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

onsemi SMMBTA64LT1G

Name: SMMBTA64LT1G
Brand: onsemi
SKU: SMMBTA64LT1G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SMMBTA64LT1G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: SMMBTA64LT1G.pdf

Description:: TRANS PNP DARL 30V 0.5A SOT23-3

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Product details

Overview

SMMBTA64LT1G from onsemi is a PNP silicon Darlington transistor in SOT-23 package, rated for −30 V_CEO, −500 mA continuous collector current, and 20,000 minimum DC current gain (h_FE) at −100 mA / −5 V. It delivers low saturation voltage (V_CE(sat) ≤ −1.5 V) and high-frequency response (f_T = 125 MHz), enabling use in automotive load switching and industrial relay drivers.

For engineers reviewing the SMMBTA64LT1G datasheet, pinout, applications, or equivalent options, key selection criteria include its AEC-Q101 qualification, Pb-free RoHS-compliant construction, −10 V_EBO rating, thermal resistance of 417 °C/W on alumina substrate, and verified Darlington configuration with base-emitter on voltage up to −2.0 V.

Technical Context

The SMMBTA64LT1G implements a monolithic PNP Darlington pair with integrated base-emitter resistor network absent - requiring external base drive control. Its high h_FE (10,000–20,000) enables microamp-level base current to switch 100 mA loads, while V_CE(sat) ≤ −1.5 V at I_C/I_B = 1000 ensures minimal conduction loss in low-voltage logic-driven circuits.

Thermal performance is defined for two board conditions: 300 mW dissipation on 0.4 × 0.3 in. alumina (R_JA = 417 °C/W), and 225 mW on FR-5 (R_JA = 556 °C/W). Junction temperature range spans −55 °C to +150 °C, supporting under-hood automotive environments per AEC-Q101 stress testing.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−30 V - Maximum blocking voltage between collector and emitter before breakdown; defines safe operating voltage margin in 24 V automotive systems.
I_C (cont.)	−500 mA - Continuous collector current capability; supports driving small relays, LEDs, or solenoids without heatsinking.
h_FE	10,000–20,000 - High DC current gain at −100 mA/−5 V; allows low-base-current control from MCU GPIOs or logic buffers.
V_CE(sat)	≤ −1.5 V - Low saturation voltage at −100 mA/−0.1 mA base drive; minimizes power loss and self-heating in switching applications.
f_T	125 MHz - Current-gain bandwidth product at −10 mA/−5 V; supports stable operation up to ~10 MHz switching with adequate phase margin.
V_BE(on)	≤ −2.0 V - Base-emitter turn-on voltage at −100 mA; informs required driver voltage headroom in series-base configurations.
R_JA (alumina)	417 °C/W - Thermal resistance junction-to-ambient on 0.4 × 0.3 in. 99.5% alumina; enables 300 mW dissipation at +25 °C ambient.

Pinout & Package

SOT-23 (TO-236) surface-mount plastic package, 2.90 × 1.30 × 1.00 mm body size, 1.90 mm lead pitch. Moisture sensitivity level (MSL) 1, Pb-free and RoHS compliant.

Pin/Terminal	Circuit Role	Design Meaning
1 - Base	Control input node	Receives base current to activate Darlington pair; requires external current-limiting resistor when driven from 3.3 V/5 V logic.
2 - Emitter	PNP emitter terminal	Connected to higher potential rail (e.g., +12 V); serves as common reference for load return path.
3 - Collector	Output current sink	Connects to load (e.g., relay coil or LED anode); current flows from emitter to collector when device is on.

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive applications including engine control modules and body electronics per stress test requirements.
Pb-free, Halogen-free/BFR-free	Complies with RoHS Directive 2011/65/EU and JEDEC JS709E; eliminates hazardous substances in final assembly.
Darlington architecture	Two cascaded PNP transistors provide >10× higher h_FE than single-stage devices, reducing base drive burden.
High f_T (125 MHz)	Enables clean switching waveforms up to ~10 MHz with controlled rise/fall times and minimal overshoot.
Wide T_J range (−55 to +150 °C)	Supports operation in under-dash, under-hood, and industrial control enclosures without derating below −40 °C.

Applications

Automotive Door Module	Industrial PLC Output Stage
Use Scenario: Driving 12 V window lift motor relays and door lock solenoids in centralized body control units. IC Role / Device Role / Timing Role: High-gain PNP Darlington switch controlling inductive loads via MCU GPIO with <100 µA base current. Use Value: Eliminates need for discrete driver stages; −30 V_CEO and −500 mA rating ensure robustness against load dump transients and coil flyback.	Use Scenario: Isolating and amplifying digital outputs from PLC CPU to 24 V DC field actuators (valves, indicators). IC Role / Device Role / Timing Role: Level-shifting and current-boosting interface between 3.3 V logic and 24 V industrial loads. Use Value: V_CE(sat) ≤ −1.5 V limits power dissipation to <150 mW at 100 mA, avoiding thermal shutdown during sustained duty cycles.
Smart HVAC Actuator	Medical Infusion Pump Driver
Use Scenario: Controlling small DC fan motors and damper positioners in residential HVAC control boards. IC Role / Device Role / Timing Role: Low-power, thermally efficient switching element activated by PWM signals from HVAC microcontroller. Use Value: 125 MHz f_T supports clean 25 kHz PWM operation with minimal switching distortion and EMI generation.	Use Scenario: Driving precision stepper motor phases and solenoid valves in battery-powered infusion pumps. IC Role / Device Role / Timing Role: Safety-critical load switch with validated AEC-Q101 reliability and −55 °C to +150 °C operational range. Use Value: R_JA = 417 °C/W on alumina substrate enables stable 300 mW operation without heatsink, conserving PCB space and weight.

Automotive Door Module

Industrial PLC Output Stage

Use Scenario: Driving 12 V window lift motor relays and door lock solenoids in centralized body control units.

IC Role / Device Role / Timing Role: High-gain PNP Darlington switch controlling inductive loads via MCU GPIO with <100 µA base current.

Use Value: Eliminates need for discrete driver stages; −30 V_CEO and −500 mA rating ensure robustness against load dump transients and coil flyback.

Use Scenario: Isolating and amplifying digital outputs from PLC CPU to 24 V DC field actuators (valves, indicators).

IC Role / Device Role / Timing Role: Level-shifting and current-boosting interface between 3.3 V logic and 24 V industrial loads.

Use Value: V_CE(sat) ≤ −1.5 V limits power dissipation to <150 mW at 100 mA, avoiding thermal shutdown during sustained duty cycles.

Smart HVAC Actuator

Medical Infusion Pump Driver

Use Scenario: Controlling small DC fan motors and damper positioners in residential HVAC control boards.

IC Role / Device Role / Timing Role: Low-power, thermally efficient switching element activated by PWM signals from HVAC microcontroller.

Use Value: 125 MHz f_T supports clean 25 kHz PWM operation with minimal switching distortion and EMI generation.

Use Scenario: Driving precision stepper motor phases and solenoid valves in battery-powered infusion pumps.

IC Role / Device Role / Timing Role: Safety-critical load switch with validated AEC-Q101 reliability and −55 °C to +150 °C operational range.

Use Value: R_JA = 417 °C/W on alumina substrate enables stable 300 mW operation without heatsink, conserving PCB space and weight.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBTA64LT1G	No "S" prefix; standard commercial grade (non-AEC-Q101 qualified); identical electrical specs and SOT-23 package.	Not approved for automotive production; suitable for industrial or consumer prototypes where qualification is not mandated.	Select MMBTA64LT1G for cost-sensitive non-automotive designs requiring same gain, voltage, and current ratings.
ZTX951	TO-92 package; higher V_CEO (−60 V); lower h_FE (min 500); larger footprint and manual assembly requirement.	Used in legacy through-hole designs or high-voltage analog circuits where SOT-23 density is unnecessary.	Choose ZTX951 only when TO-92 mounting, −60 V blocking, or legacy BOM compatibility is mandatory.

Compared with MMBTA64LT1G and ZTX951, the SMMBTA64LT1G uniquely combines AEC-Q101 qualification, SOT-23 miniaturization, and 20,000 h_FE - making it the sole option for space-constrained automotive modules requiring zero-derating operation at 125 °C ambient.

Availability

SMMBTA64LT1G is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, and medical fluid control systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SMMBTA64LT1G 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, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT applications.

The SMMBTA64LT1G belongs to onsemi's automotive-qualified discrete transistor family, engineered specifically for high-reliability, low-power switching in harsh-environment electronic control units.

FAQ

What is the maximum continuous collector current rating for the SMMBTA64LT1G?

The SMMBTA64LT1G has a maximum continuous collector current (I_C) rating of −500 mA at T_A = 25 °C. This rating applies to steady-state DC operation on an alumina substrate; derating is required above 25 °C at 2.4 mW/°C. The SMMBTA64LT1G must not be operated beyond this limit without thermal analysis confirming junction temperature remains within −55 °C to +150 °C.

Is the SMMBTA64LT1G pin-compatible with the MMBTA64LT1G?

Yes, the SMMBTA64LT1G is pin-compatible with the MMBTA64LT1G - both use identical SOT-23 (TO-236) package with BASE on Pin 1, EMITTER on Pin 2, and COLLECTOR on Pin 3. The only functional difference is the "S" prefix denoting AEC-Q101 qualification and PPAP capability; all electrical parameters, pinout, and thermal characteristics match per the shared datasheet.

Does the SMMBTA64LT1G include an internal base-emitter resistor?

No, the SMMBTA64LT1G does not include an internal base-emitter resistor. It is a bare Darlington transistor requiring external base current limiting. Unlike bias-resistor transistors (BRTs), the SMMBTA64LT1G provides full design flexibility for optimizing base drive strength and switching speed but mandates careful selection of the series base resistor based on V_BE(on) ≤ −2.0 V and target I_B.

What is the thermal resistance junction-to-ambient for the SMMBTA64LT1G on an FR-5 board?

The thermal resistance junction-to-ambient (R_JA) for the SMMBTA64LT1G on an FR-5 board is 556 °C/W, with a total device dissipation (P_D) of 225 mW at T_A = 25 °C. Derating is linear at 1.8 mW/°C above 25 °C. This value assumes the standard 1.0 × 0.75 × 0.062 inch FR-5 test board specified in the datasheet.

Can the SMMBTA64LT1G be used in 24 V automotive systems?

Yes, the SMMBTA64LT1G is rated for V_CES = −30 V and V_CBO = −30 V, providing sufficient margin for 24 V nominal automotive systems subject to load dump transients (up to +35 V) and reverse-battery protection circuits. Its AEC-Q101 qualification confirms robustness against vibration, temperature cycling, and humidity exposure typical in vehicle environments - making the SMMBTA64LT1G suitable for such applications.

SMMBTA64LT1G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: PNP - Darlington

Current - Collector (Ic) (Max):: 500 mA

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:: 20000 @ 100mA, 5V

Power - Max:: 225 mW

Frequency - Transition:: 125MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3 (TO-236)

SMMBTA64LT1G FAQ

1.How can I place an order for SMMBTA64LT1G through Aetrix?

Please submit a Request for Quotation (RFQ) for SMMBTA64LT1G 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 SMMBTA64LT1G reliable?

The price and inventory of SMMBTA64LT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMMBTA64LT1G is usually 5 days.

3.What payment methods are accepted for SMMBTA64LT1G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMMBTA64LT1G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SMMBTA64LT1G?

SMMBTA64LT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SMMBTA64LT1G 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 SMMBTA64LT1G?

For technical support, including SMMBTA64LT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMMBTA64LT1G requirements.

6.How does Aetrix verify that SMMBTA64LT1G is sourced from the original manufacturer or authorized distributors?

All SMMBTA64LT1G 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 SMMBTA64LT1G meets industry standards.

7.What is the process for return or replacement of SMMBTA64LT1G?

All SMMBTA64LT1G units undergo pre-shipment inspection (PSI). If there is an issue with SMMBTA64LT1G, 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 SMMBTA64LT1G part is unused and in its original packaging.

Return procedure for SMMBTA64LT1G:

1.Submit a request within 90 days.

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

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