Diodes Incorporated DDTC143EKA-7-F

Overview

DDTC143EKA-7-F from Diodes Incorporated is an NPN pre-biased small-signal transistor in SC-59 package with built-in bias resistors R1 = R2 = 4.7 kΩ, V_CC = 50 V, I_O = 100 mA, P_D = 200 mW, and DC current gain (h_FE) ≥ 20 at I_C = 20 mA - used for digital switching in logic-level interface circuits.

For engineers reviewing the DDTC143EKA-7-F datasheet, DDTC143EKA-7-F pinout, DDTC143EKA-7-F application, or DDTC143EKA-7-F equivalent, key selection criteria include input voltage thresholds (V_IN(on) = 1.9 V typ), output saturation voltage (V_CE(SAT) ≤ 0.3 V), resistor tolerance (±30%), thermal resistance (625 °C/W), and SC-59 mechanical compatibility.

Technical Context

This device integrates two matched 4.7 kΩ biasing resistors (R1 = R2) to configure a single-NPN digital switch with fixed base drive, eliminating external bias components. It operates as a saturated switch with guaranteed turn-on at V_IN ≥ 1.9 V and turn-off at V_IN ≤ 1.1 V under standard test conditions.

The transistor uses epitaxial planar die construction for stable h_FE (≥20) across temperature (–55°C to +150°C), supports 100 mA continuous output current, and features a gain-bandwidth product of 250 MHz - suitable for low-speed digital signal routing, not RF amplification.

Key Specifications

Pinout & Package

Package: SC-59 surface-mount plastic package (JEDEC TO-236AB), 3-terminal, lead-free/RoHS-compliant, moisture sensitivity level 1, weight ≈ 0.008 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DDTC143EKA-7-F, DDTC143ZCA-7-F saves board area but sacrifices thermal performance, while NSV143EWT1G offers tighter parametric control and higher minimum gain - both retain identical bias topology and functional pinout.

Availability

DDTC143EKA-7-F is available at Aetrix Electronics and suitable for logic-level interface, microcontroller GPIO expansion, and industrial I/O buffering requiring stable component supply, consistent parametric performance, and RoHS-compliant manufacturing.

Supply support for DDTC143EKA-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, energy-efficient components for industrial, computing, and automotive markets.

This part belongs to the DDTC R1 = R2 series of pre-biased transistors, designed specifically to simplify digital switching in space- and cost-sensitive applications by integrating matched bias resistors into standard SMT packages.

FAQ

What is the function of Pin 3 (Base) in DDTC143EKA-7-F?

Pin 3 is the base terminal internally connected to the junction of two 4.7 kΩ resistors (R1 and R2). It serves as the input node for logic-level signals - applying voltage here forward-biases the NPN transistor through R1, while R2 provides base-emitter shunt path for reliable turn-off. No external resistor is needed.

Can DDTC143EKA-7-F replace a standard 2N3904 with external bias resistors?

Yes - it replaces a 2N3904 plus two discrete 4.7 kΩ resistors in digital switch applications. Its integrated bias network delivers identical DC operating point (I_B ≈ 1.8 mA at V_IN = 5 V), but with tighter resistor matching, reduced layout sensitivity, and guaranteed V_IN(on)/V_IN(off) thresholds.

Is DDTC143EKA-7-F qualified for automotive use?

While not AEC-Q101 certified out-of-box, Diodes Incorporated qualifies this device to operate across –55°C to +150°C junction temperature and publishes automotive-grade reliability data. Customers requiring formal qualification should consult Diodes' AEC-Q101 report for DDTC143EKA-7-F or select the pin-compatible NSV143EWT1G variant.

What is the maximum safe continuous collector current at 85°C ambient?

At T_A = 85°C, derating begins at 625 °C/W: P_D = 200 mW × (1 − (85 − 25)/625) = 180.8 mW. With V_CE(SAT) ≤ 0.3 V, max I_C = P_D/V_CE(SAT) ≈ 600 mA - but absolute maximum rating remains 100 mA per datasheet, so 100 mA is the hard limit regardless of thermal headroom.