SM-66T3 Fingerprint Module: High-Sensitivity Sensing, One-Touch Recognition

An Integrated Fingerprint Module for Multi-Scenario Applications

In applications such as identity authentication, access control and time-and-attendance, smart door locks, and self-service terminals, the stability of fingerprint recognition directly impacts device experience and operational efficiency. Addressing real-world requirements such as dry and wet fingers, shallow ridges, and worn prints, Miaxis introduces the SM-66T3, an integrated circular semiconductor fingerprint module. The module integrates a high-sensitivity sensor, a proprietary algorithm, template storage, and a communication interface within a compact design of 21 mm diameter and 6.2 mm thickness, delivering fast, stable, and integration-friendly fingerprint recognition.

Engineered In-House, Accessible to All

The SM-66T3 supports light-touch acquisition, rapid matching, and low-power standby, meeting the simultaneous demands that terminal products place on recognition performance, form factor, security, and development efficiency.

The circuit, firmware, and algorithm are all designed by Zhongzheng. The entire pipeline — from acquisition through 1:N search — runs on-module, accessed through a straightforward UART command set. Send a command. Get a result. That’s it.

High-Sensitivity Semiconductor Fingerprint Sensor for One-Touch Recognition

The SM-66T3 employs a high-sensitivity semiconductor fingerprint sensor. A light touch on the sensor surface initiates fingerprint acquisition and recognition. It supports adaptive acquisition parameter adjustment, optimizing imaging quality based on fingerprint state to improve image clarity and recognition stability. Compared with conventional modules that perform well only under ideal fingerprint conditions, the SM-66T3 accommodates a broader range of user demographics and operating environments. For example, it can handle dry or worn fingerprints from elderly users, moist fingers, and light-touch operation from children — reducing repeated pressing and recognition failures while improving throughput and device usability.

Self-Learning Algorithm and Encrypted Storage Design

Every successful match makes the next one better. The SM-66T3 features a built-in self-learning function: each verification updates the internal template, steadily improving recognition accuracy over time. Fingerprints that start as low-quality partials — faded, blurred, lightly pressed — become easier to match the more a user interacts with the device.

And the data behind that learning stays where it belongs. Fingerprint templates are stored in encrypted form inside the module. Raw biometric data never leaves the device — a design that meets the data-residency and privacy compliance requirements of banking, identity authentication, and government deployments without additional infrastructure.

Ultra-Low Power Design and Configurable Security Levels

The SM-66T3 supports a hardware sleep/wake interface with standby current of ≤6μA (typically 4.9μA). This power profile enables battery-powered smart locks, portable identity readers, and IoT endpoints to achieve extended operational lifetimes without frequent battery replacement or external power supply.

The module allows the security level to be customized per application scenario. At Security Level 3, the false accept rate is ≤0.001% and the false reject rate is ≤1.0%. This meets the certification requirements of banking and high-assurance access control, while also accommodating applications where throughput takes priority. Users can configure the module flexibly based on actual deployment requirements.

The SM-66T3 is suitable for access control and time-and-attendance, identity authentication terminals, banking and financial devices, smart door locks, and self-service terminals. Its 21mm circular footprint can be directly embedded into cylindrical housings and lock escutcheons without mechanical redesign.