AME, Inc.
PWM Control 3A Buck
Converter
AME5107
n Detailed Description
PWM Control
The AME5107 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of
the AME5107, the pulse width varies in a range from 0 to 100%, according to the load current. The ripple voltage
produced by the switching can easily be removed through a filter because the switching frequency remains constant.
Therefore, these converters provide a low-ripple power over broad ranges of input voltage and load current.
Under Voltage Lockout
The under voltage lockout circuit of the AME5107 assures that the high-side MOSFET driver outputs remain in the off
state whenever the supply voltage drops below 3.3V. Normal operation resumes once VCC rises above 3.5V.
RDS(ON) Current Limiting
The current limit threshold is setting by the external resistor connecting from VCC supply to OCSET. The internal
100uA sink current crossing the resistor sets the voltage at the pin of OCSET. When the PWM voltage is less than the
voltage at OCSET, an over-current condition is triggered.
ILOAD x RDS(ON) =IOCSET x ROCSET
See above formula for setting the current limit value.
C
Rev.A.01
7
AME [ ANALOG MICROELECTRONICS ]
