AP2014/A
Synchronous PWM Controller
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this
product. No rights under any patent accompany the sale of the product.
Rev. 1.2 Nov 29, 2005
1/12
„ Features
- Synchronous Controller in 8-Pin Package
- Operating with single 5V or 12V supply voltage
- Internal 200KHz Oscillator (400KHz for AP2014A)
- Soft-Start Function
- Fixed Frequency Voltage Mode
- 500mA Peak Output Drive Capability
- Protects the output when control FET is shorted
- SOP-8L/PDIP-8L Pb-Free package
„ Applications
- Graphic Card
- Hard Disk Drive
- DDR memory source sink Vtt application
- Low cost on-board DC to DC such as 5V to 3.3V,
2.5V or 1.8V
„ Pin Assignments
SOP-8L/PDIP-8L
1
2
3
45
6
7
8
(Top View)
Vcc
GND
AP2014/A
LDrv
HDrv
Vc
Comp
FB SS
„ General Description
The AP2014 controller IC is designed to provide a
low cost synchronous Buck regulator for on-board
DC to DC converter applications. With the migration
of today’s ASIC products requiring low supply
voltages such as 1.8V and lower, together with
currents in excess of 3A, traditional linear regulators
are simply too lossy to be used when input supply is
5V or even in some cases with 3.3V input supply.
The AP2014 together with dual N-channel
MOSFETs such as AF9410, provide a low cost
solution for such applications. This device features
an internal 200KHz oscillator (400KHz for "A"
version), under-voltage lockout for both Vcc and Vc
supplies, an external programmable soft-start
function as well as output under-voltage detection
that latches off the device when an output short is
detected.
„ Pin Descriptions
Pin
Name
Pin
No.
Description
FB 1
This pin is connected directly to the output of the
switching regulator via resistor divider to provide
feedback to the Error amplifier.
Vcc 2
This pin provides biasing for the internal blocks of
the IC as well as power for the low side driver. A
minimum of 1uF, high frequency capacitor must be
connected from this pin to ground to provide peak
drive current capability.
LDrv 3 Output driver for the synchronous power MOSFET.
GND 4
This pin serves as the ground pin and must be
connected directly to the ground plane. A high
frequency capacitor (0.1 to 1uF) must be connected
from V5 and V12 pins to this pin for noise free
operation.
HDrv 5 Output driver for the high side power MOSFET.
Vc 6
This pin is connected to a voltage that must be at
least 4V higher than the bus voltage of the switcher
(assuming 5V threshold MOSFET) and powers the
high side output driver. A minimum of 1uF, high
frequency capacitor must be connected from this
pin to ground to provide peak drive current
capability.
Comp 7
Compensation pin of the error amplifier. An external
resistor and capacitor network is typically connected
from this pin to ground to provide loop
compensation.
SS 8
This pin provides soft-start for the switching
regulator. An internal current source charges an
external capacitor that is connected from this pin to
ground which ramps up the output of the switching
regulator, preventing it from overshooting as well as
limiting the input current. The converter can be
shutdown by pulling this pin below 0.5V.