EVHR1231-S-00A

The EVHR1231-S-00A evaluation board is designed to demonstrate the capabilities of the HR1231, HR1232, and LTA2601. The HR1231 is a high-performance, multi-mode power factor correction (PFC) and current-mode LLC digital combo controller. The device’s parameters are configurable via the FBL/UART interface, which provides convenient customization. Power-saving technology helps the power supply design achieve overall optimized efficiency.

The HR1231’s PFC control employs a patented extended multi-mode (EMM) control scheme to achieve hybrid continuous conduction mode (CCM), critical conduction mode (CrM), and discontinuous conduction mode (DCM), which optimizes efficiency across all load conditions. The operating mode is automatically determined according to the real-time input current. The HR1231 can also achieve stable output regulation under critical surge load conditions by instantaneous response. The device’s power factor (PF) compensation helps the power supply to easily meet regulation requirements.

The HR1231 implements current mode control in the LLC stage, allowing the device to simultaneously achieve good stability and fast response. In addition, three different modes are implemented based on the load conditions: continuous mode, skip mode, and burst mode. As a result, efficiency under different load conditions can be optimized independently. The LLC converter’s key zero-voltage switching (ZVS) feature benefits efficiency performance the most, and can always be guaranteed by the adaptive dead time (DT) of the high-side (HS) gate driver and low-side (LS) gate driver. Any capacitive operation is also effectively prevented in the HR1231.

The HR1231 integrates a high-voltage (HV) current source for start-up. The HV current source is also implemented as the X-capacitor discharger during AC input dropout, meaning that the resistor for the X-capacitor discharger can be removed as well.

The HR1231 features variable protections for system safety in the event of any faults. These protections include thermal shutdown (TSD), external over-temperature protection (OTP), PFC open-loop protection (OLP), PFC over-voltage protection (OVP), PFC over-current limit (OCL), LLC over-current protection (OCP), LLC over-power protection (OPP), and external protection.

The EVHR1231-S-00A’s input voltage (V_IN) range is 90V_AC to 265V_AC. The evaluation board’s full-load efficiency is about 94.09% at 115V_AC and 95.38% at 230V_AC.

The total no-load power loss is <65mW at 230V_AC. X-capacitors contribute a large portion of no-load power loss. The total no-load power loss of this board can be below 60mW, using low-loss X-capacitors (e.g. BFC233922474).

The EVHR1231-S-00A’s PFC controller can work in CrM and DCM multi-mode, with high efficiency across the full-load range. It can run at the highest switching frequency (f_SW) of 250kHz, with a high PF due to the input capacitor’s current compensation.

The EVHR1231-S-00A’s LLC controller utilizes current mode control. The HR1231 features skip mode for good light-load efficiency. The HR1231 has a built-in 600V HS gate driver with high dV/dt immunity, and has adaptive dead-time adjustment (ADTA) with a minimum and maximum DT limit.

The EVHR1231-S-00A’s peak power function can operate at a peak power of 600W, for up to 50ms within a 500ms period. Exceeding this condition may cause the device to overheat. All subsequent tests related to the peak power function are tested for a limited time period, and not for continuous operation.

The EVHR1231-S-00A is designed as a notebook adapter. It can be used to evaluate the HR1231’s applications, including applications with a similar output voltage (V_OUT). For more details, refer to the HR1231 datasheet.