STMicroelectronics STM1403ATOQ6F

Overview

STM1403ATOQ6F from STMicroelectronics is a FIPS-140 Level 3+ security supervisor IC designed for tamper-evident cryptographic modules in POS terminals and secure payment devices. It provides four high-impedance physical tamper inputs (TP1–TP4), over/under voltage detection (2.0 V / 4.2 V thresholds), automatic battery switchover at ~2.4 V, open-drain SAL/RST/PFO/BLD outputs, and low quiescent current (2.8 µA typ). Its VOUT pin remains ON during security alarm assertion - a key behavior of the STM1403A variant.

For engineers reviewing the STM1403ATOQ6F datasheet, STM1403ATOQ6F pinout, STM1403ATOQ6F application, or STM1403ATOQ6F equivalent, this page delivers verified circuit role, tamper response timing, battery switchover behavior, VREF availability (1.237 V), and QFN16 package integration details required for secure embedded system design and FIPS compliance validation.

Technical Context

The STM1403ATOQ6F implements dual-voltage monitoring with independent VCC/VBAT comparators, enabling robust power-fail detection (PFI threshold ~2.4 V) and battery low detection (VBAT < 2.3–3.2 V, customer-selectable). Its tamper detection logic monitors four dedicated pins (TP1–TP4) with configurable NH/NL biasing and triggers SAL on any state inversion - supporting both switch-open and switch-closed intrusion sensing topologies.

During battery switchover, VOUT transitions from VCC to VBAT with controlled on-resistance (<1.5 Ω typical), while Vccsw asserts high to indicate backup mode. The RST output features 200 ms reset timeout (trec) after VCC recovery, and all open-drain outputs (SAL, RST, PFO, BLD) support wired-OR interfacing with external microcontrollers or NMI lines.

Key Specifications

Pinout & Package

STM1403ATOQ6F uses a secure low-profile 16-pin QFN package (3 mm × 3 mm, 0.5 mm pitch), optimized for tamper-resistant PCB layout with exposed thermal pad grounded to VSS.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar security supervisor applications.

Compared with MAX6956ETJ+ and DS1233M-5+, STM1403ATOQ6F uniquely integrates FIPS-140 Level 3+ tamper response, autonomous VCC/VBAT switchover, and SAL-driven crypto erasure signaling - making it irreplaceable in certified payment and banking hardware where regulatory compliance is non-negotiable.

Availability

STM1403ATOQ6F is available at Aetrix Electronics and suitable for POS terminal security modules, EMVCo-compliant payment devices, and banking ATM cryptographic modules requiring stable component supply and long-term lifecycle support.

Supply support for STM1403ATOQ6F 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

STMicroelectronics is a global semiconductor leader specializing in secure microcontrollers, power management, and analog/mixed-signal ICs for industrial, automotive, and smart-card applications.

The STM1403 family was developed specifically for FIPS-140-2 Level 3+ cryptographic module manufacturers, delivering certified tamper detection, battery-backed power management, and secure alarm signaling in a compact QFN package.

FAQ

What is the function of the VREF pin on STM1403ATOQ6F?

The VREF pin outputs a precise 1.237 V (typ) reference voltage, available exclusively on the STM1403A variant. It operates only when VCC is between 2.4 V and 3.6 V; below 2.4 V, it is internally pulled to ground via a 100 kΩ resistor. This pin supports external ADC calibration or comparator biasing in secure subsystems requiring stable analog references.

How does STM1403ATOQ6F behave during a physical tamper event?

Upon detection of any tamper condition - including state inversion on TP1–TP4, VCC < 2.0 V, or VCC > 4.2 V - the SAL output immediately asserts low (open drain). For the STM1403A variant, VOUT remains powered (ON), while Vccsw reflects the current source (low = VCC, high = VBAT). This behavior ensures continuous power to crypto memory while signaling intrusion to the host processor.

Can STM1403ATOQ6F support different battery low voltage thresholds?

Yes - the BLD output activates during power-up when VBAT falls below a customer-selectable VDET threshold: 2.3 V (for 3 V Li cells with diode drop), 2.5 V (same cell, alternate configuration), or 3.2 V (for 3.68 V "AA" lithium batteries). This selection is implemented externally via resistor network on the BLD pin per datasheet Figure 11, enabling precise battery health validation across chemistries.

What is the significance of the QFN16 package for security applications?

The 3 mm × 3 mm QFN16 package features an exposed thermal pad tied to VSS, enabling low-inductance grounding critical for noise-immune tamper signal routing. Its compact size and leadless construction resist mechanical probing and simplify conformal coating - directly supporting FIPS-140 Level 3 physical security requirements for conductive trace detection and environmental monitoring.