Dual 3 MHz, 800 mA Buck Regulators with Two 300 mA LDOs

The ADP5037 combines two high performance buck regulators and two low dropout (LDO) regulators in a small, 24-lead 4 mm × 4 mm LFCSP to meet demanding performance and board space requirements.

The high switching frequency of the buck regulators enables tiny multilayer external components and minimizes the board space. When the MODE pin is set high, the buck regulators operate in forced PWM mode. When the MODE pin is set low and the load is above a predefined threshold, the buck regulators operate in PWM mode. When the load current falls below a predefined threshold, the regulator operates in power save mode (PSM), improving the light-load efficiency.

The two bucks operate out of phase to reduce the input capacitor requirement. The low quiescent current, low dropout voltage, and wide input voltage range of the ADP5037 LDOs extend the battery life of portable devices. The ADP5037 LDOs maintain power supply rejection greater than 60 dB for frequencies as high as 10 kHz while operating with a low headroom voltage.

Regulators in the ADP5037 are activated though dedicated enable pins. The default output voltages can be externally set in the adjustable version or factory programmable to a wide range of preset values in the fixed voltage version.

APPLICATIONS

* Power for processors, ASICS, FPGAs, and RF chipsets

* Portable instrumentation and medical devices

* Space constrained devices

* Main input voltage range: 2.3 V to 5.5 V

* Two 800 mA buck regulators and two 300 mA LDOs

* 24-lead, 4 mm × 4 mm LFCSP package

* Regulator accuracy: ±1.8%

* Factory programmable or external adjustable VOUTx

* 3 MHz buck operation with forced PWM and auto PWM/PSM modes