Copyright
ANPEC Electronics Corp.
Rev. A.2 - Jun., 2006
APW7068
www.anpec.com.tw
1
Features
Applications
General Description
The APW7068 integrates synchronous buck
PWM, linear controller, and 0.8V Reference Out Voltage,
as well as the monitoring and protection functions
into a single package. The fixed 300KHz switching
frequency synchronous PWM controller drives
dual N-channel MOSFETs, which provides one controlled
power output with over-voltage and over-current
protections. Linear controller drives an external
N-channel MOSFET with under-voltage protection.
The APW7068 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 APW7068 with excellent protection functions:
POR, OCP, OVP 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 R
DS(ON)
,
comparing with the voltage of OCSET pin. When the out-
put 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 voltage of FBL pin for short-circuit protection. When
the V
FBL
is less than 50% of V
REF
, the controller will
shutdown the IC directly. The Over-Voltage Protection
(OVP) monitors the voltage of FB. When the V
FB
is
over 135% of V
REF
, the controller will make Low-
side gate signal fully turn on until the fault events are
removed.
Graphic Cards
Synchronous Buck PWM and Linear Controller with 0.8V Reference Out Voltage
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.
Two Regulated Voltages and REF_OUT
- Synchronous Buck Converter
- Linear Regulator
- REF_OUT = 0.8V1% with 3mA source current
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
300KHz Fixed Switching Frequency
Voltage Mode PWM Control Design and Up to
89%(Typ.) Duty Cycle
Under-Voltage Protection Monitoring Linear
Output
Over-Voltage Protection Monitoring PWM Output
Over-Current Protection for PWM Output
- Sense Low-side MOSFET's R
DS(ON)
SOP-14, QSOP-16 and QFN-16 packages
Lead Free Available (RoHS Compliant)
Copyright
ANPEC Electronics Corp.
Rev. A.2 - Jun., 2006
APW7068
www.anpec.com.tw
2
Pinouts
1
3
2
4
6
5
7
8
B
O
O
T
F
S
_
D
I
S
DRIVE
FB
COMP
A
G
N
D
FBL
D
G
N
D
U
G
A
T
E
P
H
A
S
E
OCSET
LGATE
PGND
V
C
C
1
2
REF_OUT
V
C
C
1
2
QFN-16
TOP VIEW
12
10
11
9
15
16
14
13
Metal GND
Pad
(Bottom)
1
3
2
4
6
5
7
8
BOOT
FS_DIS
DRIVE
FB
COMP
GND
FBL
GND
16
14
15
13
11
12
9
UGATE
PHASE
OCSET
LGATE
PGND
VCC12
REF_OUT
VCC12
QSOP-16
TOP VIEW
10
DRIVE
1
3
2
4
6
5
7
BOOT
FS_DIS
FB
COMP
GND
FBL
14
12
13
11
9
10
8
UGATE
PHASE
OCSET
LGATE
PGND
VCC12
REF_OUT
SOP-14
TOP VIEW
Ordering and Marking Information
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.
APW7068
Handling Code
Temp. Range
Package Code
APW7068 K :
APW7068
XXXXX
XXXXX - Date Code
Lead Free Code
APW7068 Q :
APW7068
XXXXX
XXXXX - Date Code
APW7068 M :
APW7068
XXXXX
XXXXX - Date Code
Package Code
K : SOP - 14 M : QSOP - 16 QA : QFN - 16
Temp. Range
E : -20 to 70 C
Handling Code
TU : Tube TR : Tape & Reel
TY : Tray (for QFN only)
Lead Free Code
L : Lead Free Device Blank : Original Device
Copyright
ANPEC Electronics Corp.
Rev. A.2 - Jun., 2006
APW7068
www.anpec.com.tw
3
Block Diagram
GND
Gate Control
Soft Start
and
Fault
Logic
Power-On
Reset
PHASE
LGATE
FB
VCC12
UGATE
V
REF
135%V
REF
O.C.P
Comparator
PWM
Comparator
O.V.P
Comparator
X1.35
COMP
BOOT
V
REF
50%V
REF
:
2
FBL
DRIVE
Oscillator
FS_DIS
U.V.P
Comparator
PGND
I
OCSET
40uA
OCSET
Regulator
10V
V
REF
(0.8V)
10V
Error
Amp 1
Error
Amp 2
Sawtooth Wave
(300KHz)
Reference
Buffer
REF_OUT
Sense Low Side
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
VCC12
VCC12 to GND
-0.3 to +16
V
BOOT
BOOT to PHASE
-0.3 to +16
V
UGATE
UGATE to PHASE <400ns pulse width
>400ns pulse width
-5 to BOOT+5
-0.3 to BOOT+0.3
V
LGATE
LGATE to PGND
<400ns pulse width
>400ns pulse width
-5 to VCC12+5
-0.3 to VCC12+0.3
V
PHASE
PHASE to GND <400ns pulse width
>400ns pulse width
-5 to +21
-0.3 to 16
V
DRIVE
DRIVE to GND
12
V
FB, FBL, COMP,
FS_DIS
FB, FBL, COMP, FS_DIS to GND
-0.3 to 7
V
Copyright
ANPEC Electronics Corp.
Rev. A.2 - Jun., 2006
APW7068
www.anpec.com.tw
4
Absolute Maximum Ratings (Cont.)
Symbol
Parameter
Rating
Unit
VCC12
IC Supply Voltage
10.8 to 13.2
V
V
IN1
Converter Input Voltage
2.9 to 13.2
V
V
OUT1
Converter Output Voltage
0.9 to 5
V
I
OUT1
Converter Output Current
0 to 30
A
I
OUT2
Linear Output Current
0 to 3
A
T
A
Ambient Temperature Range
-20 to 70
C
T
J
Junction Temperature Range
-20 to 125
C
Recommended Operating Conditions
Unless otherwise specified, these specifications apply over VCC12=12V, and T
A
=-20~70
C. Typical values
are at T
A
=25
C.
Electrical Characteristics
APW7068
Symbol
Parameter
Test Conditions
Min
Typ
Max
Unit
INPUT SUPPLY CURRENT
VCC12 Supply Current
(Shutdown mode)
UGATE, LGATE and DRIVE
open; FS_DIS=GND
4
6
mA
I
CC12
VCC12 Supply Current
UGATE, LGATE and DRIVE
open
8
12
mA
POWER-ON RESET
Rising VCC12 Threshold
7.7
7.9
8.1
V
Falling VCC12 Threshold
7.2
7.4
7.6
V
OSCILLATOR
Accuracy
-15
+15
%
F
OSC
Oscillator Frequency
255
300
345
KHz
V
OSC
Ramp Amplitude
(nominal 1.2V to 2.7V)
(NOTE3)
1.5
V
Duty
Maximum Duty Cycle
89
%
Symbol
Parameter
Rating
Unit
PGND
PGND to GND
-0.3 to +0.3
V
T
J
Junction Temperature Range
-20 to +150
C
T
STG
Storage Temperature
-65 ~ 150
C
T
SDR
Soldering Temperature (10 Seconds)
300
C
V
ESD
Minimum ESD Rating
2
KV
NOTE1: 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.
NOTE2: The device is ESD sensitive. Handling precautions are recommended.
Copyright
ANPEC Electronics Corp.
Rev. A.2 - Jun., 2006
APW7068
www.anpec.com.tw
5
Unless otherwise specified, these specifications apply over VCC12=12V, and T
A
=-20~70
C. Typical values
are at T
A
=25
C.
Electrical Characteristics (Cont.)
APW7068
Symbol
Parameter
Test Conditions
Min
Typ
Max
Unit
REFERENCE
V
REF
Reference Voltage
for Error Amp1 and Amp2
0.792 0.80 0.808
V
Reference Voltage Tolerance
-1
+1
%
PWM Load Regulation
I
OUT1
=0 to 10A
1
%
Linear Load Regulation
I
OUT2
=0 to 3A
1
%
PWM ERROR AMPLIFIER
Gain
Open Loop Gain
R
L
=10k, C
L
=10pF (NOTE3)
93
dB
GBWP Open Loop Bandwidth
R
L
=10k, C
L
=10pF (NOTE3)
20
MHz
SR
Slew Rate
R
L
=10k, C
L
=10pF (NOTE3)
8
V/us
FB Input Current
V
FB
=0.8V
0.1
1
uA
V
COMP
COMP High Voltage
5
V
V
COMP
COMP Low Voltage
0
V
I
COMP
COMP Source Current
COMP=2V
12
mA
I
COMP
COMP Sink Current
COMP=2V
12
mA
GATE DRIVERS
I
UGATE
Upper Gate Source Current
2.5
A
I
UGATE
Upper Gate Sink Current
BOOT=12V,
UGATE-PHASE = 2V
2
A
I
LGATE
Lower Gate Source Current
2.5
A
I
LGATE
Lower Gate Sink Current
VCC12=12V, LGATE=2V
3.5
A
R
UGATE
Upper Gate Source Impedance BOOT=12V, I
UGATE
=0.1A
2.25 3.375
R
UGATE
Upper Gate Sink Impedance
BOOT=12V, I
UGATE
=0.1A
0.7
1.05
R
LGATE
Lower Gate Source Impedance VCC12=12V, I
LGATE
=0.1A
2.25 3.375
R
LGATE
Lower Gate Sink Impedance
VCC12=12V, I
LGATE
=0.1A
0.4
0.6
T
D
Dead Time
20
nS
LINEAR REGULATOR
Gain
Open Loop Gain
R
L
=10k, C
L
=10pF (NOTE3)
70
dB
GBWP Open Loop Bandwidth
R
L
=10k, C
L
=10pF (NOTE3)
19
MHz
SR
Slew Rate
R
L
=10k, C
L
=10pF (NOTE3)
6
V/us
FBL Input Current
V
FBL
=0.8V
0.1
1
uA
V
DRIVE
DRIVE High Voltage
10
V
V
DRIVE
DRIVE Low Voltage
0
V
I
DRIVE
DRIVE Source Current
DRIVE=5V
4
mA
I
DRIVE
DRIVE Sink Current
DRIVE=5V
3
mA
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