AC/DC Power Conversion Low-Power Low-Cost Offline Power Conversion Solutions Examples Linear Regulator LR8 is a high-voltage, low-output current, adjustable linear regulator. It has a wide operating input voltage range of 13.2–450 V. The output current limit is typically 20 mA. * VIN VOUT LR8 ADJ R1 C1 RLOAD C2 R2 *Required for conditions where VIN is less than VOUT. Summary Many applications require their low-power controller circuits to operate from an offline power source. An AC/ DC converter is also required to provide safety isolation from the application to the AC line and to meet EMI emission requirements. Microchip provides a broad-range of cost-effective solutions for AC/DC power conversion to help bring a design to market in the shortest time possible. Non-Isolated AC/DC Application An alternative use for the HV9922, originally designed as an LED driver, is an offline, non-isolated, bias power supply for line-side circuitry. An example of an application would be to provide 50 mA bias for a motor drive controller. It will operate from 85 VAC to 256 VAC, is stable with open and short-circuit loads and since there is no feedback loop, it is unconditionally stable. 1 D Applications ■ ■ ■ ■ ■ Smart appliances Smart meters Telecom/network equipment Offline MCU or DSC power supply Offline SMPS start-up circuits Available Reference Material D 6 D7 4 D5 2 U1 HV9922 GND VDD C1 0.1 µF 50V C5 3.3 µF 400V Varistor DR C3 0.1 µF 400V C4 0.033 µF 400V RV1 AC1 L2 2.2 mH 1 L1 2 22 mH D1 MUR160 R1 VOUT+ 200 Ω D2 C2 0.22 µF 50V D2 VOUT− AC2 This alternative circuit can be modified to provide high-side referenced bias, useful for applications like biasing active current sensing, as shown below. Datasheets ■ HV9922 Datasheet ■ HV9910B Datasheet ■ LR8 Datasheet AC Fuse + Surge Protection VOUT = VZ − Application Notes ■ DN-H02 ■ DN-H03 ■ AN-D17 CO VZ R1 D1 MUR160 L1 22 mH 60 mA C1 3.3 µF VDD C 0.1 µF 1 DR HV9922 GND Adjust C1 value to prevent drop-out. Adjust R1 for minimum duty cycle of 5%. Adjust L1 for ripple control. VZ = < 20 V. Example of Products Device Packages VIN (V) LR8N8-G Linear 12–450 1.2–440 10 −40 to 125 3-pin TO-252, 3-pin TO-92, 3-pin SOT-89 LR12 Linear 12–100 1.2–88 50 −40 to 125 3-pin TO-252, 3-pin TO-92, 8-pin SOIC Inductorless 80–285 (VAC) 9–50 100 −40 to 125 8-pin SOIC HV9921/2/3N8-G Buck 20–400 Adj. 20/50/30 −40 to 125 TO-92, SOT-89 HV9910B Buck 8–450 Adj. External FET −40 to 125 8-pin SOIC, 16-pin SOIC HV9120/3NG-G PWM 10–450 Adj. External FET −55 to 125 16-pin SOIC, 16-pin PDIP, 20-pin PLCC Depletion Mode MOSFETs BVDSX Min. (V) RDSON Max. Min. (mA) VDSOFF Max. (V) ü 450 60 120 −3.5 SR086/7 Device DN3145N8-G Output Voltage (V) IOUT Max. (mA) Operation Temperature (°C) Topology Packages SOT-89 Note: Please refer to Microchip's Analog and Interface Product Selector Guide (DS20001060) for more options and details. Development Board HV9922DB2 Demo Board (HV9922DB2) www.microchip.com/analog Visit our web site for additional product information and to locate your local sales office. Microchip Technology Inc. • 2355 W. Chandler Blvd. • Chandler, AZ 85224-6199 Information subject to change. The Microchip name and logo and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. All other trademarks mentioned herein are property of their respective companies. © 2014, Microchip Technology Incorporated. Energizer and other marks are trademarks owned by Energizer. All Rights Reserved. Printed in the U.S.A. 12/14 DS20005364A