Diodes Incorporated AZ7042RTR-E1

Overview

AZ7042RTR-E1 from BCD Semiconductor Manufacturing Limited is a precision voltage detector IC with 4.2 V detection threshold, open-collector output, and built-in 50 mV hysteresis-designed for reliable power-on reset and brown-out monitoring in microcontroller-based systems. It operates from 0.8 V minimum supply, consumes only 30 µA typical quiescent current at V_CC = 5.25 V, and functions across –40 °C to +85 °C for industrial-grade embedded applications.

For engineers reviewing the AZ7042RTR-E1 datasheet, AZ7042RTR-E1 pinout, AZ7042RTR-E1 application, or AZ7042RTR-E1 equivalent, this device serves as a low-power, temperature-stable reset supervisor for CPU systems requiring accurate 4.2 V supply monitoring, fast response to voltage transients (tp_LH = 15 µs), and robust noise immunity via internal hysteresis.

Technical Context

The AZ7042RTR-E1 integrates a precision on-chip voltage reference and comparator to monitor V_CC against a fixed 4.2 V threshold (V_DET− = 4.05–4.35 V). Its open-collector output pulls low when V_CC falls below V_DET−, with release occurring at V_DET+ = V_DET− + V_HYS (typ. 4.25 V) to prevent chatter near threshold.

It features a minimum operating voltage of 0.8 V (typ.), enabling valid output behavior down to ultra-low supply levels, and supports load currents up to 16 mA over full temperature range while maintaining V_OL ≤ 0.4 V at R_L = 200 Ω.

Key Specifications

Pinout & Package

The AZ7042RTR-E1 is housed in a SOT-89 surface-mount package (4.4 × 4.6 × 1.1 mm), optimized for thermal performance (θ_JC = 74 °C/W) and board space efficiency in compact power management layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV803EB42DBZR and MAX809SEUR+T, the AZ7042RTR-E1 offers superior temperature stability (±0.01 %/°C), integrated hysteresis eliminating external components, and higher output drive (16 mA) - making it optimal for industrial environments where thermal variation and noise immunity are prioritized over minimal quiescent current.

Availability

AZ7042RTR-E1 is available at Aetrix Electronics and suitable for low-battery detection, processor reset generation, and power-fail indication requiring stable component supply across automotive infotainment modules, industrial PLC I/O cards, and medical wearable monitors.

Supply support for AZ7042RTR-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 and foundry, specializing in high-reliability power management and interface solutions for industrial and consumer markets.

The AZ70XX series belongs to BCD's precision supervisory IC product line, engineered specifically for accurate, low-power voltage monitoring in resource-constrained embedded systems where reset integrity and thermal stability are critical.

FAQ

What is the recommended pull-up resistor value for the AZ7042RTR-E1 open-collector output?

A 10 kΩ pull-up resistor to 3.3 V or 5 V is recommended for most applications, balancing speed (tp_LH < 15 µs), power consumption (< 0.5 mW), and noise immunity. Lower values (e.g., 4.7 kΩ) improve rise time but increase static current; higher values (> 100 kΩ) risk slow edges and EMI susceptibility in noisy environments.

Can the AZ7042RTR-E1 operate from a 3.3 V supply while monitoring a separate 4.2 V rail?

No - the AZ7042RTR-E1 monitors its own V_CC pin; it cannot sense an independent voltage rail. To monitor a 4.2 V supply while powered from 3.3 V, a resistive divider or dedicated high-voltage detector like the AZ7042ZTR-E1 (TO-92 variant) with appropriate scaling would be required.

Does the AZ7042RTR-E1 require an external capacitor on the VCC pin?

No external bypass capacitor is mandatory per datasheet, but a 1 µF ceramic capacitor placed within 5 mm of the V_CC and GND pins is strongly recommended to suppress high-frequency noise and ensure stable detection during transient load changes on the monitored rail.

How does hysteresis affect the reset release point for AZ7042RTR-E1?

Hysteresis raises the release voltage to V_DET+ = V_DET− + V_HYS ≈ 4.25 V (typ.), meaning the output remains low until V_CC rises above ~4.25 V after falling below 4.2 V. This prevents oscillation during slow-rising supplies or noisy conditions near the threshold.