Datasheet

LM5070

SNVS308G –OCTOBER 2004–REVISED APRIL 2013

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Gate Driver and Maximum Duty Cycle Limit

The LM5070 provides an internal gate driver (OUT), which can source and sink a peak current of 800mA. The

LM5070 is available in two duty cycle limit options. The maximum output duty cycle is typically 80% for the

LM5070-80 option and precisely equal to 50% for the LM5070-50 option. The maximum duty cycle function for

the LM5070-50 is accomplished with an internal toggle flip-flop which ensures an accurate duty cycle limit. The

internal oscillator frequency of the LM5070-50 is therefore twice the operating frequency of the PWM controller

(OUT pin).

The 80% maximum duty cycle limit of the LM5070-80 is determined by the internal oscillator and varies more

than the 50% limit of the LM5070-50. For the LM5070-80, the internal oscillator frequency and the operational

frequency of the PWM controller are equal.

Thermal Protection

Internal thermal shutdown circuitry is provided to protect the integrated circuit in the event the maximum junction

temperature is exceeded. This feature prevents catastrophic failures from accidental device overheating. When

activated, typically at 165 degrees Celsius, the controller is forced into a low power standby state, disabling the

output driver, bias regulator, main interface pass MOSFET, and classification regulator if enabled. After the

temperature is reduced (typical hysteresis = 25°C) the V

regulator will be enabled and a softstart sequence

initiated.

Product Folder Links: LM5070