Diodes Incorporated AZ7031ZTR-E1

Overview

AZ7031ZTR-E1 from BCD Semiconductor Manufacturing Limited is a precision under-voltage detector IC with 3.1 V detection threshold, open-collector output, and ±0.01 %/°C temperature coefficient. It monitors power supply rails in CPU reset circuits and battery-backed systems, delivering reliable reset assertion during power-on and brownout events with 50 mV built-in hysteresis and 0.8 V minimum operating voltage.

For engineers reviewing the AZ7031ZTR-E1 datasheet, AZ7031ZTR-E1 pinout, AZ7031ZTR-E1 application, or AZ7031ZTR-E1 equivalent, this device is selected for low-power, high-accuracy supply monitoring where stable reset timing, noise immunity, and operation down to 0.8 V are required in embedded control and portable electronics.

Technical Context

The AZ7031ZTR-E1 uses an on-chip precision voltage reference and comparator to compare VCC against a fixed 3.1 V threshold (VDET− = 2.95 V typical, VDET+ = 3.25 V typical), enabling accurate power-fail detection across −40 °C to +85 °C. Its open-collector output requires external pull-up and sinks up to 20 mA at VCC ≥ VDET(min) − 0.05 V.

Reset assertion is timed by propagation delays: tpHL = 10 µs (falling edge), tpLH = 15 µs (rising edge), measured with RL = 1 kΩ and CL = 100 pF. The device remains functional down to 0.8 V supply, ensuring valid output behavior during deep brownouts before full power collapse.

Key Specifications

Pinout & Package

AZ7031ZTR-E1 is packaged in SOT-89 (3-pin, surface-mount), with pin 1 = VCC, pin 2 = GND, pin 3 = OUT. This thermally enhanced package supports 500 mW power dissipation at TA = 25 °C and features θJC = 74 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TC709RTR and MAX809STR, AZ7031ZTR-E1 trades slightly higher quiescent current for guaranteed 0.8 V operation, 50 mV hysteresis, and robust 20 mA sink drive-making it optimal for cost-sensitive industrial designs requiring wide supply tolerance and noise margin.

Availability

AZ7031ZTR-E1 is available at Aetrix Electronics and suitable for CPU reset generation, battery voltage monitoring, power fail indication, and backup power control requiring stable component supply across industrial, consumer, and embedded production programs.

Supply support for AZ7031ZTR-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 partner, specializing in high-reliability power management and sensing solutions for industrial and consumer markets.

AZ7031ZTR-E1 belongs to the AZ70XX series of voltage detectors, engineered for accurate, low-power supply monitoring in resource-constrained embedded systems where predictable reset behavior and thermal stability are critical.

FAQ

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

For standard 3.3 V or 5 V logic interfaces, a 10 kΩ pull-up resistor provides optimal rise time and current consumption balance. At 5 V, this yields ~0.5 mA standby current and <100 ns rise time with ≤50 pF load capacitance. Lower values (e.g., 4.7 kΩ) improve noise immunity in electrically noisy environments but increase static power draw.

Does AZ7031ZTR-E1 require an external capacitor on the VCC pin?

Yes - a 10 µF tantalum or ceramic capacitor placed within 5 mm of the VCC and GND pins is mandatory per the datasheet's Figure 14. This stabilizes the internal reference and prevents false triggering during fast transients. Omitting it degrades hysteresis performance and may cause erratic reset pulses under load switching.

Can AZ7031ZTR-E1 operate with a 24 V input supply?

No - the absolute maximum VCC rating is 20 V. Applying 24 V exceeds the Absolute Maximum Ratings and risks permanent damage. For 24 V systems, use a resistive divider or LDO pre-regulator to deliver ≤18 V to the AZ7031ZTR-E1 VCC pin while maintaining noise immunity and accuracy.

How does temperature affect the 3.1 V detection threshold?

The detect voltage drifts ±0.01 %/°C relative to nominal value, resulting in ±0.31 V total shift over −40 °C to +85 °C. At −40 °C, VDET− ≈ 2.98 V; at +85 °C, VDET− ≈ 3.07 V. This is confirmed in Figure 7 of the datasheet and remains within the specified 2.95–3.25 V window.