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.
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
Pin Descriptions
Pin
Name
Pin
No.
1
Description
This pin is connected directly to the output of the
switching regulator via resistor divider to provide
feedback to the Error amplifier.
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.
Output driver for the synchronous power MOSFET.
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.
Output driver for the high side power MOSFET.
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.
Compensation pin of the error amplifier. An external
resistor and capacitor network is typically connected
from this pin to ground to provide loop
compensation.
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.
(Top View)
FB
1
8
SS
FB
Vcc 2
7 Comp
AP2014/A
LDrv 3
6 Vc
GND 4
5 HDrv
SOP-8L/PDIP-8L
Vcc
LDrv
GND
HDrv
2
3
4
5
Vc
6
Comp
7
SS
8
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
AP2014/A
Synchronous PWM Controller
Ordering Information
AP2014/A X
Package
S: SOP-8L
N: PDIP-8L
X
Packing
Blank : Tube
A : Taping
Block Diagram
Vc
6
3V
20uA
0.5V
FbLo Comp
-
+
POR
64uA
Max
1.25V
25K
Fb
Comp
1
7
Vcc
+ 0.2V
4.0V
Vc
3.5V
-
+ 0.2V
-
4
GND
25K
Error Amp
+
-
POR
SS
8
Ct
Oscillator
+
-
Error Comp
S
R
Q
5 HDrv
2
3
Vcc
LDrv
Reset Dom
Bias
Generator
3V
1.25V
POR
Absolute Maximum Ratings
Symbol
V
CC
V
C
T
ST
T
J
θ
JC
θ
JA
Parameter
Vcc Supply Voltage
Vc Supply Voltage (not rated for inductive load)
Storage Temperature Range
Operating Junction Temperature Range
Thermal Resistance Junction to Case
Thermal Resistance Junction to Ambient
Range.
20
32
-65 to 150
0 to 125
90
250
o
o
Unit
V
V
o
o
C
C
C/W
C/W
Anachip Corp
www.anachip.com.tw
2/12
Rev. 1.2 Nov 29, 2005
AP2014/A
Synchronous PWM Controller
Electrical Characteristics
Unless otherwise specified, these specifications apply over V
CC
=5V, V
C
=12V and T
A
=0 to 70°C. Typical values refer to T
A
=25°C. Low duty
cycle pulse testing is used which keeps junction and case temperatures equal to the ambient temperature.
