Diodes Incorporated DDTC123TCA-7

Overview

DDTC123TCA-7 from Diodes Incorporated is an NPN pre-biased transistor in SOT23 package with a single built-in 2.2 kΩ bias resistor (R1), V_CEO = 50 V, I_C(max) = 100 mA, V_CE(sat) ≤ 0.3 V at I_C/I_B = 2.5 mA/0.25 mA, and h_FE = 100–600. It is used for digital switching in low-power logic interface circuits.

For engineers reviewing the DDTC123TCA-7 datasheet, DDTC123TCA-7 pinout, DDTC123TCA-7 application, or DDTC123TCA-7 equivalent, key selection criteria include input resistor value (2.2 kΩ), saturation voltage under defined drive conditions, DC current gain range, thermal derating on FR4, and compatibility with 3.3 V/5 V logic-level control signals.

Technical Context

This device integrates a single base bias resistor (R1 only, no R2), simplifying PCB layout versus discrete resistor-transistor combinations. Its epitaxial planar construction ensures stable h_FE across temperature (−55°C to +150°C) and consistent V_CE(sat) performance at I_C/I_B = 2.5 mA/0.25 mA.

Designed for logic-level switching, it operates with minimal external components: base driven directly by MCU GPIO or gate driver output; collector load connected to supply; emitter grounded. No external base resistor required due to integrated 2.2 kΩ R1.

Key Specifications

Pinout & Package

Package: SOT23 - Surface-mount plastic package (2.9 mm × 1.3 mm × 1.0 mm), moisture sensitivity level 1, matte tin-plated leads, UL 94V-0 rated molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DDTC113TCA-7 and DDTC143TCA-7, the DDTC123TCA-7 strikes a balanced trade-off: its 2.2 kΩ R1 delivers adequate base current for reliable 3.3 V/5 V logic drive while maintaining low static power draw and robust saturation performance across temperature.

Availability

DDTC123TCA-7 is available at Aetrix Electronics and suitable for LED interface circuits, microcontroller GPIO expansion, and low-power relay control requiring stable component supply and long-term production continuity.

Supply support for DDTC123TCA-7 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, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The DDTC (R1-only series) CA family targets cost-sensitive, space-constrained digital switching applications-designed specifically to replace discrete BJT + resistor combinations in consumer, industrial, and automotive subsystems.

FAQ

What is the function of the internal resistor in DDTC123TCA-7?

The internal 2.2 kΩ resistor (R1) connects between the base and emitter terminals, providing automatic biasing for NPN transistor operation. It eliminates the need for an external base resistor, simplifies PCB layout, and ensures consistent turn-on behavior with standard logic-level inputs (3.3 V or 5 V). This resistor sets the base current based on applied input voltage, enabling predictable saturation without additional components.

Can DDTC123TCA-7 be used in automotive applications?

DDTC123TCA-7 itself is not AEC-Q101 qualified; however, its pin-compatible variant DDTC143TCAQ-7-F is fully AEC-Q101 qualified, PPAP capable, and manufactured in IATF 16949 certified facilities. For automotive-grade designs, engineers should specify the Q-suffix version, which shares identical electrical characteristics and SOT23 packaging but undergoes extended reliability testing per automotive standards.

How does the SOT23 package affect thermal performance?

In the SOT23 package, DDTC123TCA-7 achieves a thermal resistance of R_θJA = 625°C/W on a standard FR4 PCB with minimum recommended pad layout. This means a 200 mW power dissipation results in ~125°C junction-to-ambient rise above ambient temperature. To maintain safe operation below 150°C T_J, ambient must stay below 25°C at full power-or derating is required per Figure 1 in the datasheet for higher ambient temperatures.

What is the significance of the "CA" suffix in DDTC123TCA-7?

The "CA" suffix denotes the specific product variant within Diodes' DDTC R1-only series, indicating compliance with halogen- and antimony-free "Green" specifications (<900 ppm Br, <900 ppm Cl, <1000 ppm Sb), RoHS 3 compliance, and matte tin-plated leads. It distinguishes this environmentally optimized version from legacy variants and confirms suitability for modern eco-conscious manufacturing and export requirements.