STEVAL-ISA176V1 STMicroelectronics

S T E VA L - I S A 1 7 6 V 1 ALTAIR05T-800 5 W wide range CV-CC optoless adapter evaluation board Data brief The core of the application is the ALTAIR05T- 800, the first all-primary sensing switching regulator of the ALTAIR family. The IC combines a high-performance, low- voltage PWM controller chip and an 800 V, avalanche-rugged power MOSFET in the same package. The PWM chip is a quasi-resonant (QR) current mode controller IC specifically designed for QR ZVS (zero voltage switching at switch turn-on) flyback converters. The device is capable of providing constant output voltage (CV) and constant output current (CC) regulation using primary-sensing feedback. This eliminates the need for the optocoupler, the Features secondary voltage reference and the current Universal input mains range: 90 - 264 V AC, sensor, while still maintaining quite accurate frequency 45-65 Hz regulation. Output voltage: 5 V 1 A continuous operation In addition, it is possible to compensate the voltage drop on the output cable to improve CV Optoless constant voltage - constant current regulation on the externally accessible terminals. output regulation Standby mains consumption: < 100 mW Extremely low consumption under no load 230 V AC conditions is ensured thanks to controlled burst Average efficiency: >70% mode operation that, along with the built-in high EMI: in accordance with EN55022-Class-B voltage startup circuit and the low operating RoHS compliant current of the device, helps minimize the residual input consumption. Although an auxiliary winding is required in the transformer to correctly perform Description CV/CC regulation, the chip can be powered The STEVAL-ISA176V1 evaluation board directly from the rectified mains. This is useful implements a 5 W (5 V / 1 A) wide-range mains particularly during CC regulation, where the battery charger with constant voltage/constant flyback voltage is generated by the winding current, tailored for AC-DC chargers for mobile drops. phones and adapters or other hand-held equipment. October 2015 DocID028457 Rev 1 1/5 www.st.com For further information contact your local STMicroelectronics sales office Schematic diagram STEVAL-ISA176V1 1 Schematic diagram Figure 1: EVLALTAIR05T-5W circuit schematic GSPG0710151050SG 2/5 DocID028457 Rev 1 D7 5V - 1A L1 T1 470uH BR STPS3L40UF MB6S-RC AC IN R1 C3 R2 C1 C2 1nF 120K C8 22 4.7uF 4.7uF R9 1000uF 1W 400V 400V 1.3k Low ESR AC IN D7 STTH1L06 R3 GND 30K D2 R4 C9 BAT46 0 100nF C4 10uF R5 ALTAIR 05 C10 N.C. VDD DRAIN CDC 2.2nF - YCap 2.5V + CURRENT CONTROL - FB/ZCD COMP IREF GND SOURCE R6 C6 6.2K 470nF C7 C5 4.7nF R8 1nF R7 1.2 10k