APW7068
Synchronous Buck PWM and Linear Controller
with 0.8V Reference Out Voltage
Features
•
Two Regulated Voltages and REF_OUT
- Synchronous Buck Converter
- Linear Regulator
- REF_OUT = 0.8V±1% 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’ R
DS(ON)
s
SOP-14, QSOP-16 and Compact 4mmx4mm
Thin QFN-16 packages
Lead Free Available (RoHS Compliant)
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 V
CC12
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’ R
DS(ON)
, comparing with the voltage of OCSET
s
pin. When the output current reaches the trip point, the
controller will shutdown the IC directly, and latch the
converter’ output. The Under-Voltage Protection (UVP)
s
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.
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Typical Application Circuit
12V
V
IN2
Q4
V
OUT2
Linear
Controller
PWM
Controller
V
IN1
Q1
L
Q2
V
OUT1
Applications
•
Graphic Cards
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 - Nov., 2006
1
www.anpec.com.tw
APW7068
Absolute Maximum Ratings (Cont.)
Symbol
V
PGND
T
J
T
STG
T
SDR
V
ESD
PGND to GND
Junction Temperature Range
Storage Temperature
Soldering Temperature (10 Seconds)
Minimum ESD Rating
Parameter
Rating
-0.3 to +0.3
-20 to +150
-65 ~ 150
300
±2
Unit
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.
Note 2: The device is ESD sensitive. Handling precautions are recommended.
Recommended Operating Conditions
Symbol
V
CC12
V
IN1
V
OUT1
I
OUT1
I
OUT2
T
A
T
J
IC Supply Voltage
Converter Input Voltage
Converter Output Voltage
Converter Output Current
Linear Output Current
Ambient Temperature Range
Junction Temperature Range
Parameter
Rating
10.8 to 13.2
2.9 to 13.2
0.9 to 5
0 to 30
0 to 3
-20 to 70
-20 to 125
Unit
V
V
V
A
A
°C
°C
Electrical Characteristics
Unless otherwise specified, these specifications apply over V
CC12
= 12V, and T
A
=-20 ~ 70°C. Typical values are at T
A
= 25°C.
Symbol
Parameter
Test Conditions
APW7068
Min
Typ
Max
Unit
INPUT SUPPLY CURRENT
I
CC12
VCC12 Supply Current
(Shutdown mode)
VCC12 Supply Current
POWER-ON RESET
Rising VCC12 Threshold
Falling VCC12 Threshold
OSCILLATOR
Accuracy
F
OSC
V
OSC
Duty
V
REF
Oscillator Frequency
Ramp Amplitude
Maximum Duty Cycle
Reference Voltage
Reference Voltage Tolerance
PWM Load Regulation
Linear Load Regulation
PWM ERROR AMPLIFIER
Gain
GBWP
Open Loop Gain
Open Loop Bandwidth
R
L
= 10k, C
L
= 10pF
(Note 3)
R
L
= 10k, C
L
= 10pF
(Note 3)
UGATE, LGATE and DRIVE open;
FS_DIS = GND
UGATE, LGATE and DRIVE open
7.7
7.2
-15
255
(nominal 1.2V to 2.7V)
(Note 3)
4
8
7.9
7.4
6
12
8.1
7.6
+15
mA
mA
V
V
%
kHz
V
%
300
1.5
89
345
REFERENCE
for Error Amp1 and Amp2
I
OUT1
= 0 to 10A
I
OUT2
= 0 to 3A
93
20
0.792
-1
0.80
0.808
+1
1
1
V
%
%
%
dB
MHz
Copyright
©
ANPEC Electronics Corp.
Rev. A.3 - Nov., 2006
3
www.anpec.com.tw
APW7068
Electrical Characteristics (Cont.)
Unless otherwise specified, these specifications apply over V
CC12
= 12V, and T
A
=-20 ~ 70°C. Typical values are at T
A
= 25°C.
Symbol
Parameter
Test Conditions
APW7068
Min
Typ
8
0.1
5
0
V
COMP
= 2V
V
COMP
= 2V
12
12
2.5
2
2.5
3.5
2.25
0.7
2.25
0.4
20
R
L
= 10k, C
L
= 10pF
(Note 3)
R
L
= 10k, C
L
= 10pF
V
FBL
= 0.8V
(Note 3)
Max
Unit
PWM ERROR AMPLIFIER (Cont.)
SR
V
COMP
V
COMP
I
COMP
I
COMP
I
UGATE
I
UGATE
I
LGATE
I
LGATE
R
UGATE
R
UGATE
R
LGATE
R
LGATE
T
D
Gain
GBWP
SR
V
DRIVE
V
DRIVE
I
DRIVE
I
DRIVE
V
FB-OV
V
FBL-UV
I
OCSET
T
SS
REF_OUT
V
REF_OUT
I
REF_OUT
Output Voltage
Offset Voltage
Source Current
Sink Current
Output Capacitance
Note 3: Guaranteed by design.
Slew Rate
FB Input Current
COMP High Voltage
COMP Low Voltage
COMP Source Current
COMP Sink Current
Upper Gate Source Current
Upper Gate Sink Current
Lower Gate Source Current
Lower Gate Sink Current
Upper Gate Source Impedance
Upper Gate Sink Impedance
Lower Gate Source Impedance
Lower Gate Sink Impedance
Dead Time
Open Loop Gain
Open Loop Bandwidth
Slew Rate
FBL Input Current
DRIVE High Voltage
DRIVE Low Voltage
DRIVE Source Current
DRIVE Sink Current
R
L
= 10k, C
L
= 10pF
(Note 3)
V
FB
= 0.8V
V/us
1
uA
V
V
mA
mA
A
A
A
A
3.375
1.05
3.375
0.6
Ω
Ω
Ω
Ω
nS
dB
MHz
V/us
1
uA
V
V
mA
mA
%
%
44
uA
ms
0.808
+8
V
mV
mA
mA
2.2
uF
GATE DRIVERS
V
BOOT
= 12V,
V
UGATE
- V
PHASE
= 2V
V
CC12
= 12V, V
LGATE
= 2V
V
BOOT
= 12V, I
UGATE
= 0.1A
V
BOOT
= 12V, I
UGATE
= 0.1A
V
CC12
= 12V, I
LGATE
= 0.1A
V
CC12
= 12V, I
LGATE
= 0.1A
LINEAR REGULATOR
70
19
6
0.1
10
0
V
DRIVE
= 5V
V
DRIVE
= 5V
4
3
135
50
36
F
OSC
=300kHz
0.792
-8
1.5
0.25
0.4
3
0.5
1
40
8.5
0.800
R
L
= 10k, C
L
= 10pF
(Note 3)
PROTECTION
FB Over Voltage Protection Trip Point Percent of V
REF
FBL Under Voltage Protection Trip
Point
OCSET Current Source
Internal Soft-Start Interval
(NOTE3)
Percent of V
REF
SOFT START
Copyright
©
ANPEC Electronics Corp.
Rev. A.3 - Nov., 2006
4
www.anpec.com.tw
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