APW7199 Datasheet, PDF (1/24 Pages) Anpec Electronics Coropration – High-Performance Step-Down PWM Controller with PFM

APW7199
High-Performance Step-Down PWM Controller with PFM
Features
General Description
• Operates from An Input Battery Voltage Range of
+3V to +25V
• ±0.6% 0.5V Reference
- Over Line, Load Regulation, and Operating Temp.
• Drive Dual Low Cost N-Channel MOSFETs
- Adaptive Shoot-Through Protection
• Power-On-Reset Monitoring on VCC Pin
• PFM Mode for Increasing Light Load Efficiency
• Constant-On-Time Control Scheme
- Switching Frequency Compensation for PWM
Operation
• 300kHz Constant Switching Frequency
• Integrated MOSFET Drivers and Bootstrap Diode
• Internal Soft-Start and Soft-Stop
• Power Good Monitoring
• 70% Under-Voltage Protection
• 125% Over-Voltage Protection
- Using Low-Side MOSFET’s R_DS(ON)
• Over-Temperature Protection
• TDFN-10 3mmx3mm Package
• Lead Free and Green Devices Available
(RoHS Compliant)
Applications
• Notebook
• Low Cost PC
• Wide Input DC/DC Regulators
The APW7199 is a single-phase, constant-on-time, and
synchronous PWM controller, which drives N-channel
MOSFETs. An internal 0.5V temperature-compensated
reference voltage with high accuracy is designed to meet
the requirement of low output voltage applications. The
APW7199 steps down high voltage to generate low-volt-
age chipset or RAM supplies in notebook computers.
The PWM controller operates fixed 300kHz pseudo-con-
stant frequency PWM with an adaptive constant-on-time
control. The device provides excellent transient response
and accurate DC voltage output in either PFM or PWM
Mode. In Pulse Frequency Mode (PFM), the APW7199 pro-
vides very high efficiency over light to heavy loads with
loading-modulated switching frequencies. The device
works in ultrasonic mode with PFM at no load. The unique
ultrasonic mode maintains the switching frequency above
20kHz, which eliminates noise in audio applications.
The APW7199 is equipped with accurate over-current,
output under-voltage, and output over-voltage protections.
A Power-On-Reset function monitors the voltage on VCC
to prevent wrong operation during power-on. The
APW7199 has a 1.5ms digital soft-start to ramp up the
output voltage to reduce the start-up current. A soft-stop
function actively discharges the output capacitors with
controlled reverse inductor current.
The APW7199 is available in TDFN3x3-10 package.
Simplified Application Circuit
5V
V_IN
BOOT
EN/EXTREF
VCC
UGATE
PHASE
Q1
L_OUT
V_OUT
POK
LGATE/OCSET
Q2 C_OUT
R_OCSET
APW7199
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.4 - Oct., 2010
www.anpec.com.tw