Diodes Incorporated DDTC122TU-7-F

Overview

DDTC122TU-7-F from Diodes Incorporated is an NPN pre-biased digital transistor in SOT-323 package, featuring integrated 220 Ω base resistor (R1) and open-emitter configuration (R2 = OPEN), rated for 100 mA output current, 50 V V_CBO, and 5 V V_EBO. It functions as a single-stage logic-level switch in low-power signal routing applications such as LED driver control and microcontroller I/O buffering.

For engineers reviewing the DDTC122TU-7-F datasheet, DDTC122TU-7-F pinout, DDTC122TU-7-F application, or DDTC122TU-7-F equivalent, key selection criteria include its R1-only bias network, 100–600 h_FE range at 1 mA, 0.3 V V_CE(sat) at 5 mA/0.25 mA, SOT-323 thermal resistance (625 °C/W), and automotive-grade qualification readiness.

Technical Context

This device implements a monolithic NPN transistor with on-die base-emitter resistor (R1 = 220 Ω nominal) and no second resistor (R2 = OPEN), enabling direct TTL/CMOS-compatible input drive without external bias components. Its epitaxial planar construction ensures stable gain and switching behavior across -55 °C to +150 °C.

The SOT-323 package supports surface-mount assembly with JEDEC-compliant pad layout, moisture sensitivity level 1, and 0.006 g mass. Electrical operation is defined by V_EBO = 5 V (max), I_C = 100 mA (continuous), P_D = 200 mW (on FR4), and f_T = 200 MHz - confirming suitability for DC and low-frequency (<10 MHz) switching only.

Key Specifications

Pinout & Package

Package: SOT-323 - ultra-small surface-mount plastic case (2.0 × 1.25 × 0.9 mm), UL 94V-0 rated, lead-free matte tin plating, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DDTC122TU-7-F, DDTC122TK-7-F trades miniaturization for thermal headroom, while NSV122TUTBG adds automotive qualification rigor and tighter gain control - both retain identical bias topology and pin compatibility in their respective packages.

Availability

DDTC122TU-7-F is available at Aetrix Electronics and suitable for LED indicator control, microcontroller I/O buffering, logic-level signal inversion, and low-power sensor interface applications requiring stable component supply and long-term obsolescence management.

Supply support for DDTC122TU-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 the Americas.

The DDTC series belongs to Diodes' pre-biased transistor product line, engineered specifically for reducing bill-of-materials count and PCB area in digital interface and low-power switching applications across consumer, industrial, and automotive markets.

FAQ

Is DDTC122TU-7-F still in active production?

No - DDTC122TU-7-F is officially marked obsolete per Diodes' DS30401 Rev. 7-4 (June 2021). Aetrix Electronics maintains limited legacy stock and supports cross-reference engineering for replacement solutions with validated alternatives like NSV122TUTBG or DDTC122TK-7-F.

What does "R2 = OPEN" mean in the DDTC122TU-7-F marking table?

"R2 = OPEN" indicates the absence of a second integrated resistor between base and emitter. This configuration allows the emitter to be externally biased - for example, pulled up to V_CC to implement an inverting switch, or grounded for standard low-side switching - giving designers flexibility beyond fixed-resistor topologies.

Can DDTC122TU-7-F replace a standard 2N3904 in a circuit?

Only with schematic modification: DDTC122TU-7-F integrates a 220 Ω base resistor and lacks a standalone base terminal. It cannot substitute for a bare 2N3904 without removing external bias resistors and verifying that the resulting drive strength and saturation behavior meet system requirements - particularly V_CE(sat) and switching speed.

Does DDTC122TU-7-F support 1.8 V logic input levels?

No - the device's V_I(off) is specified at 0.3 V (max), but V_I(on) is not characterized below 2.0 V. At 1.8 V input, base current may be insufficient to guarantee saturation across process/voltage/temperature extremes; use only with ≥3.3 V logic families unless validated per application.