Diodes Incorporated ZM33164CL

Overview

ZM33164CL from Zetex Semiconductors is a three-terminal under-voltage monitor IC designed for power-on reset and brownout detection in 5 V microprocessor systems. It features a fixed 4.3 V threshold with 60 mV hysteresis, open-collector output capable of sinking ≥10 mA, guaranteed operation from 1.0 V to 10 V supply, and internal clamp diode for delay capacitor discharge.

For engineers reviewing the ZM33164CL datasheet, ZM33164CL pinout, ZM33164CL application, or ZM33164CL equivalent, key selection criteria include precise 4.3 V trip point, low quiescent current (175–260 µA at 5 V), wide operating temperature range (−40 °C to +85 °C), TO-92/SOT-223 package options, and built-in hysteresis for noise immunity in noisy power rails.

Technical Context

The ZM33164CL integrates a precision voltage reference and comparator with internal hysteresis to eliminate oscillation during slow-rising or noisy supply transitions. Its output remains low from power-up until V_CC exceeds 4.33 V (typ.), then stays high until V_CC falls below 4.27 V (typ.), ensuring clean reset assertion.

Operation is guaranteed down to 1.0 V input, enabling reliable power-on reset generation even during weak battery start-up. The open-collector output interfaces directly with TTL/CMOS logic via a single pull-up resistor and supports sink currents up to 50 mA (max) with saturation voltage ≤0.46 V at 8 mA load.

Key Specifications

Pinout & Package

Available in TO-92 (suffix C) and SOT-223 (suffix G) packages. Pin configuration differs by package: TO-92 uses emitter-ground-collector layout; SOT-223 has pin 4 floating or tied to pin 2 (ground).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TLV803EB29DBZR, the ZM33164CL uniquely combines 4.3 V trip accuracy, integrated clamp diode for timing control, and dual-package availability-making it optimal for cost-sensitive, noise-prone 5 V microprocessor reset applications requiring minimal BOM count.

Availability

ZM33164CL is available at Aetrix Electronics and suitable for microprocessor power-on reset, automotive body electronics, portable instrumentation, and battery-powered peripherals requiring stable component supply across industrial temperature ranges and long product lifecycles.

Supply support for ZM33164CL 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 thermal efficiency in discrete and supervisory solutions.

The ZM33164CL belongs to Zetex's voltage supervisor product line, engineered specifically for robust, low-component-count reset generation in 5 V microprocessor systems operating under variable thermal and supply conditions.

FAQ

What is the exact threshold voltage tolerance of the ZM33164CL?

The ZM33164CL has a rising-threshold specification of 4.15 V (min) to 4.45 V (max) at 25 °C, with typical value 4.33 V. The falling-threshold range is 4.15 V to 4.45 V, typical 4.27 V. This yields 20–60 mV hysteresis, ensuring stable switching behavior across temperature and supply variations.

Can the ZM33164CL be used with a 3.3 V microprocessor?

No - the ZM33164CL is optimized for 5 V systems with a fixed 4.3 V threshold. Using it with 3.3 V logic risks premature or continuous reset assertion. For 3.3 V applications, consider alternatives like the TLV803 series with 3.08 V or 3.3 V thresholds and compatible output drive.

Does the ZM33164CL require an external capacitor for basic reset operation?

No external capacitor is required for fundamental under-voltage detection and reset assertion. However, a capacitor (C_d) is needed only when implementing time-delayed reset using the internal clamp diode; the device provides the discharge path, eliminating an external diode.

How does the open-collector output interface with modern logic families?

The open-collector output sinks current when active and requires an external pull-up resistor to V_CC or logic rail. It interfaces directly with TTL, CMOS, and mixed-voltage systems (e.g., 5 V OUT pulled to 3.3 V logic), supporting up to 50 mA sink current while maintaining ≤1.0 V saturation voltage at full load.