特点
High Efficiency Operation (No Sense Resistor Required)
Wide Input Voltage Range: 2.5V to 36V
Current Mode Control Provides Excellent Transient Response
High Maximum Duty Cycle (Typ 92%)
±1% Internal Voltage Reference
±2% RUN Pin Threshold with 100mV Hysteresis
Micropower Shutdown: I
Q
= 10μA
Programmable Operating Frequency (50kHz to 1MHz) with One External Resistor
Synchronizable to an External Clock Up to 1.3 x f
OSC
User-Controlled Pulse Skip or Burst Mode? Operation
Internal 5.2V Low Dropout Voltage Regulator
Capable of Operating with a Sense Resistor for High Output Voltage Applications (V
DS
>36V)
Small 10-Lead MSOP Package
典型应用
典型应用
描述
The LTC?3704 is a wide input range, current mode, positive-to-negative DC/DC controller that drives an N-channel power MOSFET and requires very few external components. Intended for low to high power applications, it eliminates the need for a current sense resistor by utilizing the power MOSFET’s on-resistance, thereby maximizing efficiency.
The IC’s 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. Burst Mode operation at light loads, a low minimum operating supply voltage of 2.5V and a low shutdown quiescent current of 10μA make the LTC3704 ideally suited for battery-operated systems.
For applications requiring constant frequency operation, the Burst Mode operation feature can be defeated using the MODE/SYNC pin. Higher than 36V switch voltage applications are possible with the LTC3704 by connecting the SENSE pin to a resistor in the source of the power MOSFET.
The LTC3704 is available in the 10-lead MSOP package.