1FEATURES

2• Ideal Load and Line Transient Responses

• 5V to 30V Input Range

• On-Chip Gate Drive

• Convenient CLK_EN# Signal

• Input Under-Voltage Lockout

• High Light-Load Efficiency

• Adjustable Analog Soft Start

• Peak Current Limit

• Over-Voltage Protection

• Error Correction for Good Static Accuracy

• ±1% DAC Accuracy Over Temperature

• Interfaces with the LM2647 System Supply

• Available in TSSOP or WQFN Packages

APPLICATIONS

• Core Voltage Supply for Low Power

Processors

• Low Voltage High Current Buck Regulators

Benefits

• Single Chip Core Power Solution

• Minimum Output Capacitance Required

• Low Cost, Compact Design

DESCRIPTION

The LM27213 is a single-phase synchronous buck

regulator controller designed to fully support a

portable microprocessor. On-chip gate drive makes

for a compact, single chip solution. Output currents in

excess of 25 Amps are possible.

The IC employs a current mode hysteretic control

mechanism. Inductor current is sensed through a low

value sense resistor.

The LM27213 will operate over an input voltage

range of 5V to 30V. The output voltage is

programmed through 6 Voltage Identification (VID)

pins and ranges from 0.700V to 1.708V in 64 steps.

Since the error in the output voltage directly sets the

inductor current, the dynamic response to a large,

fast load transient is close to a square wave. This is

optimal for mode transition requirements. Also, due to

the intrinsic input voltage feedforward characteristic of hysteretic control, the line transient response is

excellent as well.

The IC provides cycle-by-cycle peak current limit,

over-voltage protection, and a power good signal.

The LM27213 fully supports the Stop CPU and Sleep

modes offered by some processors. When enabled,

the IC enters a power-saving “diode emulator” mode

which helps prolong battery runtime for portable

systems.

The LM27213 also has a soft start feature for the

external adjustment of soft start speed.