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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single, Pre-Biased Bipolar Transistors

Diodes Incorporated DDTC125TCA-7-F

Name: DDTC125TCA-7-F
Brand: Diodes Incorporated
SKU: DDTC125TCA-7-F
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: DDTC125TCA-7-F

Manufacturer:: Diodes Incorporated

Category:: Single, Pre-Biased Bipolar Transistors

Package:: -

Datasheet:: DDTC125TCA-7-F.pdf

Description:: TRANS PREBIAS NPN 200MW SOT23-3

Quantity:: RFQ Add To RFQ list

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Inventory:9,000

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Product details

Overview

DDTC125TCA-7-F from Diodes Incorporated is an NPN pre-biased transistor in SOT23 package with a single built-in 200 kΩ bias resistor (R1), 50 V V_CEO, 100 mA I_C, h_FE of 100–600 at I_C = 1–5 mA, and V_CE(sat) ≤ 0.3 V. It serves as a compact, lead-free switching element in low-power digital interface and level-shifting circuits.

For engineers reviewing the DDTC125TCA-7-F datasheet, DDTC125TCA-7-F pinout, DDTC125TCA-7-F application, or DDTC125TCA-7-F equivalent, key selection factors include its R1-only biasing topology, SOT23 thermal resistance (625 °C/W), guaranteed h_FE range across operating current, and obsolescence status requiring supply-chain planning.

Technical Context

This device implements a monolithic NPN bipolar junction transistor with an integrated 200 kΩ base bias resistor (R1), eliminating external bias components. It operates in saturation or cutoff mode for digital switching, not linear amplification.

Designed for discrete logic-level translation and load switching, it supports V_CB up to 50 V and V_EB up to 5 V, with guaranteed leakage (I_CBO, I_EBO) ≤ 0.5 μA and f_T = 250 MHz - confirming high-speed switching capability despite its DC gain focus.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	50 V - Maximum collector-emitter voltage before breakdown; defines safe operating voltage in switching applications.
I_C (Max)	100 mA - Continuous collector current limit; sets maximum load drive capability without derating.
R1	200 kΩ ±30% - Single integrated base bias resistor; eliminates need for external bias network in simple switch designs.
h_FE	100–600 - DC current gain range at I_C = 1–5 mA; ensures reliable saturation with low base drive current.
V_CE(sat)	≤ 0.3 V at I_C/I_B = 0.5 mA/0.05 mA - Low saturation voltage minimizes power loss and heating in on-state operation.
P_D	200 mW - Maximum power dissipation on FR4 board; constrains usable duty cycle and ambient temperature range.
R_θJA	625 °C/W - Junction-to-ambient thermal resistance; requires careful PCB copper area design for thermal management.

Pinout & Package

Package: SOT23 - surface-mount plastic package with 3 terminals, 0.008 g mass, UL 94V-0 rating, and moisture sensitivity level 1.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Emitter terminal	Reference node for current flow; connected to ground or low-side return path in common-emitter switch configuration.
2 (Base)	Base terminal with internal R1 connection	Input control node; internally tied to 200 kΩ resistor (R1) between pin 2 and pin 3 - no external base resistor required.
3 (Collector)	Collector terminal	Output/load connection point; sinks current when saturated; rated for 50 V and 100 mA continuous operation.

Key Features

Feature	Design Value
R1-only biasing	Single 200 kΩ integrated base resistor simplifies PCB layout and reduces BOM count for basic switching functions.
AEC-Q101 qualified variants available	DDTC143TCAQ demonstrates automotive qualification path; confirms robustness of R1-series process for mission-critical use.
Lead-free & halogen-free	Meets RoHS 2/3 and "Green" standards (<900 ppm Br/Cl, <1000 ppm Sb); suitable for environmentally regulated industrial production.
SOT23 footprint compatibility	Standardized 3-pin SOT23 outline enables drop-in replacement with other small-signal transistors in space-constrained layouts.

Applications

LED Driver Interface

Microcontroller GPIO Expander

Use Scenario: Driving indicator LEDs from 3.3 V or 5 V MCU outputs with current limiting via collector load.

IC Role / Device Role / Timing Role: NPN switch controlling LED anode/cathode current path; operates in saturation/cutoff with <1 µs turn-on/off.

Use Value: Eliminates need for discrete base resistor; 0.3 V V_CE(sat) ensures >90% LED forward voltage utilization at 10–20 mA.

Use Scenario: Extending limited GPIO count by enabling/disabling peripheral enable lines or reset signals.

IC Role / Device Role / Timing Role: Level-shifting buffer for active-low enable signals; provides isolation and current gain between MCU and downstream ICs.

Use Value: 200 kΩ R1 allows direct MCU pin drive without pull-up/down conflicts; h_FE ≥ 100 ensures full saturation with ≤50 µA base current.

Low-Power Sensor Interface

Power Sequencing Control

Use Scenario: Enabling/disabling analog sensor supply rails (e.g., 3.3 V LDO output) based on system sleep/wake state.

IC Role / Device Role / Timing Role: High-side or low-side load switch controlled by microcontroller wake signal.

Use Value: 50 V V_CEO and 100 mA rating support typical sensor rail currents; low I_CBO ≤ 0.5 µA prevents standby leakage.

Use Scenario: Controlling power-up sequence of multi-rail systems (e.g., FPGA core/I/O voltages) using timed GPIO signals.

IC Role / Device Role / Timing Role: Discrete timing delay element via RC network at base, leveraging R1 and external capacitor.

Use Value: Integrated R1 enables precise, repeatable turn-on delay (e.g., 10–100 ms) without additional resistors; stable h_FE ensures consistent threshold.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN pre-biased transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
DDTC124TCA-7-F	22 kΩ R1 (vs. 200 kΩ); h_FE 60–630; same SOT23 package and V_CEO/I_C ratings.	Higher base current draw; better suited for higher-speed switching or lower-V_CC (1.8–2.5 V) logic interfaces.	Select when driving heavier loads or interfacing with low-threshold logic families requiring stronger base drive.
DDTC144TCA-7-F	47 kΩ R1; h_FE 60–630; identical absolute max ratings and thermal specs.	Intermediate bias strength; balances speed and power efficiency for 3.3 V MCU interfaces with moderate fan-out.	Prefer for general-purpose 3.3 V digital switching where 200 kΩ R1 may cause marginal saturation under temperature variation.

Compared with DDTC124TCA-7-F and DDTC144TCA-7-F, DDTC125TCA-7-F's 200 kΩ R1 delivers lowest base current demand and highest input impedance, making it optimal for ultra-low-power wake-up circuits - but less tolerant of V_BE drift at elevated temperature.

Availability

DDTC125TCA-7-F is available at Aetrix Electronics and suitable for LED driver interface, microcontroller GPIO expansion, and low-power sensor interface applications requiring stable component supply and legacy design continuity.

Supply support for DDTC125TCA-7-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, energy-efficient components for industrial, computing, and consumer markets.

This part belongs to the DDTC (R1-only series) pre-biased transistor family, engineered to reduce component count and improve assembly yield in cost-sensitive digital switching applications.

FAQ

Is DDTC125TCA-7-F still in active production?

No - DDTC125TCA-7-F is marked as Obsolete in Diodes' official ordering information. It remains available through Aetrix Electronics' legacy inventory and authorized distribution channels, but new design-ins should consider functional alternatives like DDTC124TCA-7-F or DDTC144TCA-7-F with updated R1 values and active status.

What is the function of the "R1-only" configuration?

The "R1-only" designation means this transistor integrates only one base-emitter bias resistor (200 kΩ), connecting internally between base (pin 2) and collector (pin 3). Unlike dual-resistor (R1+R2) pre-biased transistors, it lacks an emitter-base resistor, requiring external pull-down or defined logic states to ensure clean cutoff.

Can DDTC125TCA-7-F be used in automotive applications?

DDTC125TCA-7-F itself is not AEC-Q101 qualified. However, the same R1-only series includes automotive-grade variants (e.g., DDTC143TCAQ-7-F), which share identical electrical characteristics and SOT23 packaging but are manufactured in IATF 16949-certified facilities and PPAP-capable.

How does the 200 kΩ R1 affect base drive requirements?

With R1 = 200 kΩ, base current is approximately (V_IN − 0.7 V)/200 kΩ - e.g., ~15 µA at 3.3 V. This enables direct drive from low-current GPIOs, but requires verification of h_FE × I_B ≥ I_C under worst-case temperature and voltage to guarantee saturation.

DDTC125TCA-7-F Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: *

Package/Case:: -

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: -

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

Voltage - Collector Emitter Breakdown (Max):: -

Resistor - Base (R1):: -

Resistor - Emitter Base (R2):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: -

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: -

Frequency - Transition:: -

Power - Max:: -

Grade:: -

Qualification:: -

Mounting Type:: -

Supplier Device Package:: -

DDTC125TCA-7-F FAQ

1.How can I place an order for DDTC125TCA-7-F through Aetrix?

Please submit a Request for Quotation (RFQ) for DDTC125TCA-7-F 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 DDTC125TCA-7-F reliable?

The price and inventory of DDTC125TCA-7-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DDTC125TCA-7-F is usually 5 days.

3.What payment methods are accepted for DDTC125TCA-7-F?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DDTC125TCA-7-F transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for DDTC125TCA-7-F?

DDTC125TCA-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your DDTC125TCA-7-F 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 DDTC125TCA-7-F?

For technical support, including DDTC125TCA-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DDTC125TCA-7-F requirements.

6.How does Aetrix verify that DDTC125TCA-7-F is sourced from the original manufacturer or authorized distributors?

All DDTC125TCA-7-F 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 DDTC125TCA-7-F meets industry standards.

7.What is the process for return or replacement of DDTC125TCA-7-F?

All DDTC125TCA-7-F units undergo pre-shipment inspection (PSI). If there is an issue with DDTC125TCA-7-F, 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 DDTC125TCA-7-F part is unused and in its original packaging.

Return procedure for DDTC125TCA-7-F:

1.Submit a request within 90 days.

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

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