Buck regulator suits li-ion battery-powered apps

The LTC3604 4MHz synchronous buck regulator is suitable for applications powered from dual-cell li-ion battery stacks, as well as 5 and 12V intermediate bus systems.

It operates from an input voltage of 3.6 to 15V and incorporates a constant frequency/controlled on-time, current-mode architecture.

It can deliver up to 2.5A of continuous output current at output voltages as low as 0.6V from a 3 x 3mm QFN or MSOP-16E package.

Its current mode operation is said to offer excellent line and load transient response, even with high step-down ratios.

Its switching frequency is user programmable from 800kHz to 4MHz, enabling the use of small, low-cost capacitors and inductors.

The LTC3604 uses internal switches with RDS(ON) of 100 and 130mOhms to deliver efficiencies as high as 95 per cent.

Its control architecture enables it to achieve duty cycles as low as five per cent, while maintaining switching frequencies as high as 2.25MHz, making it suitable for high step-down-ratio applications, such as 12V in to 1.2V out conversions.

Burst Mode operation is used to maximise light-load efficiency, requiring 300uA (at no load), and making the LTC3604 well suited for applications demanding maximum battery run time.

For applications requiring the lowest possible noise, the LTC3604 can be configured to run in forced continuous mode, for minimum noise and potential RF interference.

Additional features include a power-good voltage monitor, output-voltage tracking capability and short-circuit protection.

The LTC3604EUD is available in a 3 x 3mm QFN-16 and the leaded version, the LTC3604EMSE, is available in a MSOP-16E package.

Industrial-grade versions, the LTC3604IUD and LTC3604IMSE, are guaranteed to operate over the -40 to 125C operating junction temperature range.

Back to top