STMicroelectronics EVLALTAIR05T-5W

Overview

EVLALTAIR05T-5W from STMicroelectronics is an evaluation board for the ALTAIR05T-800 - a high-voltage, all-primary sensing, quasi-resonant flyback controller with integrated 800 V avalanche-rugged power MOSFET in SO16N package. It delivers constant voltage (CV) and constant current (CC) regulation without optocoupler, supports 85–265 VAC input, achieves ≤50 mW no-load consumption, and enables cable drop compensation for mobile charger applications.

For engineers reviewing the EVLALTAIR05T-5W datasheet, EVLALTAIR05T-5W pinout, EVLALTAIR05T-5W application, or EVLALTAIR05T-5W equivalent, this page provides verified board-level specifications, functional context, design-intent alignment with ALTAIR05T-800 IC operation, and sourcing support for AC-DC charger development targeting USB-C PD-compliant 5 W output.

Technical Context

The EVLALTAIR05T-5W implements a complete off-line quasi-resonant flyback reference design using the ALTAIR05T-800 IC, which integrates PWM controller and 800 V/1 A power switch. It operates across three dynamic modes: QR mode at full load (≤166 kHz), valley-skipping at medium load, and controlled burst-mode at light/no load to meet <50 mW standby requirements.

Primary-sensing feedback eliminates optocoupler and secondary-side references; ZCD/FB pin performs dual function - transformer demagnetization detection for valley switching and input voltage feedforward for mains-independent CC regulation. Cable drop compensation (CDC) is implemented via external resistor between CDC and ZCD/FB pins to maintain ±3% CV accuracy at output terminals under load.

Key Specifications

Availability

EVLALTAIR05T-5W is available at Aetrix Electronics and suitable for USB-C charger development, compact AC-DC adapter qualification, and primary-sensing SMPS validation requiring stable component supply, traceable evaluation hardware, and documented reference schematics.

Supply support for EVLALTAIR05T-5W 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 headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, analog devices, and silicon solutions for industrial, automotive, and consumer markets.

The ALTAIR series targets cost-sensitive, space-constrained AC-DC offline converters - specifically optimizing for optocoupler-free, low-standby, multi-mode flyback designs in mobile chargers and IoT power supplies.

FAQ

What is the purpose of the EVLALTAIR05T-5W evaluation board?

The EVLALTAIR05T-5W is a fully assembled, tested reference design board demonstrating the ALTAIR05T-800 IC in a 5 W quasi-resonant flyback configuration. It validates CV/CC regulation, cable drop compensation, and multi-mode operation - providing schematic, layout, BOM, and test reports to accelerate charger design without prototyping risk.

Does EVLALTAIR05T-5W require an auxiliary winding on the transformer?

Yes - the ALTAIR05T-800 IC requires an auxiliary winding to power its Vcc pin and provide ZCD/FB signal for demagnetization sensing. The EVLALTAIR05T-5W uses a custom 3-winding transformer (primary, secondary, auxiliary) with turns ratio optimized for 5 V output and self-supply stability across 85–265 VAC input.

Can EVLALTAIR05T-5W be modified for higher output power?

No - it is a fixed 5 W reference design. Output power is constrained by the ALTAIR05T-800's 1 A peak drain current rating, SO16N thermal limits (0.9 W Ptot @ 50 °C), and board-level magnetics/PCB layout. For >5 W, ST recommends ALTAIR06T-800 or VIPer series with higher current/power capability.

How is cable drop compensation implemented on this board?

Cable drop compensation is implemented by connecting a 47 kΩ resistor between the CDC pin (Pin 8) and ZCD/FB pin (Pin 6) of the ALTAIR05T-800. This creates a current-proportional offset that raises the CV regulation setpoint during load, counteracting voltage drop across the output cable - verified to maintain ≤±3% regulation at the USB connector under 1 A load.