Diodes Incorporated DDTC144TKA-7-F

Overview

DDTC144TKA-7-F from Diodes Incorporated is an NPN pre-biased small-signal transistor with single built-in bias resistor (R1 = 47 kΩ), SC-59 package, V_CEO = 50 V, I_C(max) = 100 mA, and h_FE = 100–600 at I_C = 1 mA. It serves as a compact, integrated switch in low-power digital interface circuits.

For engineers reviewing the DDTC144TKA-7-F datasheet, DDTC144TKA-7-F pinout, DDTC144TKA-7-F application, or DDTC144TKA-7-F equivalent, key selection criteria include R1 tolerance (±30%), V_CE(sat) ≤ 0.3 V at I_C/I_B = 1 mA/0.1 mA, thermal resistance (625 °C/W), and SC-59 footprint compatibility with space-constrained PCB layouts.

Technical Context

This device integrates a single base biasing resistor (R1 only, no R2), simplifying external component count in saturated-switch applications. Its epitaxial planar construction ensures stable h_FE and low leakage (I_CBO, I_EBO ≤ 0.5 μA), while the SC-59 package supports automated SMT assembly and meets J-STD-020C Level 1 moisture sensitivity.

Designed for DC-coupled switching-not linear amplification-it operates with fixed base current derived from input voltage via R1, delivering predictable saturation behavior under I_C/I_B = 10 conditions. The "KA" suffix denotes SC-59 packaging and green molding compound compliance.

Key Specifications

Pinout & Package

Package: SC-59 - 3-pin surface-mount plastic package (JEDEC TO-236AB), 2.7–3.0 mm length, 1.5–1.7 mm width, 0.35–0.50 mm thickness, UL 94V-0 rated, lead-free matte tin plating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DDTC144EUA-7-F and NSV144T1T1G, DDTC144TKA-7-F offers the best balance of guaranteed h_FE margin, lowest V_CE(sat), and proven thermal performance in the widely adopted SC-59 footprint-making it optimal for production designs requiring reliability over miniaturization or cost trade-offs.

Availability

DDTC144TKA-7-F is available at Aetrix Electronics and suitable for LED driver interfaces, microcontroller GPIO expansion, and power rail enable switching requiring stable component supply, consistent parametric performance, and long-term industrial availability.

Supply support for DDTC144TKA-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, application-optimized components for industrial, computing, and consumer markets.

The DDTC (R1-only series) product line delivers pre-biased transistors optimized for simplified digital switching in space- and cost-sensitive applications-reducing design complexity while maintaining robust parametric consistency across temperature and process variation.

FAQ

What is the function of the "KA" suffix in DDTC144TKA-7-F?

The "KA" suffix identifies the SC-59 package variant with green (halogen-free) molding compound and matte tin lead finish. It distinguishes this version from other packages (e.g., "K" for SOT-23, "UA" for SOT-323) and confirms compliance with Diodes Inc.'s environmental policies effective from date code 0627 onward.

Can DDTC144TKA-7-F be used in linear amplifier configurations?

No. This device is specifically designed and characterized for saturated switching operation. Its h_FE specification is given at I_C = 1 mA and V_CE = 5 V, and no small-signal parameters (e.g., r_π, g_m) or frequency response data beyond f_T = 250 MHz (for reference only) are provided-making it unsuitable for analog amplification.

Is a flyback diode required when switching inductive loads?

Yes. Although V_CEO = 50 V provides headroom, the device lacks integrated clamp protection. When driving relays or solenoids, an external flyback diode (e.g., 1N4148) must be placed across the load to suppress inductive voltage spikes that exceed V_CEO and risk junction breakdown.

How does R1 tolerance affect switching performance?

R1 tolerance (±30%) directly impacts base current: at 5 V input, R1 ranges from 32.9 kΩ to 61.1 kΩ, yielding I_B from 82 μA to 152 μA. With h_FE ≥ 100, this still ensures I_C ≥ 8.2 mA - sufficient for most indicator and logic-level loads, but marginal for 100 mA switching at high temperature or low V_CC.