General Description

The RT5744 and RT5746 are step-down switching

voltage regulators that deliver a digitally programmable

output from an input voltage supply of 2.5V to 5.5V. The

output voltage is programmed through an I2C interface

that can operate up to 3.4MHz.

Using a proprietary architecture with synchronous

rectification, the RT5744 and RT5746 are capable of

delivering continuous 4A and 6A, maintaining that

efficiency at load currents as low as 10mA. The

regulator operates at a nominal fixed frequency of

2.4MHz, which reduces the external component counts.

Additional output capacitance can be added to improve

regulation during load transients without affecting

stability.

At moderate and light loads, Pulse Frequency

Modulation (PFM) is used to operate in power-saving

mode with a typical quiescent current of 45A at room

temperature. Even with such a low quiescent current,

the part exhibits excellent transient response during

large load swings. At higher loads, the system

automatically switches to fixed frequency control,

operating at 2.4MHz. In shutdown mode, the supply

current is typically 0.1A, and is excellent in reducing

power consumption. The PFM mode can be disabled if

the fixed frequency is desired. The RT5744 and RT5746

are available in WL-CSP-14B 1.31x2.02 (BSC) package.

The recommended junction temperature range is −40C

to 125C.

Features

⚫ Programmable Output Voltage Range

 0.27V to 1.4V, 6.25mV/bit

⚫ Programmable Slew Rate for Voltage Transitions

⚫ Steady 2.4MHz Switching Frequency

⚫ Fast Load Transient

⚫ Continuous Output Current Capability: 4A/6A

⚫ 2.5V to 5.5V Input Voltage Range

⚫ Digitally Programmable Output Voltage

⚫ I

2C-Compatible Interface Up to 3.4Mbps

⚫ PFM Mode for High Efficiency at Light Load

⚫ Quiescent Current in PFM Mode: 45A (Typical)

⚫ Input Undervoltage Lockout (UVLO)

⚫ Thermal Shutdown and Overload Protection

⚫ Power Good Indicator

Applications

⚫ Application, Graphic, and DSP Processors

⚫ ARMTM, TegraTM, OMAPTM, NovaThorTM,

ARMADATM, KraitTM, etc.

⚫ Hard Disk Drives, LPDDR3, LPDDR4, LPDDR5

⚫ Tablets, Netbooks, Ultra-Mobile PCs

⚫ Smart Phones

⚫ Gaming Devices