Diodes Incorporated ZSR500GTA

Overview

ZSR500GTA from Zetex plc is a fixed-output 5.0 V positive voltage regulator in SOT223 package, designed for local regulation in space-constrained PCBs. It delivers up to 200 mA output current, maintains ±2.5% initial output voltage tolerance (4.875–5.125 V), and operates across –55°C to +125°C with internal thermal shutdown and short-circuit current limiting - used in industrial sensor nodes and embedded microcontroller power rails.

For engineers reviewing the ZSR500GTA datasheet, ZSR500GTA pinout, ZSR500GTA application, or ZSR500GTA equivalent, key selection criteria include dropout voltage (≤0.3 V at 100 mA), quiescent current (350 µA typ.), ripple rejection (48–62 dB at 120 Hz), and stability without external capacitors.

Technical Context

The ZSR500GTA employs a monolithic bipolar linear regulator architecture with built-in current-limiting transistor and thermal foldback circuitry. Its feedback loop is internally compensated, enabling unconditional stability with zero external components across all load and input conditions.

It requires a minimum input voltage of 7.0 V to maintain regulation (V_IN – V_OUT ≥ 2.0 V), exhibits low output noise (75 µV_rms, 10 Hz–10 kHz), and achieves line regulation of ≤40 mV over 7–20 V input range and load regulation of ≤25 mV from 1–200 mA.

Key Specifications

Pinout & Package

SOT223-3 package (suffix G): thermally enhanced surface-mount outline with exposed thermal pad on underside; pin 2 is GND, pin 3 is V_OUT, pin 1 is V_IN; pin 4 is NC or tied to pin 2 per layout guidance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output linear regulator applications.

Compared with TLV755P50 and LD1117S50, the ZSR500GTA uniquely combines capacitor-free stability, wide temperature range, and robust fault protection - making it optimal for ruggedized, maintenance-free embedded systems where reliability trumps marginal IQ savings or current headroom.

Availability

ZSR500GTA is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body control modules, programmable logic controller I/O stages, and microcontroller local regulation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ZSR500GTA 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

Zetex plc (now part of Diodes Incorporated) was a UK-based analog semiconductor specialist focused on high-reliability discrete and linear ICs for industrial and automotive markets.

The ZSR Series was developed specifically for local voltage regulation in harsh environments - emphasizing fault resilience, wide operating temperature, and minimal external component count over raw efficiency or ultra-low IQ.

FAQ

Is the ZSR500GTA stable without an output capacitor?

Yes - the ZSR500GTA is internally compensated and fully stable with zero external capacitors. A 1 µF ceramic capacitor at the output is optional and improves transient response but is not required for stability per the datasheet's "No external components" feature and test conditions.

What is the maximum allowable input voltage for continuous operation?

The absolute maximum input voltage is 20 V, but continuous operation depends on power dissipation limits. At 25°C ambient, the SOT223 package supports 2 W; derating to zero at 125°C means max continuous input is ~12 V at 200 mA in still air without heatsinking - consult thermal resistance curves in Issue 3, page 6.

Does the ZSR500GTA support reverse-polarity input protection?

No - the device lacks integrated reverse-voltage protection. Applying reverse polarity to V_IN relative to GND may cause irreversible damage. An external series Schottky diode (e.g., 1N5819) is required if input reversal is possible in the system.

Can ZSR500GTA be used in parallel for higher current?

No - the ZSR500GTA is not designed for parallel operation. Its output voltage tolerance (±2.5%) and lack of current-sharing features mean paralleling units will cause unequal current distribution and potential thermal runaway. Use a single higher-current regulator instead.