LM34927MR/NOPB

The LM34927 regulator integrates all the features necessary to implement a low-cost, high-efficiency isolated bias regulator. This high-voltage regulator incorporates two 100V N-channel MOSFET switches — a high-side buck switch and a low-side synchronous switch. The constant on-time (COT) control scheme employed by the LM34927 eliminates loop compensation while delivering excellent transient response. The regulator's on-time is inversely proportional to the input voltage, a characteristic that keeps the switching frequency relatively constant. An integrated sensing circuit performs intelligent peak current limiting. Additional features include a programmable input undervoltage comparator to inhibit operation under low-voltage conditions. Protection features include thermal shutdown and VCC undervoltage lockout (UVLO). The LM34927 is available in WSON-8 and SO PowerPAD-8 plastic packages.

Applications

• Isolated telecom bias supply
• Isolated automotive and industrial electronic components

Key features

• 7.5V to 100V wide input voltage range
• Integrated 600mA high-side and low-side switches
• No Schottky diode required
• Constant on-time control
• No loop compensation required
• Ultra-fast transient response
• Near-constant operating frequency
• Intelligent peak current limiting
• Adjustable output voltage (1.225V reference voltage)
• 2% feedback reference voltage accuracy
• Frequency adjustable up to 1MHz
• Adjustable UVLO
• Remote shutdown
• Thermal shutdown
• Package: 8-pin WSON, 8-pin SO PowerPAD