STMicroelectronics STEVAL-VP319X1B

Overview

STEVAL-VP319X1B from STMicroelectronics is an evaluation board implementing a non-isolated 5 V / 0.6 A (3 W) buck converter based on the VIPER319X offline high-voltage controller IC, operating from universal AC input (85–265 VAC, 50–60 Hz), achieving >69.7% average efficiency at full load and <16 mW no-load power consumption at 230 VAC, designed for auxiliary power supply in industrial and consumer electronics.

For engineers reviewing the STEVAL-VP319X1B datasheet, STEVAL-VP319X1B schematic, STEVAL-VP319X1B application, or STEVAL-VP319X1B equivalent, key selection factors include its 30 kHz fixed-frequency jittered PWM control, burst-mode light-load management, IEC55022 Class B EMI compliance, RoHS status, and support for extended 40–265 VAC input when bulk capacitance is increased.

Technical Context

The board implements a primary-side-controlled, non-isolated buck topology using the VIPER319X - an integrated offline converter with 800 V avalanche-rugged Power MOSFET, current-mode PWM control, and fixed 30 kHz switching frequency with spread-spectrum jittering to reduce EMI peaks. It operates without optocoupler feedback, relying on auxiliary winding sensing for regulation.

Burst mode enables dynamic switching cycle skipping below ~10% load, reducing standby power to <16 mW at 230 VAC. Input rectification is via bridge DB4296-referenced discrete diodes; output filtering uses L2 and C6/C5; OVP/UVP protection is implemented via FB and UVP pins tied to external resistor dividers.

Key Specifications

Availability

STEVAL-VP319X1B is available at Aetrix Electronics and suitable for auxiliary power supply design, energy-efficient AC/DC conversion validation, and VIPER319X-based buck topology prototyping requiring stable component supply and reference-grade implementation fidelity.

Supply support for STEVAL-VP319X1B 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, designing and manufacturing microcontrollers, power ICs, analog chips, and MEMS sensors for industrial, automotive, and consumer applications.

The STEVAL-VP319X1B belongs to ST's VIPERPlus evaluation platform series, developed to accelerate adoption of high-voltage offline converters for compact, low-BOM-count auxiliary supplies up to 20 W in space-constrained systems.

FAQ

Is STEVAL-VP319X1B isolated or non-isolated?

STEVAL-VP319X1B implements a non-isolated buck converter topology. There is no transformer isolation between input and output; the output shares ground with the input DC bus after rectification. This design targets cost-sensitive, space-limited auxiliary rails where galvanic isolation is not required.

What is the role of the VIPER319X IC on this board?

The VIPER319X serves as the integrated offline controller and 800 V Power MOSFET, providing current-mode PWM control at 30 kHz with jittering, burst-mode operation for light loads, and built-in protections including OVP, UVP, and thermal shutdown - eliminating need for external gate drivers or sense resistors.

Can STEVAL-VP319X1B operate below 85 VAC?

Yes - with increased input bulk capacitor value (e.g., ≥47 µF), the board supports extended input range down to 40 VAC while maintaining 5 V/0.6 A output, enabling compatibility with brownout-prone or wide-range industrial AC sources.

Does this board include EMI filtering components?

Yes - it integrates a π-filter (C1, L1, C2) at the AC input and output LC filtering (L2, C5, C6) to meet IEC55022 Class B conducted emissions limits without requiring external filters, verified per DB4296 test reports.