The LTC3704EMS 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 LTC3704EMS 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 LTC3704EMS by connecting the SENSE pin to a resistor in the source of the power MOSFET.
The LTC3704EMS is available in the 10-lead MSOP package.
Feature
- 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: IQ = 10µA
- Programmable Switching Frequency (50kHz to 1MHz) with One External Resistor
- Synchronizable to an External Clock Up to 1.3 × fOSC
- 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 (VDS >36V)
- Small 10-Lead MSOP Package
Applications
- SLIC Power Supplies
- Telecom Power Supplies
- Portable Electronic Equipment
- Cable and DSL Modems
- Router Supplies
(Picture: Pinout)
