AAT1157

Features:

• VIN Range: 2.7V to 5.5V
• Up to 95% Efficiency
• 110 mΩ RDS(ON) Internal Switches
• <1µA Shutdown Current
• 1MHz Buck Switching Frequency
• Fixed or Adjustable VOUT 0.8V
• Integrated Power Switches
• Current Mode Operation
• Internal Compensation
• Stable with Ceramic Capacitors
• Constant PWM Operation for Low Output Ripple
• Internal Soft Start
• Over-Temperature Protection
• Current Limit Protection
• 16-Pin QFN 3x3mm Package
• -40°C to +85°C Temperature Range


Application

• HDD MP3 Players
• Notebook Computers
• PDAs
• Point-of-Load Regulation
• Set Top Boxes
• Smart Phones
• Wireless Notebook Adapters


Pinout




Specifications

Symbol	Description	Value	Units
VCC, VP	VCC, VP to GND	6	V
VLX	LX to GND	-0.3 to VP + 0.3	V
VFB	FB to GND	-0.3 to VCC + 0.3	V
VEN	EN to GND	-0.3 to -6	V
TJ	Operating Junction Temperature Range	-40 to150	°C
VESD	ESD Rating2 - HBM	3000	V

Description

The AAT1157 SwitchReg™ is a member of AnalogicTech's Total Power Management IC™ (TPMIC™) product family. The step-down switching converter is ideal for applications where fixed frequency and low ripple are required over the full range of load conditions. The 2.7V to 5.5V input voltage range makes the AAT1157 ideal for singlecell lithium-ion/polymer battery applications. Capable of up to 1.2A with internal MOSFETs, the current-mode controlled IC provides high efficiency over a wide operating range. Fully integrated compensation simplifies system design and lowers external parts count. The device operates at a fixed 1MHz switching frequency across all load conditions.

The AAT1157 is available in the Pb-free, 16-pin 3x3mm QFN package and is rated over the -40°C to +85°C temperature range.