°C to +150°C) and defines the absolute maximum reverse-biased voltage the device can block in open-base configuration. Exceeding -30 V risks avalanche conduction and permanent degradation of the MMBTA63.

Does MMBTA63 have an integrated base-emitter resistor?

No, the MMBTA63 is a bare PNP Darlington transistor without any integrated base-emitter resistor. It requires an external current-limiting resistor between the driving source and the base terminal to set appropriate base current. Unlike digital transistors (e.g., EMH series), the MMBTA63 offers full design flexibility for bias optimization but places responsibility for base drive design on the circuit engineer.

What is the thermal resistance junction-to-ambient for MMBTA63?

The MMBTA63 has a specified R_θJA of 357 °C/W when mounted on a standard FR-4 PCB (36 mm × 18 mm × 1.5 mm) with a minimum 6 cm² copper pad connected to the collector lead. This value assumes natural convection cooling only; forced airflow or additional copper area will improve thermal performance. The MMBTA63 must be derated at 2.8 mW/°C above 25°C ambient.

Can MMBTA63 be used as a direct replacement for MPSA63?

No, MMBTA63 is not a direct replacement for MPSA63 due to differing packages and thermal characteristics: MPSA63 uses TO-92 (R_θJA = 200 °C/W), while MMBTA63 uses SOT-23 (R_θJA = 357 °C/W). Though both share identical electrical specs, the MMBTA63 dissipates less power at the same ambient temperature and requires different PCB layout. Interchange requires verification of thermal margin and footprint adaptation.

What is the minimum DC current gain (h_FE) of MMBTA63 at -100 mA collector current?

The MMBTA63 guarantees h_FE ≥ 10,000 at I_C = -100 mA and V_CE = -5.0 V, per the official Fairchild datasheet Rev. A1. This exceptionally high gain enables sub-10 µA base currents to fully saturate the device at 100 mA load, making it especially valuable in ultra-low-power control applications where GPIO drive strength is limited.

MMBTA63 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Bulk

Product Status:: Active

Transistor Type:: PNP - Darlington

Current - Collector (Ic) (Max):: 1.2 A

Voltage - Collector Emitter Breakdown (Max):: 30 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 100µA, 100mA

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 10000 @ 100mA, 5V

Power - Max:: 350 mW

Frequency - Transition:: 125MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

MMBTA63 FAQ

1.How can I place an order for MMBTA63 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMBTA63 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 MMBTA63 reliable?

The price and inventory of MMBTA63 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBTA63 is usually 5 days.

3.What payment methods are accepted for MMBTA63?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBTA63 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMBTA63?

MMBTA63 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMBTA63 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 MMBTA63?

For technical support, including MMBTA63 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBTA63 requirements.

6.How does Aetrix verify that MMBTA63 is sourced from the original manufacturer or authorized distributors?

All MMBTA63 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 MMBTA63 meets industry standards.

7.What is the process for return or replacement of MMBTA63?

All MMBTA63 units undergo pre-shipment inspection (PSI). If there is an issue with MMBTA63, 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 MMBTA63 part is unused and in its original packaging.

Return procedure for MMBTA63:

1.Submit a request within 90 days.

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

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