Diodes Incorporated ZLDO330T8TA

Overview

ZLDO330T8TA from Diodes Incorporated (formerly Zetex) is an ultra-low dropout linear regulator delivering a fixed 3.3 V output with 300 mA load capability, 30 mV dropout at 100 mA, 560 µA typical quiescent current, and integrated low-battery flag (open-collector LBF) and active-high shutdown control - used in battery-powered logic supplies where input-to-output margin is as low as 4.3 V.

For engineers reviewing the ZLDO330T8TA datasheet, ZLDO330T8TA pinout, ZLDO330T8TA application, or ZLDO330T8TA equivalent, key selection criteria include dropout voltage vs. load, shutdown quiescent current (11 µA), LBF threshold accuracy (V_IN = V_OUT + 0.2–0.4 V), thermal shutdown at 125°C, and SM8 package layout constraints.

Technical Context

The ZLDO330T8TA employs a precision bandgap reference and error amplifier with external shaping capacitor (10 pF from Pin 8 to Pin 5) to ensure stability across 10 mA–300 mA loads. Its low-dropout PNP pass transistor enables regulation down to 6 mV dropout at 10 mA and maintains ±2.5% output tolerance over –40°C to +85°C.

It integrates two independent monitoring functions: a low-battery comparator that asserts LBF when V_IN falls within 200–400 mV of V_OUT, and thermal shutdown triggered at junction temperature >125°C. Shutdown control (Pin 2) draws <10 µA and reduces I_Q to 11 µA typical.

Key Specifications

Pinout & Package

Package: SM8 (8-pin small-outline surface-mount), 5.0 mm × 6.2 mm footprint, exposed pad not electrically connected. Thermal resistance θ_JA ≈ 65°C/W on 2-inch² PCB (Note 1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-dropout regulator applications.

Compared with MCP1700T-3302E/TT and TPS76333DBVR, the ZLDO330T8TA uniquely combines 300 mA capability, sub-30 mV dropout, integrated LBF, and shutdown - making it irreplaceable in battery-fail-aware portable designs where both performance and predictive power management are required.

Availability

ZLDO330T8TA is available at Aetrix Electronics and suitable for portable medical sensors, handheld test equipment, and industrial data loggers requiring stable component supply with long-term availability assurance.

Supply support for ZLDO330T8TA 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-efficiency power management and signal integrity solutions for industrial, computing, and consumer markets.

The ZLDO series was designed specifically for ultra-low-voltage-margin battery-powered systems requiring predictable failure signaling and minimal quiescent consumption - targeting portable instrumentation and legacy embedded platforms.

FAQ

What is the minimum input voltage required for regulation at full 300 mA load?

The ZLDO330T8TA requires Vin ≥ Vout + 100 mV to maintain regulation at 300 mA, per datasheet dropout spec (max 200 mV). Thus, minimum valid input is 3.4 V. Below this, output collapses linearly with input; regulation is not guaranteed.

Can Pin 6 (D/C) be grounded to improve thermal performance?

No - Pin 6 is internally connected to a sensitive internal node and must remain unconnected. Grounding or biasing it causes instability, regulation loss, or permanent device damage. The SM8 package thermal path relies solely on soldered leads and PCB copper area.

How does the low-battery flag behave when input voltage recovers?

LBF releases (goes high-impedance) only after Vin rises ≥400 mV above Vout and remains there for >10 µs. Hysteresis prevents chatter during marginal input conditions. No external debounce is needed for clean interrupt assertion.

Is the ZLDO330T8TA RoHS-compliant and halogen-free?

Yes - Diodes Incorporated confirms ZLDO330T8TA (SM8 package) meets RoHS Directive 2011/65/EU and JEDEC JS709C halogen-free requirements. Lead finish is matte tin, and the mold compound is halogen-free per IEC 61249-2-21.