STEVAL-ISA105V1 Power supply for energy meter and power line modem based on the ALTAIR04-900 Databrief Features Min. operating voltage V : 90 V acmin ac Max. operating voltage V : 265 V , 440 acmax ac V max Topology: quasi-resonant flyback converter, primary side regulation Mains frequency fL: 50 Hz +/-3 Hz Input/output isolation: yes, Galvanic isolation >2.7 KV Nominal output voltage: 5 V/70 mA nominal, 1 A max. feedback. This eliminates the need for the 3.3 V/30 mA nominal, 150 mA max. optocoupler, the secondary voltage reference, as 12 V/2 mA nominal, 100 mA max. well as the current sensor, while still maintaining 5 V ISO/2 mA nominal, 80 mA max. quite accurate regulation. Total output power P : 1 W nominal, 7.5 W out (during transmission mode) Typical efficiency 230 V : > 75% ac Output voltage pk-pk ripple: < 100 mV Protection: short-circuit protection Reflected voltage of transformer, V : 100 V R RoHS compliant Description The STEVAL-ISA105V1 demonstration board implements a power supply based on a quasi- resonant mode of operation using ST primary side ALTAIR04-900 flyback switch. The ALTAIR04-900 is a high-voltage all-primary sensing switcher intended for operating directly from the rectified mains with minimum external parts. It combines a high-performance low voltage PWM controller chip and a 900 V avalanche- rugged power section in the same package. The controller is a current-mode specifically designed for offline quasi-resonant flyback converters. The device is capable of providing constant output voltage using all primary sensing August 2012 Doc ID 023539 Rev 1 1/4 This is information on a product in full production. www.st.com 42 2 2 2 )2 , 5 2 6 5 2 2 2 -/ Schematic diagram STEVAL-ISA105V1 1 Schematic diagram Figure 1. Schematic diagram 6 IO . I 6 S OS 2 + 2 + N& + N& W U& 6 ,O %3 2 W 6 U& ,O %3 2 N& - 2 N& N& 0 0 4 4 W U& 6 ,O %3 2 , 2, - ). ( ). ( 5 % 6 6 W U& 6 ,O %3 2 W 6 U& ,O %3 2 W U& 6 ,O %3 2 303 ( 4 4303 ( 03 ( 34 42 N& N& 3 44( 3 / % 52 ., ). 3 / % 52 ). 2 ). % ) - - - - 2 2 2 2 ),% . N& 4 / -0 & 6 U N& & 6 ( , M N N& + 2 + N& + + 3 - 2 6 ,/04)/. 3/ , . 0 Y 2/4 Doc ID 023539 Rev 1 /5 % 7 ).92 + 7 + 6 6 N& 6 U& , M( 6 U& /5 ).9 - AP 9 % 6 2 2 2 2