The LTC1871EMS-1#PBF is a wide input range current mode boost flyback or SEPIC Controller that drives an N-channel power MOSFET and requires very few external components. It eliminates the need for a current sense resistor by utilizing the power MOSFETs on-resistance, thereby maximizing efficiency. Higher output voltage applications are possible with the LTC1871-1 by connecting the SENSE pin to a resistor in the source of the power MOSFET. The ICs operating frequency can be set with an external resistor over a 50kHz to 1MHz range and can be synchronized to an external clock using the MODE/SYNC pin. The LTC1871-1 differs from the LTC1871 by having a lower pulse skip threshold, making it ideal for applications requiring constant frequency operation at light loads. The lower pulse skip threshold also helps maintain constant frequency operation in applications with a wide input voltage range.
High efficiency (no sense resistor required)
Current mode control provides excellent transient response
High maximum duty cycle (92% typical)
Ultra low pulse skip threshold for wide input range
Programmable operating frequency with one external resistor
Synchronizable to an external clock up to 1.3 x fOSC
User-controlled pulse skip or Burst Mode? Operation
Internal 5.2V low dropout voltage regulator
Output over-voltage protection
Capable of operating with a sense resistor for high output voltage
