APW7074
Synchronous Buck PWM Controller
Features
•
•
•
•
•
•
•
•
•
•
Single 12V Power Supply Required
0.8V Reference with 1% Accuracy
Shutdown and Soft-start Function
300KHz Fixed Switching Frequency
Voltage Mode PWM Control Design
Up to 100% Duty Cycle
Under-Voltage Protection
Over-Current Protection
SOP-14 Package
Lead Free Available (RoHS Compliant)
General Description
The APW7074 uses fixed 300KHz switching frequency,
voltage mode, synchronous PWM controller which
drives dual N-channel MOSFETs. The device integrates
all of the control, monitoring and protecting functions
into a single package, provides one controlled power
output with under-voltage and over-current protections.
The APW7074 provides excellent regulation for
output load variation. The internal 0.8V temperature-
compensated reference voltage is designed to meet
the requirement of low output voltage applications.
The APW7074 with excellent protection functions:
POR, OCP and UVP. The Power-On-Reset (POR) cir-
cuit can monitor the VCC, EN, and OCSET voltage to
make sure the supply voltage exceeds their
threshold voltage while the controller is running.
The Over-Current Protection (OCP) monitors the out-
put current by using the voltage drop across the upper
and lower MOSFET’ R
DS(ON)
. When the output cur-
s
rent reaches the trip point, the controller will run the
soft-start function until the fault events are removed.
The Under-Voltage Protection (UVP) monitors the volt-
age at FB pin (V
FB
) for short-circuit protection, when
the V
FB
is less 50% V
REF
, the controller will shutdown
the IC directly.
Applications
•
Graphic Cards
Pin Outs
NC
OCSET
SS
COMP
FB
EN
GND
1
2
3
4
5
6
7
SOP-14
TOP V IEW
14
13
12
11
10
9
8
V CC
PV CC
LGA TE
PGND
BOOT
UGA TE
PHASE
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.2 - Feb., 2006
1
www.anpec.com.tw
APW7074
Ordering and Marking Information
APW7074
Lead Free Code
Handling Code
Temp. Range
Package Code
APW7074 K :
APW7074
XXXXX
Package Code
K : SOP - 14
Temp. Range
E : -20 to 70°C
Handling Code
TU : Tube
Lead Free Code
L : Lead Free Device
TR : Tape & Reel
Blank : Original Device
XXXXX- Date Code
Note: ANPEC lead-free products contain molding compounds/die attach materials and 100% matte tin plate
termination finish; which are fully compliant with RoHS and compatible with both SnPb and lead-free soldering
operations. ANPEC lead-free products meet or exceed the lead-free requirements of IPC/JEDEC J STD-020C for
MSL classification at lead-free peak reflow temperature.
Block Diagram
VCC
OCSET
GND
BOOT
EN
Power-On
Reset
I
OCSET
200uA
UGATE
O.C.P
Comparator
V
CC
0.27V
Soft Start
O.C.P
Comparator
50%V
REF
:
2
U.V.P
Comparator
PVCC
PWM
Comparator
Error Amp
V
REF
Oscillator
Sawtooth
Wave
F
OSC
300KHz
PGND
PHASE
I
SS
10uA
SS
Gate Control
LGATE
FB
COMP
Copyright
©
ANPEC Electronics Corp.
Rev. A.2 - Feb., 2006
2
www.anpec.com.tw
APW7074
Absolute Maximum Ratings
Symbol
VCC, PVCC
BOOT
UGATE
LGATE
PHASE
OCSET
FB, COMP
PGND
T
J
T
STG
T
SDR
V
ESD
VCC, PVCC to GND
BOOT to PHASE
UGATE to PHASE <400ns pulse width
>400ns pulse width
LGATE to PGND
PHASE to GND
OCSET to GND
FB, COMP to GND
PGND to GND
Junction Temperature Range
Storage Temperature
Soldering Temperature (10 Seconds)
Minimum ESD Rating
<400ns pulse width
>400ns pulse width
<400ns pulse width
>400ns pulse width
Parameter
Rating
-0.3 to +16
-0.3 to +16
-5 to BOOT+5
-0.3 to BOOT +0.3
-5 to PVCC+5
-0.3 to BOOT +0.3
-5 to +21
-0.3 to 16
VCC+0.3
-0.3 to 7
-0.3 to +0.3
-20 to +150
-65 ~ 150
300
±2
Unit
V
V
V
V
V
V
V
V
°C
°C
°C
KV
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Recommended Operating Conditions
Symbol
VCC, PVCC
V
IN
V
OUT
I
OUT
T
A
T
J
IC Supply Voltage
Converter Input Voltage
Converter Output Voltage
Converter Output Current
Ambient Temperature Range
Junction Temperature Range
Parameter
Rating
10.8 to 13.2
2.2 to 13.2
0.8 to 5
0 to 25
-20 to 70
-20 to 125
Unit
V
V
V
A
°C
°C
Electrical Characteristics
Unless otherwise specified, these specifications apply over VCC=12V, and T
A
=-20~70°C. Typical values are at
T
A
=25
°
C.
Symbol
Parameter
Test Conditions
APW7074
Min
Typ
Max
Unit
INPUT SUPPLY CURRENT
I
CC
VCC Supply Current
(Shutdown mode)
VCC Supply Current
Copyright
©
ANPEC Electronics Corp.
Rev. A.2 - Feb., 2006
UGATE, LGATE and EN = GND
UGATE and LGATE Open
3
0.5
5
1
10
mA
mA
www.anpec.com.tw
APW7074
Electrical Characteristics (Cont.)
Unless otherwise specified, these specifications apply over VCC=12V, and T
A
=-20~70°C. Typical values are at
T
A
=25
°
C.
Symbol
Parameter
Test Conditions
APW7074
Min
9
7.5
Typ
9.5
8
1.3
0.1
1.3
0.1
Max
10.0
8.5
Unit
POWER-ON RESET
Rising VCC Threshold
Falling VCC Threshold
Rising V
OCSET
Threshold
V
OCSET
Hysteresis Voltage
Rising EN threshold Voltage
EN Hysteresis Voltage
OSCILLATOR
F
OSC
V
OSC
Duty
V
REF
Oscillator Frequency
Ramp Amplitude
Duty Cycle Range
Reference Voltage
Reference Voltage Tolerance
PWM ERROR AMPLIFIER
Gain
SR
Open Loop Gain
Slew Rate
FB Input Current
V
COPM
COMP High Voltage
V
COPM
COMP Low Voltage
I
COMP
COMP Source Current
I
COMP
COMP Sink Current
GATE DRIVERS
I
UGATE
Upper Gate Source Current
I
UGATE
Upper Gate Sink Current
I
LGATE
Lower Gate Source Current
I
LGATE
Lower Gate Sink Current
R
UGATE
Upper Gate Sink Impedance
BOOT = 12V, V
UGATE
-V
PHASE
= 2V
BOOT = 12V, V
UGATE
-V
PHASE
= 2V
PVCC = 12V, V
LGATE
= 2V
PVCC = 12V, V
LGATE
= 2V
BOOT = 12V, I
UGATE
= 0.1A
2.6
1.05
4.9
1.4
2
1.6
3
2.4
A
A
A
A
Ω
Ω
V
COMP
= 2V
V
COMP
= 2V
R
L
= 10k, C
L
= 10pF (Note3)
R
L
= 10k, C
L
= 10pF (Note3)
R
L
= 10k, C
L
= 10pF (Note3)
V
FB
= 0.8V
88
15
6
0.1
5.5
0
5
5
1
dB
MHz
V/us
uA
V
V
mA
mA
GBWP Open Loop Bandwidth
-1
(nominal 1.35V to 2.95V)
0
0.80
+1
255
300
1.6
100
345
kHz
V
%
V
%
V
V
V
V
V
V
REFERENCE
R
UGATE
Upper Gate Source Impedance BOOT = 12V, I
UGATE
= 0.1A
Copyright
©
ANPEC Electronics Corp.
Rev. A.2 - Feb., 2006
4
www.anpec.com.tw
APW7074
Electrical Characteristics (Cont.)
Unless otherwise specified, these specifications apply over VCC=12V, and T
A
=-20~70°C. Typical values are
at T
A
=25
°
C.
Symbol
Parameter
Test Conditions
APW7074
Min
Typ
1.3
1.25
20
Max
1.95
1.88
Unit
GATE DRIVERS (Cont.)
R
LGATE
R
LGATE
T
D
UV
FB
I
OCSET
V
OCP
I
SS
Lower Gate Source Impedance
Lower Gate Sink Impedance
Dead Time
FB Under Voltage Level
OCP Voltage (Low-Side)
Soft-Start Charge Current
Percent of V
REF
45
150
230
8
PVCC = 12V, I
LGATE
= 0.1A
PVCC = 12V, I
LGATE
= 0.1A
Ω
Ω
nS
55
250
310
12
%
uA
mV
uA
PROTECTION
50
200
270
10
OCSET Source Current (Hi-Side) V
OCSET
= 11.5V
SOFT START
Note 3:Guaranteed by design.
Typical Application Circuit
1uF
12V
PVCC VCC OCSET
EN
OFF
SS
22nF
1N4148
1nF
1uF
2.37K
1uH
V
IN
ON
470uFx2
470uF
BOOT
0.1uF
UGATE
PHASE
APM2509
2.2uH
V
OUT
1.5nF
APM2506
SCD24
7.5R
1000uFx2
COMP
FB
GND
2.7K
1K
LGATE
PGND
33nF
8.2nF
2K
18R
68nF
Copyright
©
ANPEC Electronics Corp.
Rev. A.2 - Feb., 2006
5
www.anpec.com.tw
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