Copyright  ANPEC Electronics Corp.
Rev. A.1 - Jun., 2006
APW7067N
www.anpec.com.tw1
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.
Synchronous Buck PWM and Linear Controller
Features
• Provided Two Regulated Voltages
- Synchronous Buck Converter
- Linear Regulator
• Single 12V Power Supply Required
• Excellent Both Output Voltage Regulation
- 0.8V Internal Reference
- ±1% Over Line Voltage and Temperature
• Integrated Soft-Start for PWM and Linear Outputs
• Programmable Frequency Range
from 150 kHz to 1000kHz
• Voltage Mode PWM Control Design and
Up to 89% (Typ.) Duty Cycle
• Under-Voltage Protection for PWM and Linear
Output
• Over-Current Protection for PWM Output
- Sense Low-Side MOSFET’s RDS(ON)
• SOP-14, QSOP-16 and QFN-16 packages
• Lead Free Available (RoHS Compliant)
Applications
General Description
The APW7067N integrates synchronous buck PWM
and linear controller, as well as monitoring and pro-
tection functions into a single package. The synchro-
nous PWM controller drives dual N-channel MOSFETs,
which provides one controlled power output with under-
voltage and over-current protections. Linear controller
drives an external N-channel MOSFET with under-volt-
age protection.
The APW7067N provides excellent regulation for output
load variation. An internal 0.8V temperature-compensated
reference voltage is designed to meet the requirement
of low output voltage applications. The switching
frequency is adjustable from 150kHz to 1000kHz.
The APW7067N with excellent protection functions:
POR, OCP and UVP. The Power-On Reset (POR)
circuit can monitor VCC12 supply voltage exceeds
its threshold voltage while the controller is running,
and a built-in digital soft-start provides both outputs
with controlled rising voltage. The Over-Current Protection
(OCP) monitors the output current by using the voltage
drop across the lower MOSFET’s RDS(ON), comparing
with internal VOCP (0.25V), eliminating the need for a
current sensing resister. When the output current
reaches the trip point, the controller will shutdown the
IC directly, and latch the converter’s output. The
Under-Voltage Protection (UVP) monitors the voltages
of FB and FBL pins for short-circuit protection. When
the VFB or VFBL is less than 50% of VREF, the controller
will shutdown the IC directly.
• Graphic Cards