NCP1511

Features:

• High Efficiency:
  93% for 1.89 V Output at 3.6 V Input and 150 mA Load Current
  92% for 1.89 V Output at 3.6 V Input and 300 mA Load Current
• Digital Programmable Output Voltages: 1.0, 1.3, 1.5 or 1.89 V
• Output Current up to 500 mA at V_in = 3.6 V
• Low Quiescent Current of 14 A in Pulsed Switching Mode
• Low 0.1 A Shutdown Current
• −30°C to 85°C Operation Temperature
• Ceramic Input/Output Capacitor
• 9 Pin Chip Scale Package
• Pb−Free Package is Available


Application

• Cellular Phones, Smart Phones and PDAs
• Digital Still Cameras
• MP3 Players and Portable Audio Systems
• Wireless and DSL Modems
• Portable Equipment


Pinout




Specifications

Rating	Symbol	Value	Unit
Maximum Voltage All Pins	Vmax	5.5	V
Maximum Operating Voltage All Pins	Vmax	5.2	V
Thermal Resistance, Junction−to−Air (Note 1)	RJA	159	°C/W
Operating Ambient Temperature Range	TA	−30 to 85	°C
ESD Withstand Voltage    Human Body Model (Note 2)                                         Machine Model (Note 2)	VESD	> 2500 > 150	V
Moisture Sensitivity	MSL	Level 1
Storage Temperature Range	Tstg	−55 to 150	°C
Junction Operating Temperature	TJ	−30 to 125	°C

Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied, damage may occur and reliability may be affected.

1. For the 9−Pin Micro Bump package, the R_JA is highly dependent of the PCB heatsink area. R_JA = 159°C/W with 50 mm2 PCB heatsink area.
2. This device series contains ESD protection and exceeds the following tests:
            Human Body Model, 100 pF discharge through a 1.5 k following specification JESD22/A114.
            Machine Model, 200 pF discharged through all pins following specification JESD22/A115.
            Latchup as per JESD78 Class II: > 100 mA.


Description

The NCP1511 step−down PWM DC−DC converter is optimized for portable applications powered from 1−cell Li−ion or 3−cell Alkaline/NiCd/NiMH batteries. This DC−DC converter utilizes a current−mode control architecture for easy compensation and better line regulation. It also uses synchronous rectification to increase efficiency and reduce external part count. The NCP1511 optimizes efficiency in light load conditions when switched from a normal PWM mode to a "pulsed switching" mode. The device also has a built−in oscillator for the PWM circuitry, or it can be synchronized to an external 500 kHz to 1000 kHz clock signal. Finally, it includes an integrated soft−start, cycle−by−cycle current limiting, and thermal shutdown protection. The NCP1511 is available in a chip scale package.