APW8821
Notebook PWM Controller with Differential Voltage Feedback
Features
General Description
• Adjustable Output Voltage from +0.5V to +3.3V
The APW8821 is a single-phase, constant on-time, syn-
- 0.5V Reference Voltage
chronous PWM controller, which drives N-channel
- +0.6% Accuracy
MOSFETs. The APW8821 steps down high voltage to
generate low-voltage chipset or RAM supplies in note-
• Operates from An Input Battery Voltage Range of book computers.
+1.8V to +28V
The APW8821 provides excellent transient response and
• Remote Feedback Sense for Excellent Output
Voltage
accurate DC voltage output in either PFM or PWM Mode.
In Pulse Frequency Mode (PFM), the APW8821 provides
very high efficiency over light to heavy loads with loading-
• REFIN Function for Over-clocking Purpose from
0.5V~2.5V range
• Power-On-Reset Monitoring on VCC Pin
modulated switching frequencies. In PWM Mode, the con-
verter works nearly at constant frequency for low-noise
requirements. APW8821 is built in remote sense func-
tion for applications that require remote sense.
• Excellent line and load transient responses
The APW8821 is equipped with accurate positive cur-
• PFM mode for increased light load efficiency
• 350kHz Constant PWM Switching Frequency
• Integrated MOSFET Drivers
• Integrated Bootstrap Forward P-CH MOSFET
rent limit, output under-voltage, and output over-volt-
age protections, perfect for NB applications. The Power-
On-Reset function monitors the voltage on VCC to
prevent wrong operation during power-on. The
APW8821 has a 1ms digital soft start and built-in an
• Adjustable Integrated Soft-Start and Soft-Stop
integrated output discharge device for soft stop. An
• Power Good Monitoring
• 70% Under-Voltage Protection
• 125% Over-Voltage Protection
• Adjustable Current-limit protection
internal integrated soft-start ramps up the output volt-
age with programmable slew rate to reduce the start-
up current. A soft-stop function actively discharges the
output capacitors.
The APW8821 is available in 10pin TDFN 3x3 package
-Using Sense Low-Side MOSFET?¦s RDS(ON)
respectively.
• Over-Temperature Protection
• TDFN-10 3x3 package
• Lead Free and Green Device Available
(RoHS Compliant)
Applications
• Notebook
• Table PC
• Hand-Held Portable
• AIO PC
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and
advise customers to obtain the latest version of relevant information to verify before placing orders.
Copyright © ANPEC Electronics Corp.
Rev. A.1 - Feb., 2012
1
www.anpec.com.tw
Free Datasheet http://www.datasheet4u.com/
