Diodes Incorporated AZ7042Z-E1

Overview

AZ7042Z-E1 from BCD Semiconductor Manufacturing Limited is a precision under-voltage detector IC with 4.2 V detection threshold, open-collector output, and -40°C to +85°C operating range. It monitors power supply rails in microcontroller-based systems, delivers reset signals during brown-out events, consumes only 30 µA typical quiescent current at V_CC = 5.25 V, and operates down to 0.8 V minimum supply voltage - enabling reliable reset generation even during deep discharge or low-V_CC startup sequences.

For engineers reviewing the AZ7042Z-E1 datasheet, AZ7042Z-E1 pinout, AZ7042Z-E1 application, or AZ7042Z-E1 equivalent, this device is selected for battery-backed system supervision, CPU reset timing control, low-power sensor node voltage monitoring, and industrial embedded power-fail detection where hysteresis-stabilized threshold accuracy and TO-92 package compatibility are critical.

Technical Context

The AZ7042Z-E1 implements a precision bandgap reference and comparator architecture to detect falling V_CC below 4.2 V (±0.15 V) and release above 4.25 V (V_HYS = 50 mV typical), ensuring noise-immune operation in noisy power environments. Its open-collector output interfaces directly with TTL/CMOS logic and supports external pull-up to any rail up to 18 V.

It operates across full industrial temperature range (-40°C to +85°C) with ±0.01 %/°C detect voltage drift, and maintains valid output state between 0.8 V and 18 V supply - supporting both pre-regulator monitoring and post-LDO supervision in multi-rail systems.

Key Specifications

Pinout & Package

AZ7042Z-E1 is supplied in TO-92 bulk packaging (3-pin, straight lead). Pin 1 = Output (open-collector), Pin 2 = Ground, Pin 3 = V_CC. The package supports through-hole mounting and meets RoHS-compliant lead-free requirements per "E1" suffix.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV803EB42DBZR and MAX809SEUR+T, AZ7042Z-E1 delivers true threshold-hysteresis detection in TO-92 with zero external components, making it optimal for cost-sensitive, noise-prone, through-hole designs requiring deterministic reset behavior without timing delays or added passive parts.

Availability

AZ7042Z-E1 is available at Aetrix Electronics and suitable for industrial control panels, battery-powered IoT sensors, consumer appliance power supervisors, and embedded reset circuits requiring stable component supply with RoHS-compliant lead-free construction.

Supply support for AZ7042Z-E1 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

BCD Semiconductor Manufacturing Limited is a Shanghai-based analog and mixed-signal IC designer specializing in power management, protection, and supervisory devices for industrial, automotive, and consumer markets.

The AZ70XX series was developed to deliver low-cost, high-accuracy voltage monitoring in legacy-compatible TO-92 and SOT-89 packages - targeting cost-sensitive embedded systems needing reliable reset and brown-out protection without complex external circuitry.

FAQ

What is the recommended pull-up resistor value for the open-collector output?

A 10 kΩ to 100 kΩ resistor to the target logic rail (e.g., 3.3 V or 5 V) is recommended. Lower values reduce rise time but increase static current; higher values improve efficiency but may degrade noise immunity. For 5 V systems with 20 mA sink capability, 4.7 kΩ ensures robust low-level drive while maintaining <1 mA total current draw.

Can AZ7042Z-E1 monitor a 3.3 V rail?

No - AZ7042Z-E1 is factory-trimmed to 4.2 V detection and cannot be adjusted. For 3.3 V monitoring, use AZ7033Z-E1 (3.3 V variant). Using AZ7042Z-E1 on a 3.3 V rail would result in permanent output assertion since V_CC never reaches the 4.2 V threshold.

Does AZ7042Z-E1 require an external capacitor on the output?

No external capacitor is required for basic operation. However, a 100 pF capacitor from OUT to GND may be added to suppress high-frequency ringing in long PCB traces. This does not affect detection timing but improves EMI resilience in motor-driven or switching-power environments.

Is AZ7042Z-E1 compatible with lead-free reflow soldering profiles?

Yes - the "E1" suffix confirms RoHS compliance and qualification for standard lead-free reflow (J-STD-020, peak 260°C). TO-92 package thermal mass allows safe processing in convection or vapor-phase ovens without die damage or bond wire lift.