Freescale streamlines power supply designs with space-saving power IC
(Technology News, 06 May 2008 )
As electronics manufacturers pack more and more features into smaller devices, space is at a premium in the power supply housing, as well as on the system board. To help developers design compact power supplies, Freescale Semiconductor has added the MC34700 power supply integrated circuit (IC) to its portfolio of power management products optimized for space-constrained high-voltage and high-power applications.
Freescale’s MC34700 IC is a 9.0V to 18V quad-output integrated MOSFET device designed to reduce the complexity and streamline the development of power supplies. The MC34700 is available in a 32-lead 5x5mm QFN package, enabling the ability to generate up to four power rails in a small-footprint design. This capability reduces board space requirements over discrete designs. The wide input voltage range makes the device ideal for applications with a nominal 12V supply. The MC34700 features ample operating margin in systems where the 12V supply is only 20 percent accurate.
Four output channels are available in the MC34700 device. Channel 1 is a non-synchronous switching regulator; channels 2 and 3 are synchronous switching regulators; and channel 4 is a low-dropout linear regulator. All switching channels feature voltage-mode control with external compensation, allowing power supplies designed using the MC34700 to be tailored to a wide variety of output regulation and transient performance requirements.
The MC34700 is intended for applications with tight board space requirements and multiple power domains. Target applications include set-top boxes, cable modems, laser printers, fax machines, point-of-sale terminals, small appliances, telecom line cards and DVD players.
The MC34700 device’s four output channels feature programmable output voltages over a wide range. The output of channel 1 can be programmed from 2.0V to 5.25V, and the outputs of channels 2 through 4 can be programmed from 0.7V to 3.6V. This programming flexibility enables generation of power rails for a multitude of downstream components, such as microprocessors, microcontrollers, memory ICs, low-voltage motors and small LCD panels.
The MC34700 features overvoltage, undervoltage, overcurrent and overtemperature protection designed to ensure robust and reliable operation. The device’s fixed switching frequency, internal soft-start and internal power MOSFETs enable rapid power supply design and development by eliminating the need to consider such variables as optimal switching frequency, soft-start time and power MOSFET on-resistance.
