Diodes Incorporated DDTA143ZUA-7

Overview

DDTA143ZUA-7 from Diodes Incorporated is a PNP pre-biased small-signal transistor in SOT-323 package, featuring built-in bias resistors R1 = 4.7 kΩ and R2 = 47 kΩ (R1 ≠ R2), DC current gain (h_FE) of 80 at I_C = −10 mA, V_CE(sat) ≤ −0.3 V, and −50 V collector-emitter breakdown voltage - used for level-shifting and digital switching in low-power logic interface circuits.

For engineers reviewing the DDTA143ZUA-7 datasheet, DDTA143ZUA-7 pinout, DDTA143ZUA-7 application, or DDTA143ZUA-7 equivalent, key selection criteria include input voltage thresholds (V_IN(on) = −2.5 V, V_IN(off) = −0.5 V), guaranteed saturation under −5 mA load, resistor tolerance (±30% on R1, ±20% on R2/R1 ratio), and thermal performance (R_θJA = 625 °C/W) on standard FR4 PCBs.

Technical Context

This device integrates a PNP bipolar junction transistor with two discrete external-base bias resistors (R1 connected to base, R2 from base to emitter), enabling single-resistor input drive and eliminating need for external bias network. Its R1 ≠ R2 topology provides asymmetric turn-on/turn-off behavior ideal for digital inversion and open-collector interface applications.

Designed for operation at V_CC = −50 V maximum and output current up to −100 mA, it delivers stable DC current gain (G_I = −80) across −55 °C to +150 °C ambient range, with f_T = 250 MHz ensuring adequate bandwidth for high-speed switching below 10 MHz.

Key Specifications

Pinout & Package

Package: SOT-323 - ultra-small surface-mount plastic case (2.0–2.2 mm × 1.15–1.35 mm × 0.25–0.40 mm height), RoHS-compliant, moisture sensitivity level 1, weight ≈ 0.006 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DDTA143ZUA-7, DDTA143FUA-7-F offers tighter input hysteresis for noisy rails, while DDTA123JUA-7-F lowers activation voltage for energy-constrained nodes - both retain identical SOT-323 footprint and thermal profile but differ in bias resistor ratios and resulting switching thresholds.

Availability

DDTA143ZUA-7 is available at Aetrix Electronics and suitable for logic interface design, LED driver circuits, and industrial I/O conditioning requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for DDTA143ZUA-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, with design centers across Asia and Europe, serving automotive, industrial, computing, and consumer markets.

This part belongs to the DDTA (R1≠R2 Series) UA family - engineered specifically for simplified digital switching in space-constrained PCBs where board area and assembly cost must be minimized without sacrificing reliability or temperature robustness.

FAQ

What is the absolute maximum input voltage for DDTA143ZUA-7?

The absolute maximum input voltage (V_IN) is specified as +7 V to −20 V per the datasheet's "Maximum Ratings" table. This range reflects safe operation under transient overvoltage conditions and ensures no damage occurs during logic-level transitions or ESD events, provided the input current remains within rated limits.

Can DDTA143ZUA-7 replace a standard PNP BJT like BC807 in existing designs?

No - DDTA143ZUA-7 integrates internal bias resistors and operates as a digitally optimized switch, not a general-purpose amplifier. Replacing BC807 requires verifying that the fixed R1/R2 network meets the new circuit's base drive requirements and that V_IN(on)/V_IN(off) thresholds align with upstream logic levels.

Is the SOT-323 package compatible with reflow soldering per J-STD-020?

Yes - the SOT-323 package is qualified for lead-free reflow per J-STD-020C, with moisture sensitivity level 1 (unlimited floor life at ≤30 °C/60% RH), and supports peak temperatures up to 260 °C for ≤30 seconds, matching standard Pb-free process profiles used in high-volume SMT lines.

How does the R1 ≠ R2 architecture improve noise immunity compared to R1 = R2 pre-biased transistors?

The asymmetric resistor ratio creates unequal turn-on and turn-off thresholds (e.g., V_IN(on) = −2.5 V, V_IN(off) = −0.5 V), yielding ~2 V hysteresis. This prevents oscillation or chatter during slow-rising/falling edges or in electrically noisy environments where input signals may cross the switching point multiple times.