APW7093
3A, 1MHz, Step Down DC/DC Regulator
Features
•
•
•
•
Source/Sink 3A
Up to 1MHz Switches Frequency
Up to 94% Efficiency
Internal PMOS/NMOS Switches
- 70mΩ/40mΩ On-Resistance at V
IN
= 4.5V
- 90mΩ/60mΩ On-Resistance at V
IN
= 3V
General Description
The APW7093 is a reversible energy flow, constant-
off-time, pulse-width modulated (PWM), step-down
DC-DC converter. It is ideal for use in notebook and
sub-notebook computers that require 1.1V to 5V
active termination power supplies. This device features
an internal PMOS power switch and internal
synchronous rectifier for high efficiency and reduced
component count. The internal 90m
Ω
PMOS power
switch and 60m
Ω
NMOS synchronous-rectifier switch
easily deliver continuous load currents up to 3A. The
APW7093 accurately tracks an external reference
voltage, produces an adjustable output from 1.1V to
VIN, and achieves efficiencies as high as 94%.
The APW 7093 uses a unique current-mode,
constant-off-time, PWM control scheme that allows
the output to source or sink current. This feature
allows energy to return to the input power supply that
otherwise would be wasted. The programmable
constant-off-time architecture sets switching frequencies
up to 1MHz, allowing the user to optimize performance
trade-offs between efficiency, output switching noise,
component size, and cost. The APW7093 features an
adjustable soft-start to limit surge currents during
startup, a 100% duty-cycle mode for low-dropout
operation, and a low-power shutdown mode that disables
the power switches and reduces supply current below
1µA. The APW7093 is available in a 32-pin QFN with
an exposed backside pad or a 16-pin SSOP.
•
•
•
•
•
•
±1% Output Accuracy
1.1V to V
IN
Adjustable Output Voltage
3V to +5.5V Input Voltage Range
<1µA Shutdown Supply Current
Programmable Constant-Off-Time Operation
Thermal Shutdown
•
Adjustable Soft-Start Inrush Current Limiting
•
Output Short-Circuit Protection
•
Lead Free Available (RoHS Compliant)
Applications
•
•
•
•
•
•
•
Motherboard
Graphics Cards
Cable or DSL Modems, Set Top Boxes
DSP Supplies
Memory Supplies
5V Input DC-DC Regulators
Distributed Power Supplies
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.5 - Jun., 2005
1
www.anpec.com.tw
APW7093
Pin Description
SHDN
N.C
N.C
N.C
LX
LX
32
1
N.C
IN
LX
IN
N.C
SS
N.C
EXTREF
8
TOFF
N.C
N.C
N.C
GND
REF
N.C
FB
APW7093
PGND
N.C
VCC
GND
17
N.C
N.C
25
24
PGND
PGND
LX
LX
SHDN
IN
LX
IN
SS
EXTREF
TOFF
FB
1
2
3
4
16
15
14
LX
PGND
LX
PGND
VCC
GND
REF
GND
13
APW7093
12
5
6
7
8
11
10
9
9
16
SSOP - 16
QFN - 32
Ordering and Marking Information
APW7093
Lead Free Code
Handling Code
Temp. Range
Package Code
APW7093 N :
APW7093
XXXXX
Package Code
N : SSOP-16
QA : QFN -32
Operating Ambient Temp. Range
I : -45 to 85
°
C
Handling Code
TU : TubeTR : Tape & Reel
Lead Free Code
L : Lead Free Device Blank : Original Device
XXXXX - Date Code
APW7093 QA :
APW7093
XXXXX
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 soldiering
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.
Copyright
©
ANPEC Electronics Corp.
Rev. A.5 - Jun., 2005
2
www.anpec.com.tw
APW7093
Block Diagram
0.01
µ
F
V
IN
SS
V
C C
FB
IN
CURRENT
SENSE
C
IN
V
IN
+3.0V TO +5.5V
EXTREF
+
_
SHDN
REF
PWM
LOGIC
AND
DRIVERS
LX
L
C
O U T
REF
TIMER
GND
R
TOFF
PGND
Fig1. Block Diagram
Absolute Maximum Ratings
Parameter
V
CC
to GND
IN to V
CC
GND to PGND
Rating
-0.3 ~ +6
±0.3
±
0.3
-0.3 ~ V
CC
+0.3
-0.3 ~ V
IN
-1.7
1.6
1
-3.5 ~ +4.1
-40 ~ +85
+150
-65~+150
+300
Unit
V
V
V
V
V
W
W
A
°C
°C
°C
°C
SHDN
, SS, FB, T
OFF,
V
REF
to GND
EXTREF to GND
Power dissipation; Part mount on 1in
2
of 1oz copper; QFN-28
Power dissipation; Part mount on 1in
2
of 1oz copper; SSOP-16
LX Current
Operating Temperature Range
Junction Temperature
Storage Temperature Range
Lead Temperature (soldering,10s)
Recommend Operating Condition
Recommend Operating Condition
Symbol
Parameter
V
IN
Input Voltage Range
V
OUT
Output Voltage Range
C
OUT
Output Capacitor
C
IN
Input Capacitor
L
Inductor
R
TOFF
Programmed off-time Resistance
MIN
3
1.1
220
22
0.56
–
TYP
MAX
5.5
V
IN
UNIT
V
V
uF
uF
uH
KΩ
NOTE
V
EXTREF
<= V
IN
-1.7V
Low ESR Capacitor
Refer to Application section
for further Information.
www.anpec.com.tw
330
33
1
–
–
Copyright
©
ANPEC Electronics Corp.
Rev. A.5 - Jun., 2005
3
APW7093
Electrical Characteristics
(V
IN
=V
CC
=3.3V, V
EXTREF
=+1.1V, T
A
=-45 to +85
o
C, unless otherwise noted, Typical values are at T
A
=+25
o
C.)
Symbol
Parameter
Test Conditions
APW7093
Min Typ Max
3.0
V
IN
=V
CC
=+3.0V to +5.5V,
I
LOAD
=0,V
EXTREF
=1.25V (Note2)
I
LOAD
=-3A to +3A, V
EXTREF
=+1.25V
V
REF
-
0.01
-12
20
V
IN
-
1.7
5.5
+12
Unit
V
mV
mV
V
V
mV
mΩ
m
Ω
A
MHz
mA
15
µA
°C
2.7
250
V
nA
µ
s
µs
µ
s
5
6
µ
A
mA
+1
0.8
SHDN Logic Levels
2.0
µA
V
V
IN
, V
CC
Input Voltage
Feedback Voltage Accuracy
(V
FB
–V
EXTREF
)
∆
V
FB
Feedback Load Regulation Error
V
EXTREF
External Reference Voltage Range V
IN
=V
CC
=+3.0 to +5.5V
V
REF
Reference Voltage
Reference Load Regulation
R
PMOS
R
NMOS
I
LIMIT
f
SW
I
CC
I
IN
I
SHDN
PMOS Switch On-Resistance
NMOS Switch On-Resistance
Current Limit Threshold
Switching Frequency
No Load Supply Current
Shutdown Supply Current
Thermal Shutdown Threshold
UVLO
I
FB
Under Voltage Lockout Threshold
FB Input Current
I
REF
= -1µA to +10µA
I
LX
=0.5A
I
LX
=0.5A
V
IN
> V
LX
(Note3)
V
IN
=+4.5V
V
IN
=+3.0V
V
IN
=+4.5V
V
IN
=+3.0V
1.07 1.10 1.12
8
0
2
0.3
70
90
50
60
3.5
4.1
2
140
180
100
120
4.7
1
1
32
<1
150
2.5
0
2.6
60
f
SW
=500kHz
f
SW
=500kHz
SHDN = GND, I
CC
+ I
IN
Hysteresis =15°C
V
CC
falling, hysteresis = 90mV
V
FB
=V
EXTREF
+0.1V
R
TOFF
=30.1k
Ω
0.40 0.44 0.48
1.10 1.20 1.30
4.3
4.8
4×TOFF
5.3
T
OFF
Off-Time
R
TOFF
=110kΩ
R
TOFF
=499kΩ
Startup Off-Time
T
ON
I
SS
I
SS
On-Time
SS Source Current
SS Sink Current
SHDN Input Current
V
IL
V
IH
I
OUT(RMS)
Maximum Output RMS Current
Copyright
©
ANPEC Electronics Corp.
Rev. A.5 - Jun., 2005
4
(Note3)
0.34
4
V
SS
=1V
V
SHDN
=0, V
CC
2
-1
3.1 A
RMS
www.anpec.com.tw
APW7093
Electrical Characteristics (Cont.)
(V
IN
=V
CC
=3.3V, V
EXTREF
=+1.1V, T
A
= -45 to +85
o
C, unless otherwise noted, Typical values are at T
A
=+25
o
C.)
Symbol
V
IL
V
IH
SHDN Logic Levels
2.0
I
OUT(RMS)
Maximum Output RMS Current
Parameter
Test Conditions
APW7093
Min Typ Max
0.8
Unit
V
3.1 A
RMS
Note2: The output voltage will have a DC-regulation level lower than the feedback error comparator threshold
by 50% of the ripple.
Note3: Recommended operating frequency, not production tested.
Functional Pin Description
Name
N.C
IN
PIN (QFN)
1,5,7,9,11,13,16,19,
25,26,28,30,32
2,4
PIN (QSOP)
X
2,4
FUNCTION
No Connection, Not internally connected.
Supply Voltage Input for the internal PMOS Power Switch.
Not internally connected. Externally connect all pins for
proper operation.
Inductor Connection. Connection for the drains of the PMOS
power switch and NMOS synchronous-rectifier switch.
Connect the inductor from this node to the output filter
capacitor and load. Not internally connected. Externally
connect all pins for proper operation.
Soft-Start Connect a capacitor from SS to GND to limit inrush
current during startup.
External Reference Input Feedback input regulates to
V
EXTREF
. The PWM controller remains off until EXTREF is
greater than REF.
Off-Time Select Input. Sets the PMOS power switch
constant-off-time. Connect a resistor from TOFF to GND to
adjust the PMOS switch off-time.
Feedback Input. Connect directly to output for fixed-voltage
operation or to a resistive-divider for adjustable operating
modes.
Analog Ground. Connect exposed backside pad and corner
tabs to analog GND.
Reference Output. Bypass REF to GND with a 0.1
µ
F
capacitor.
Tie to GND (pin 13 QFN; pin 9 SSOP)
Analog Supply Voltage Input. Supplies internal analog
circuitry. Bypass V
CC
with a 10
Ω
and 1
µ
F low-pass filter. See
Figure2.
Power Ground. Internally connected to the internal NMOS
synchronous-rectifier switch.
Shutdown control Input Drive SHDN low to disable the
reference, control circuitry, and internal MOSFETs. Drive
high or connect to V
CC
for normal operation.
5
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LX
3,21,22,27,29
3,14,16
SS
EXTREF
6
8
5
6
T
OFF
10
7
FB
GND
REF
GND
V
CC
PGND
SHDN
12
14,17,backside pad,
corner tabs
15
17
18
20,23,24
31
8
9
10
11
12
13,15
1
Copyright
©
ANPEC Electronics Corp.
Rev. A.5 - Jun., 2005
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