Diodes Incorporated ZM33064CSTZ

Overview

ZM33064CSTZ from Zetex Semiconductors is a three-terminal under-voltage monitor IC for microprocessor power-on reset and supply supervision in 5 V systems, featuring a fixed 4.6 V threshold, 20 mV hysteresis, open-collector output capable of sinking ≥10 mA, and guaranteed operation from 1.0 V to 6.5 V supply.

For engineers reviewing the ZM33064CSTZ datasheet, ZM33064CSTZ pinout, ZM33064CSTZ application, or ZM33064CSTZ equivalent, key selection factors include its precise 4.6 V trip point, built-in hysteresis for noise immunity, low quiescent current (200 µA at 5 V), TO-92 through-hole package compatibility, and integrated clamp diode for reset delay capacitor discharge.

Technical Context

The ZM33064CSTZ integrates a precision voltage reference and comparator with internal hysteresis to ensure stable threshold detection across temperature (±0.05 V variation from −40 °C to +85 °C). Its open-collector output stage supports direct interface to TTL/CMOS logic via a single pull-up resistor.

Operation begins at 1.0 V supply, holding output low until V_CC exceeds 4.61 V (rising edge); falling supply below 4.59 V reasserts reset. Propagation delay is 1.5 µs under standard test conditions (R_L = 10 kΩ, T_AMB = 25 °C).

Key Specifications

Pinout & Package

Package: TO-92 (suffix C), through-hole mounting, 3-pin plastic case with standard lead configuration.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar under-voltage monitor applications.

Compared with MAX809SCSA+ and TL7705ACD, ZM33064CSTZ uniquely combines TO-92 through-hole compatibility, integrated clamp diode for simplified RC delay, and robust 10 mA sink drive-making it optimal for cost-sensitive, serviceable, or legacy-replacement designs requiring minimal BOM count.

Availability

ZM33064CSTZ is available at Aetrix Electronics and suitable for microprocessor power-on reset, industrial control PLCs, and automotive body control modules requiring stable component supply with long-term manufacturability and through-hole assembly support.

Supply support for ZM33064CSTZ 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 Semiconductors (now part of Diodes Incorporated) specialized in high-performance analog and power management ICs, emphasizing precision, reliability, and ease-of-use in industrial and automotive applications.

The ZM33064 series was designed specifically for simple, robust power-supply monitoring in 5 V microprocessor systems-prioritizing fixed-threshold accuracy, hysteresis stability, and minimal external components.

FAQ

What is the function of the internal clamp diode in ZM33064CSTZ?

The internal clamp diode connects between V_IN and the OUT pin. During power-down, it discharges an external RC timing capacitor used for reset delay, ensuring monotonic reset timing and eliminating need for a discrete diode. It conducts at ~1.2 V forward drop with 10 mA current, enabling predictable discharge behavior across temperature.

Can ZM33064CSTZ operate reliably below 5 V supply?

Yes-ZM33064CSTZ is fully specified from 1.0 V to 6.5 V. At 1.0 V input, it holds the open-collector output low, providing power-on reset assertion even during slow-ramp or battery-depleted conditions. Its internal reference and comparator remain functional down to 1 V, enabling use in ultra-low-voltage supervisory roles.

How does the 20 mV hysteresis improve system reliability?

The 20 mV hysteresis creates a 4.59 V lower threshold (falling) versus 4.61 V upper threshold (rising), forming a 20 mV window. This prevents output chatter during supply fluctuations near the trip point-such as ripple, noise, or gradual brown-out-ensuring each reset assertion/deassertion is clean, single-event, and immune to false triggering.

Is ZM33064CSTZ pin-compatible with other ZM33064 package variants?

Yes-ZM33064C (TO-92), ZM33064N8 (SO-8), and ZM33064G (SOT-223) share identical pinout: Pin 1 = V_IN, Pin 2 = GND, Pin 3 = OUT. The TO-92 variant maintains full electrical compatibility, allowing direct substitution in through-hole designs without schematic or layout changes.