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
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’ R
DS(ON)
,
s
comparing with the voltage of OCSET pin. When the out-
put current reaches the trip point, the controller will
•
•
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 QFN-16 packages
Lead Free Available (RoHS Compliant)
Applications
•
Graphic Cards
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.
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 - Jun., 2006
1
www.anpec.com.tw
APW7068
Absolute Maximum Ratings (Cont.)
Symbol
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
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.
Recommended Operating Conditions
Symbol
VCC12
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 VCC12=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
VCC12 Supply Current
(Shutdown mode)
VCC12 Supply Current
POWER-ON RESET
Rising VCC12 Threshold
Falling VCC12 Threshold
OSCILLATOR
Accuracy
F
OSC
V
OSC
Duty
Oscillator Frequency
Ramp Amplitude
Maximum Duty Cycle
4
I
CC12
UGATE, LGATE and DRIVE
open; FS_DIS=GND
UGATE, LGATE and DRIVE
open
7.7
7.2
4
8
6
12
mA
mA
7.9
7.4
8.1
7.6
V
V
-15
255
(nominal 1.2V to 2.7V)
(NOTE3)
300
1.5
89
+15
345
%
KHz
V
%
Copyright
©
ANPEC Electronics Corp.
Rev. A.2 - Jun., 2006
www.anpec.com.tw
APW7068
Electrical Characteristics (Cont.)
Unless otherwise specified, these specifications apply over VCC12=12V, and T
A
=-20~70°C. Typical values
are at T
A
=25
°
C.
Symbol
REFERENCE
V
REF
Parameter
Test Conditions
APW7068
Min
Typ
Max
Unit
Reference Voltage
Reference Voltage Tolerance
PWM Load Regulation
Linear Load Regulation
for Error Amp1 and Amp2
I
OUT1
=0 to 10A
I
OUT2
=0 to 3A
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
0.792 0.80 0.808
-1
+1
1
1
93
20
8
0.1
5
0
1
V
%
%
%
dB
MHz
V/us
uA
V
V
mA
mA
A
A
A
A
Ω
Ω
Ω
Ω
nS
dB
MHz
V/us
PWM ERROR AMPLIFIER
Gain
GBWP
SR
V
COMP
V
COMP
I
COMP
I
COMP
Open Loop Gain
Open Loop Bandwidth
Slew Rate
FB Input Current
COMP High Voltage
COMP Low Voltage
COMP Source Current
COMP Sink Current
COMP=2V
COMP=2V
BOOT=12V,
UGATE-PHASE = 2V
VCC12=12V, LGATE=2V
12
12
2.5
2
2.5
3.5
2.25 3.375
0.7
0.4
20
1.05
0.6
2.25 3.375
GATE DRIVERS
I
UGATE
Upper Gate Source Current
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
Upper Gate Sink Current
Lower Gate Source Current
Lower Gate Sink Current
Upper Gate Sink 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
Upper Gate Source Impedance BOOT=12V, I
UGATE
=0.1A
BOOT=12V, I
UGATE
=0.1A
VCC12=12V, I
LGATE
=0.1A
Lower Gate Source Impedance VCC12=12V, I
LGATE
=0.1A
LINEAR REGULATOR
R
L
=10k, C
L
=10pF (NOTE3)
R
L
=10k, C
L
=10pF (NOTE3)
R
L
=10k, C
L
=10pF (NOTE3)
V
FBL
=0.8V
70
19
6
0.1
10
0
DRIVE=5V
DRIVE=5V
4
3
1
uA
V
V
mA
mA
Copyright
©
ANPEC Electronics Corp.
Rev. A.2 - Jun., 2006
5
www.anpec.com.tw
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