Diodes Incorporated ZR285R03STZ

Overview

ZR285R03STZ from Diodes Incorporated is a precision 2.5 V micropower voltage reference IC using bandgap circuit design, with ±2% initial tolerance, 30 ppm/°C typical temperature coefficient, and stable operation from 20 µA to 20 mA supply current. It operates across –40°C to +85°C and requires no external stabilization capacitor, making it suitable for battery-powered instrumentation and portable data acquisition systems.

For engineers reviewing the ZR285R03STZ datasheet, ZR285R03STZ pinout, ZR285R03STZ application, or ZR285R03STZ equivalent, key selection criteria include knee current (15 µA typ), slope resistance (0.4 Ω typ), reverse dynamic impedance (0.3–0.8 Ω), wideband noise (60 µV_rms), and SOT23-3 package compatibility in space-constrained designs.

Technical Context

The ZR285R03STZ functions as a two-terminal shunt-mode voltage reference, sinking current to maintain a precise 2.5 V reverse breakdown voltage across its cathode-anode terminals. Its bandgap core delivers low drift and high stability without external compensation components.

It exhibits low dynamic impedance (0.3–0.8 Ω at 1 mA, 100 Hz) and fast turn-on settling (<5 µs), enabling use in low-power ADC biasing and precision regulator feedback paths where load transients and supply ripple rejection are critical.

Key Specifications

Pinout & Package

Package: SOT23-3 (JEDEC TO-236AB), 2.80 × 2.64 × 1.12 mm body, 0.95 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt voltage reference applications.

Compared with TLVH431AIDBZR and LM4040C25IDBZR, ZR285R03STZ uniquely balances ultra-low knee current (15 µA), low noise (60 µV_rms), and fixed 2.5 V output in SOT23-3 - making it optimal for battery life–critical, space-constrained instrumentation where trimming and adjustability are unnecessary.

Availability

ZR285R03STZ is available at Aetrix Electronics and suitable for battery-powered portable meters, precision data acquisition front-ends, and calibrated test & measurement equipment requiring stable component supply and long-term parametric consistency.

Supply support for ZR285R03STZ 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, cost-optimized components for industrial, computing, and consumer markets.

The ZR285 series belongs to Diodes' precision voltage reference product line, engineered specifically for micropower, fixed-output shunt references in portable and measurement-critical applications where size, stability, and low I_Q are primary constraints.

FAQ

What is the maximum capacitive load the ZR285R03STZ can drive without instability?

ZR285R03STZ is internally compensated and stable with any capacitive load up to 10 µF, as confirmed by Diodes' DS32168 Rev. 8-2 characterization. No external capacitor is required for stability, and phase margin remains >45° even with 1 µF ceramic output capacitance, enabling direct use with ADC sample-and-hold inputs or LDO feedback nodes.

Can ZR285R03STZ be used in series with a current-limiting resistor for 3.3 V supply rails?

Yes - ZR285R03STZ is designed for shunt operation with a series resistor. For a 3.3 V rail, a 390 Ω resistor limits current to ~2.05 mA at 2.5 V drop, well within the 20 µA–20 mA recommended range. This configuration provides stable 2.5 V reference while dissipating only ~5.1 mW in the device itself.

Does ZR285R03STZ require PCB layout precautions for thermal drift?

Yes - thermal coupling between the SOT23-3 anode pad and adjacent copper pours directly affects temperature coefficient. Diodes recommends isolating the anode (Pin 2) with narrow traces and minimizing copper area beneath the package. Layouts achieving <0.5°C/W junction-to-ambient thermal resistance show <5 ppm/°C additional drift beyond specified 30 ppm/°C.

Is ZR285R03STZ qualified for automotive applications?

No - ZR285R03STZ is specified for industrial temperature range (–40°C to +85°C) and is not AEC-Q200 qualified. While it meets functional specs in automotive ambient conditions, Diodes does not guarantee performance under automotive qualification stress tests (e.g., temperature cycling, humidity bias, mechanical shock), and no PPAP documentation is available for this part number.