Diodes Incorporated DDTB122TU-7

Overview

DDTB122TU-7 from Diodes Incorporated is a PNP pre-biased transistor in SOT-323 package, rated for −500 mA output current, −40 V collector-emitter breakdown (BV_CEO), and −5 V emitter-base breakdown (BVEBO), used as a compact load switch or level translator in low-voltage logic interface circuits.

For engineers reviewing the DDTB122TU-7 datasheet, DDTB122TU-7 pinout, DDTB122TU-7 application, or DDTB122TU-7 equivalent, key selection criteria include its R1-only bias configuration (22 kΩ), h_FE range of 100–600 at −5 mA/−5 V, −0.3 V V_CE(sat), and SOT-323 thermal resistance of 625 °C/W.

Technical Context

This device integrates a single PNP bipolar junction transistor with an internal 22 kΩ base-emitter pull-up resistor (R1) and no second bias resistor (R2 = open), enabling direct TTL/CMOS-compatible input drive without external components. It operates with V_EB up to −5 V and supports switching at DC to 200 MHz (f_T).

The SOT-323 package provides surface-mount compatibility with FR4 board mounting per AP02001 layout guidelines, delivering 200 mW power dissipation at 25 °C ambient and derating linearly to zero at 150 °C junction temperature.

Key Specifications

Pinout & Package

SOT-323 plastic surface-mount package: 2.2 mm × 1.35 mm × 0.9 mm body, UL 94V-0 rated, matte tin-plated terminals, moisture sensitivity Level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DDTB122JU-7, DDTB122TU-7 offers higher input threshold (−5 V vs −2 V) for improved noise immunity in noisy industrial environments; versus NSV12200MT1G, it delivers five times the output current and superior thermal performance in the same footprint class.

Availability

DDTB122TU-7 is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller I/O expansion, and industrial sensor interface designs requiring stable component supply and long-term manufacturability.

Supply support for DDTB122TU-7 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, serving automotive, industrial, computing, and consumer markets with AEC-Q101-qualified components.

The DDTB series targets cost-sensitive, high-volume logic interface and load switching applications, emphasizing integration, small form factor, and robust parametric consistency across temperature and process variation.

FAQ

What is the function of the open R2 terminal in DDTB122TU-7?

The R2 terminal is internally left unconnected (open), resulting in a single-resistor (R1-only) bias configuration. This design sets the input threshold at −5 V (BVEBO), making the device ideal for applications where high noise immunity and direct compatibility with negative-going logic signals are required, without needing a second resistor to set precise input hysteresis.

Can DDTB122TU-7 replace a standard PNP transistor like BC807 in existing designs?

Yes, but only if the base drive circuitry is adapted to accommodate the integrated 22 kΩ R1 resistor. Unlike BC807, DDTB122TU-7 does not require an external base resistor for basic switching, but its fixed bias network alters input impedance and switching thresholds-designers must verify VIH/VIL compatibility and recalculate timing margins before substitution.

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

At 85 °C ambient, the power derating curve (Fig. 1) shows ~120 mW max dissipation. With V_CE(sat) = −0.3 V, the corresponding I_C limit is approximately −400 mA (P = V × I → 120 mW / 0.3 V = 400 mA), assuming negligible base current contribution and proper PCB copper area per AP02001 layout guidelines.

Is DDTB122TU-7 suitable for analog amplification applications?

No-it is optimized for switching, not linear amplification. Its h_FE variation (100–600), lack of guaranteed linearity specs, and absence of AC small-signal parameters (e.g., r_π, C_ob) in the datasheet confirm its intended use as a digital switch or level translator, not an amplifier stage.