1FEATURES

2• Input Power from 2.2V to 16V

• Output Voltage Adjustable Down to 0.6V

• Power Good flag, Adjustable Soft-Start and

Output Enable for Easy Power Sequencing

• Output Over-Voltage and Under-Voltage Latch-

Off (LM2727)

• Output Over-Voltage and Under-Voltage Flag

(LM2737)

• Reference Accuracy: 1.5% (0°C - 125°C)

• Current Limit Without Sense Resistor

• Soft Start

• Switching Frequency from 50 kHz to 2 MHz

• TSSOP-14 Package

APPLICATIONS

• Cable Modems

• Set-Top Boxes/ Home Gateways

• DDR Core Power

• High-Efficiency Distributed Power

• Local Regulation of Core Power

DESCRIPTION

The LM2727 and LM2737 are high-speed,

synchronous, switching regulator controllers. They

are intended to control currents of 0.7A to 20A with

up to 95% conversion efficiencies. The LM2727

employs output over-voltage and under-voltage latch-

off. For applications where latch-off is not desired, the

LM2737 can be used. Power up and down

sequencing is achieved with the power-good flag,

adjustable soft-start and output enable features. The

LM2737 and LM2737 operate from a low-current 5V

bias and can convert from a 2.2V to 16V power rail.

Both parts utilize a fixed-frequency, voltage-mode,

PWM control architecture and the switching

frequency is adjustable from 50kHz to 2MHz by

adjusting the value of an external resistor. Current

limit is achieved by monitoring the voltage drop

across the on-resistance of the low-side MOSFET,

which enhances low duty-cycle operation. The wide range of operating frequencies gives the power

supply designer the flexibility to fine-tune component

size, cost, noise and efficiency. The adaptive, nonoverlapping

MOSFET gate-drivers and high-side

bootstrap structure helps to further maximize

efficiency. The high-side power FET drain voltage can

be from 2.2V to 16V and the output voltage is

adjustable down to 0.6V.