APW8812 Datasheet, PDF (1/24 Pages) Anpec Electronics Coropration – System Power PWM Controller for Notebook Computers with Charge Pump

APW8812
System Power PWM Controller for Notebook Computers with Charge Pump
Features
Simplified Application Circuit
• Wide Input voltage Range from 6V to 25V
• Provide 5 Independent Outputs with ±1.5% Accu-
racy Over-Temperature
- PWM1 Controller with Adjustable (2V to 5.5V) Out-
put
- PWM2 Controller with Adjustable (2V to 5.5V) Out-
put
- 100mA Low Dropout Regulator (LDO5) with Fixed
5V Output
- 100mA Low Dropout Regulator (LDO3) with Fixed
3.3V Output
- 270kHz Clock Signal for 15V Charge Pump (Used
VOUT1 as Its Power Supply)
General Description
• Excellent Line/Load Regulations about ±1.5% Over- _{The APW8812 integrates dual step-down, constant-on-}
Temperature Range
time, synchronous PWM controllers (that drives dual N-
• ±1%, (±1.5%, 50µA) 2.0V Reference Voltage Output _{channel MOSFETs for each channel) and two low drop-}
• Built-In POR Control Scheme Implemented
out regulators as well as various protections into a chip.
• Selectable Forced-PWM or Automatic PFM/PWM _{The PWM controllers step down high voltage of a battery}
(with Selectable Ultrasonic Operation)
to generate low-voltage for NB applications. The output
• Constant-On-Time Control Scheme with Frequency _{of PWM1 and PWM2 can be adjusted from 2V to 5.5V by}
Compensation for PWM Mode
setting a resistive voltage-divider from VOUTx to GND.
• Selectable Switching Frequency in PWM Mode
The linear regulators provide 5V and 3.3V output for
• Built-in Digital Soft-Start for PWM Outputs and Soft- _{standby power supply. The linear regulators provide up}
Stop for PWM Outputs and LDO Outputs
to 100mA output current. When the PWMx output voltage
• Integrated Bootstrap Forward P-CH MOSFET
is higher than LDOx bypass threshold, the related LDOx
• High Efficiency over Light to Full Load Range _{regulator is shut off and its output is connected to VOUTx}
(PWMs)
by internal switchover MOSFET. It can save power
• Built-in Power Good Indicators (PWMs)
dissipation. The charge pump circuit with 270kHz clock
• Independent Enable Inputs (PWMs, LDO)
driver uses VOUT1 as its power supply to generate ap-
• 70% Under-Voltage and 125% Over-Voltage Protec- _{proximately 15V DC voltage.}
tions (PWM)
• Adjustable Current-Limit Protection (PWMs)
The APW8812 provides excellent transient response and
accurate DC output voltage in either PFM or PWM Mode.
- Using Sense Low-Side MOSFET’s R_DS(ON)
• Over-Temperature Protection
In Pulse-Frequency Mode (PFM), the APW8812 provides
very high efficiency over light to heavy loads with loading-
• 4mmx4mm Thin QFN-24 (TQFN4x4-24A) package _{modulated switching frequencies. The Forced-PWM}
• Lead Free and Green Device Available (RoHS _{Mode works nearly at constant frequency for low-noise}
Compliant)
requirements. The unique ultrasonic mode maintains the
switching frequency above 25KHz, which eliminates
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.
1
Rev. A.2 - Sep., 2012
www.anpec.com.tw