Low IQ buck controller suits battery-powered or automotive applications
For systems that require multiple low voltage outputs generated from an input voltage as high as 60V, Analog Devices introduces the LTC3372. The Power by Linear power management device features a 60V synchronous buck switching regulator controller followed by four configurable synchronous monolithic buck regulators.
This combination provides up to five high efficiency low quiescent current outputs in a single IC, says Analog Devices, making it particularly suitable for automotive, industrial and medical applications.
The LTC3372’s buck controller operates over a 4.5 to 60V input voltage range and drives an all n-channel MOSFET power stage. Its output can be programmed to either 3.3 or 5.0V and can generate an output current up to 20A. The controller output is typically used to feed the four monolithic buck regulators. Each monolithic buck channel can be programmed to regulate an output voltage as low as 0.8V with a configurable output current up to 4.0A. Eight 1.0A integrated power stages are programmed by the C1-C3 pins into one of eight configurations, from a quad 2.0A buck to a dual 4.0A buck. This allows only one inductor per channel.
The LTC3372 offers a low IQ solution for battery-powered or automotive applications in which one or more power supply rails are always on. With just the high voltage controller enabled, the device draws 15 microA from a 12V input supply while regulating the output to 5.0V at no load. Each monolithic buck regulator adds only 8 microA of additional IQ per channel enabled. The monolithic buck switching frequency can be programmed from 1MHz to 3MHz and can be synchronised to an external clock while the buck controller switches at 1/6 of this frequency. Additional features include foldback current limiting, soft-start, short-circuit protection and output over-voltage protection.
The LTC3372 is available from stock in a thermally enhanced 48-pin 7.0 x 7.0mm QFN package. E and I grades are specified over an operating junction temperature range of -40 to +125 degrees C, and the H grade features operation from -40 to +150 degrees C.