Diodes Incorporated DDTC123TCA-7-F

Overview

DDTC123TCA-7-F 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 = 100–250. It serves as a compact, lead-free switching element in low-power digital interface and level-shifting circuits.

For engineers reviewing the DDTC123TCA-7-F datasheet, DDTC123TCA-7-F pinout, DDTC123TCA-7-F application, or DDTC123TCA-7-F equivalent, key selection criteria include R1 tolerance (±30%), thermal resistance (625 °C/W), AEC-Q101 qualification status (not applicable to this variant), SOT23 footprint compatibility, and DC current gain stability across −55°C to +150°C operating range.

Technical Context

This device implements a monolithic NPN bipolar junction transistor with integrated base biasing via a single external-resistor-equivalent structure (R1-only topology), eliminating discrete base resistors in simple on/off control paths. Its epitaxial planar die construction ensures consistent gain and saturation voltage performance across temperature.

Designed for direct-drive logic interfacing, it operates with fixed base current derived from input voltage through R1, enabling predictable turn-on behavior without external bias network tuning. The SOT23 package supports high-density PCB layouts while maintaining thermal dissipation capability up to 200 mW at T_A = 25°C with standard FR4 mounting.

Key Specifications

Pinout & Package

Package: SOT23 - Surface-mount plastic package with 3 terminals, 0.008 g mass, UL 94V-0 rated molding compound, and matte tin-plated leads compliant with MIL-STD-202 Method 208.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DDTC113TCA-7-F and DDTC143TCA-7-F, DDTC123TCA-7-F offers balanced base resistance for 3.3 V logic compatibility, wider h_FE range, and tighter V_CE(sat) specification-making it optimal for general-purpose 3.3 V/5 V interface switching where both drive strength and efficiency matter.

Availability

DDTC123TCA-7-F is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller GPIO expansion, and level-shifting interfaces requiring stable component supply and full RoHS 3 compliance.

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

This part belongs to the DDTC (R1-ONLY SERIES) CA family of pre-biased transistors designed specifically for space-constrained, cost-sensitive digital interface and switching applications in consumer, industrial, and computing equipment.

FAQ

What is the function of the internal resistor R1 in DDTC123TCA-7-F?

R1 is a 2.2 kΩ ±30% resistor connected between the base and emitter terminals. It provides fixed base biasing to simplify circuit design by eliminating the need for an external resistor. This configuration ensures predictable turn-on behavior when driven by logic-level voltages, reducing component count and PCB area.

Is DDTC123TCA-7-F qualified for automotive applications?

No. While the related DDTC143TCAQ-7-F variant is AEC-Q101 qualified and PPAP capable, DDTC123TCA-7-F is not automotive-grade. It is intended for commercial and industrial applications with operating temperature range −55°C to +150°C but lacks automotive change control, IATF 16949 traceability, or PPAP documentation.

Can DDTC123TCA-7-F replace a standard NPN transistor like BC847?

Yes, with circuit modification. Unlike BC847, DDTC123TCA-7-F has an internal R1, so it cannot be used as a bare transistor. To substitute, remove the external base resistor from the BC847 circuit and verify that the resulting base current meets the required I_C/I_B ratio (2.5 mA/0.25 mA) for saturation under your load conditions.

What is the maximum power dissipation for DDTC123TCA-7-F on a standard FR4 board?

The maximum power dissipation is 200 mW at T_A = +25°C when mounted on FR4 with Diodes' recommended minimum pad layout. Derating is required above 25°C ambient: power must decrease linearly at 0.32 mW/°C beyond 25°C, reaching zero at approximately 150°C case temperature.