Date: 04/11/2010

2MHz, synchronous buck DC/DC Controller from Linear

Linear Technology Corporation has unveiled the LTC3833, a high frequency controlled on-time synchronous sbuck DC/DC controller with differential output voltage sensing and clock synchronization. Linear says the controlled on-time, valley current-mode architecture forces a very fast transient response by increasing its operating frequency during a transient event, allowing the LTC3833 to recover from a large load step in only a few cycles. Operating from a 4.5V to 38V input voltage this Power IC is suitable for applications including most intermediate bus voltages. Strong onboard N-channel MOSFET gate drivers can drive high power external MOSFETs for high load current, up to 25A in applications with output voltages ranging from 0.6V to 5.5V, making it ideal for point-of-load requirements.
The other advantages listed by Linear include:
The LTC3833’s differential amplifier provides true remote output voltage sensing of both the positive and negative terminals, enabling high accuracy regulation independent of IR losses (up to ±500mV) in trace runs, vias and interconnects. A low 20ns minimum on time allows for a high step-down ratio power supply at high frequency operation. The operating frequency is selectable from 200kHz to 2MHz or can be synchronized to an external clock. The output current is monitored by sensing the voltage drop across the output inductor (DCR) for highest efficiency or by using a sense resistor. Additional features include an onboard bias voltage LDO, soft-start or tracking, adjustable current limit, overvoltage protection, current limit foldback and external VCC control.

Package: Thermally enhanced 3mm x 4mm QFN-20 or TSSOP-20E.

Operating temperature range: -40°C to 125°C

Price: Each US$2.65 for 1K pieces