Diodes Incorporated DDTD122LC-7-F

Overview

DDTD122LC-7-F from Diodes Incorporated is an NPN pre-biased digital transistor in SOT23 package, featuring integrated 220 kΩ input resistor (R1) and 10 kΩ base-emitter resistor (R2), 500 mA continuous collector current, 50 V V_CBO, and 0.3 V V_CE(sat) at I_C = 50 mA / I_B = 2.5 mA - used for logic-level switching in automotive body control modules.

For engineers reviewing the DDTD122LC-7-F datasheet, DDTD122LC-7-F pinout, DDTD122LC-7-F application, or DDTD122LC-7-F equivalent, key selection criteria include verified R1/R2 resistor values, guaranteed V_CE(sat) under 50 mA load, SOT23 thermal derating behavior, and AEC-Q101 qualification status for automotive use cases.

Technical Context

This device integrates two precision biasing resistors to eliminate external components in saturated-switch configurations. It operates as a single-stage inverter with defined logic thresholds: V_IN(OFF) ≤ 0.3 V and V_IN(ON) ≥ 2.0 V at I_O = 20 mA, enabling direct interface with 3.3 V and 5 V microcontrollers.

The internal NPN die uses epitaxial planar construction for stable h_FE and f_T = 200 MHz, supporting fast switching in LED drivers and relay drivers where propagation delay and rise/fall time are design-critical.

Key Specifications

Pinout & Package

Package: SOT23 - surface-mount, 3-terminal plastic package with 0.915 mm lead pitch, 2.40 mm body length, and 1.30 mm body width; UL 94V-0 rated, 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 DDTD122LC-7-F, DDTB122LC-7-F offers complementary polarity for push-pull stages, while NSVD122DXV6T1G adds 10 V headroom on V_CBO and extended AEC-Q101 test coverage - both retain identical bias network topology and SOT23 footprint.

Availability

DDTD122LC-7-F is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC output modules, LED signage drivers, and USB-C power path control requiring stable component supply and traceable sourcing.

Supply support for DDTD122LC-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 DDTD series of pre-biased transistors designed specifically for automotive and industrial logic-level switching applications where reliability, small footprint, and reduced external component count are critical.

FAQ

Is DDTD122LC-7-F AEC-Q101 qualified?

No - DDTD122LC-7-F is marked "Obsolete" in Diodes' ordering information and is not AEC-Q101 qualified. Its datasheet states that automotive-grade variants require explicit contact with Diodes representatives for PPAP-capable, IATF 16949-manufactured parts. For qualified alternatives, consider NSVD122DXV6T1G or DDTB122LC-7-F with confirmed AEC-Q101 reports.

What is the exact resistor configuration inside DDTD122LC-7-F?

DDTD122LC-7-F contains a 220 kΩ resistor (R1) between pin 1 (emitter) and pin 2 (base), and a 10 kΩ resistor (R2) between pin 2 (base) and pin 3 (collector). This matches the "R1/R2 Type" schematic shown in DS30399 Rev. 9–2, page 2, and is confirmed by electrical test conditions for V_IN(ON) and I_L.

Can DDTD122LC-7-F replace a standard 2N3904 with external bias resistors?

Yes - it replaces a 2N3904 plus two discrete resistors in saturated-switch applications. Its integrated R1/R2 network provides identical biasing functionality, with verified V_CE(sat) ≤ 0.3 V and I_C = 500 mA rating exceeding 2N3904's 200 mA limit, making it suitable for higher-current loads without redesigning the bias network.

What is the thermal resistance of DDTD122LC-7-F on a standard PCB?

R_θJA is 500 °C/W when mounted on a 1-oz single-sided FR4 PCB with Diodes' recommended pad layout (C = 2.0 × 0.8 mm, X1 = 1.35 mm). This value drops significantly with copper pour or thermal vias - actual junction temperature must be calculated using P_D = 250 mW and ambient temperature per Figure 1 derating curve.