1 KW Car Charging Solution with Digital Power Factor Controller

he EVLSTRNG-1KW board is used to evaluate STNRG388A digital controllers in offline power conversion applications such as EV battery chargers, UPS and industrial power supplies. The architecture is based on a multi-phase interleaved DC / DC converter using a half-bridge SAB ("Single Active Bridge") single active bridge topology, which can support more than 1000 W of power.

The staggered topology balances power through three parallel stages. In addition, the solution provides high efficiency across the entire load range by enabling one, two or three stages depending on the load. The STNRG388A power conversion-specific peripheral state machine event drive (SMED) provides the flexibility to drive interleaved power stages while ensuring correct phase realignment when starting and stopping each stage. With STNRG388A's digital core, the EVLSTRNG-1KW board can also be monitored, controlled, and debugged through convenient HyperTerminal control.

The circuit board consists of two parts:

1. 3 W flyback topology auxiliary power supply based on Viper06H high voltage switch. Used for offline applications. This auxiliary converter provides 15 V / 0.1 A to the primary side, powers the driver and control logic, and provides ± 7.5 V / 0.1 A power supply analog feedback compensation on the secondary side.

2. The main converter consists of three SAB (Single Active Bridge) converters, which control the STNRG388A digital controller, which can manage the output power by changing the switching frequency and switching image position. The L6391 drives separate MOSFETs for the main converter. This dedicated accessory driver also integrates an intelligent shutdown function and an internal analog comparator to quickly trigger several protection functions. The accurate reference voltage reduces the auxiliary supply voltage, which provides the STNRG388A with 30 mA at 3.3 V.

Scene application diagram

Product entity diagram

Solution block diagram

Application architecture

Core technology advantages

Can help designers maximize the advantages of digital power conversion technology, including energy-efficient performance at full load, higher safety, and rich diagnostic capabilities!

STMicroelectronics' unique high-resolution pulse-width modulation (PWM) signal generator for State Machine Event Driven (SMED), and ordinary digital signal processors or microcontroller-based Unlike CNC solutions, STNRG can directly trigger the SMED controller by internal timers or external events, such as peak current, excess current or voltage zero crossing, the peak current is detected by a buck converter, and the constant off time is set by the timer. No need to intervene in other core processors. In addition, a simple proportional-integral (P-I) cycle performed by the kernel sets the peak current value for the output regulation circuit.

Solution specifications

• Input voltage range: 350-420 Vdc

• Full load power: 1000 W

• CC / CV output adjustment

• Output voltage regulation: 133 V ± 2.5%

• Output current regulation: 7.5 A ± 5%

• Minimum output current per phase without burst mode: 1A

• Maximum output current per phase: 2.5 A

• Interleaving architecture

• No-load standby power consumption: 425 mW

• Efficiency: from 1% to full load, more than 90%

• Peak efficiency: 96.5% at full load

• Safety: Compliant with EN60950

• Power board size: 20.7x16.5 mm, the maximum component height from the PCB is 50 mm

• Control board size: 6.9x5 mm, vertical installation

• Power board PCB: double layer, 35μm, hybrid PTH / SMT

• Control board PCB: double layer, 35μm, mixed PTH / SMT

• Configurable system via UART I / F

• Status LED for protection function and active phase

Technical Documents

Power Test Report

Datasheet

BOM