• 800V Integrated Power MOSFET
• Pseudo Fixed Frequency
• Nominal Switching Frequency: 120kHz
• Frequency Fold Back and Burst Mode Control
• FSW Modulation to Reduce EMI Noise
• Supports Flyback and Buck Topologies
• PSR/SSR Optional for Flyback Topology
• HV Start Up from DRAIN
• Peak Current Limit: 590mA
• Wide VCC Operating Range: 4.5V~25.5V
• VCC OVP, OLP, OTP, Input OVP (through ENB pin)
• Internal Soft Start Process  Compact Package: SSOP10

The SQ38343 is a peak current mode flyback/buck converter that integrates a controller with an 800V MOSFET. It features pseudo fixed frequency control which can avoid sub-harmonic oscillation at CCM and duty>50%. Frequency fold back control is used to achieve high efficiency at medium and light load conditions. The device automatically enters burst mode during light or no-load conditions. When used in flyback topology, the device can be configured to use either PSR (Primary Side Regulation) or SSR (Secondary Side Regulation) mode.

The SQ38343 offers a wide VCC operating range from 4.5V to 25.5V, which can support buck converter configuration for output voltages as low as 5V. Quick start-up is enabled by using an integrated HV (High Voltage) start-up circuit.

The SQ38343 provides comprehensive protections including VCC OVP (Overvoltage Protection), OLP (Overload Protection), OTP (Over temperature Protection) and input/output OVP using the ENB pin for reliable operation.

The SQ38343 is available with compact SSOP10 package.