APW7058
Synchronous Buck PWM and Linear Controllers
Features
•
Provides Two Regulated Voltages
- One Synchronous-Rectified Buck PWM
Controller
- One Linear Controller
General Description
The APW7058 integrates one synchronous-rectified
Buck PWM controller and one linear controller to pro-
vide two regulated voltages for graphics cards and
other embedded processor applications. The PWM
controller which drives dual N-channel MOSFETs uses
fixed 600kHz frequency, voltage-mode PWM control
and integrates power-on-reset(POR), built-in soft-start,
output under-voltage monitoring and shutdown func-
tions into a single chip. The linear controller which
drives a N-channel MOSFET bypass transistor allows
users to optimize the transient response by external
components. The POR circuit with hysteresis moni-
tors both 5VCC and 12VCC supply voltages to start
up/shutdown the IC at power-on/off. An internal 0.8V
temperature-compensated reference is designed to
meet the low output voltage requirement for further
applications. The built-in soft-start function sets the
soft-start interval to prevent the output voltages from
overshoot as well as limiting the input currents. The
under-voltage protections monitor the voltages at FB
and FB2 for short-circuit protection. The under-volt-
age protections cycle the soft-start function until 3
times of UVP events are happened. Pulling and hold-
ing the FB2 pin above 1.28V to disable the both
controllers.
•
Low Reference Voltage for Further Applications
- Both Controllers : 0.8V ± 2% Over
Temperature
•
Both Controllers Drive N-Channel MOSFETs
- PWM Controller Drives Dual N-Channel
MOSFETs
- Linear Controller Drives N-Channel MOSFET
•
Built-in PWM Feedback Compensation
- No Steady-State Error
-
Voltage-Mode PWM Control
- Full 0~100% Duty Ratio
- Fast Transient Response
•
Adjustable Outputs by External Resistor Dividers
•
Under-Voltage Monitoring on Both Controllers
•
Small Converter Size
- 600kHz Constant Switching Frequency
- Built-In Soft-Start
- Simple SO-8 Package
•
•
Shutdown Control
Lead Free Available (RoHS Compliant)
Pin Description
Applications
•
•
•
Motherboard
12VCC
UGATE
GND
1
2
3
4
8
7
6
5
FB
FB2
DRIVE2
5VCC
Graphics Cards
LGATE
12V, 5V and 3.3V Inputs DC-DC Converter
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.3 - Mar., 2005
1
www.anpec.com.tw
ANPEC [ ANPEC ELECTRONICS COROPRATION ]
