®
SP6654
Ideal for portable designs powered with Li Ion battery
High Efficiency 800mA Synchronous Buck Regulator
FEATURES
■
Ultra-low 20µA Quiescent Current
■
98% Efficiency Possible
■
800mA Output Current
■
2.7V to 5.5V Input Voltage Range
■
Output Adjustable Down to 1.0V
■
No External FET’s Required
■
1.25A Inductor Peak Current Limit
■
100% Duty Ratio Low Dropout Operation
■
80µA Light Load Quiescent Current
in Dropout
■
Logic Shutdown Control
■
Programmable UVLO
■
Small 10pin MSOP Package
■
Power Good Indicator
■
Industry Standard 10 Pin MSOP and
and Small DFN Package
PV
IN
V
IN
PWR
GD
D1
D0
1
2
3
4
5
10
LX
SP6654
10 Pin DFN
9
P
GND
8
GND
7
V
OUT
6
FB
Now Available in Lead Free Packaging
APPLICATIONS
■
PDA's
■
DSC's
■
MP3 Players
■
USB Devices
■
Point of Use Power
DESCRIPTION
The SP6654 is a 800mA synchronous buck regulator which is ideal for portable applications that
use a Li-Ion or 3 cell alkaline/NiCD/NiMH input. The SP6654’s proprietary control loop, 20µA light
load quiescent current, and 0.3Ω power switches provide excellent efficiency across a wide range
of output currents. As the input battery supply decreases towards the output voltage the SP6654
seamlessly transitions into 100% duty ratio operation further extending useful battery life. The
SP6654 is protected against overload and short circuit conditions with a precise inductor peak
current limit. Other features include programmable under voltage lockout, externally pro-
grammed output voltage down to 1.0V, logic level shutdown control, and an open drain power
good indicator when V
OUT
is above 94% of its programmed value.
TYPICAL APPLICATION SCHEMATIC
2.7V to 5.5V Input
VI
L1
10µH
10Ω
R
VIN
CV
IN
1µF
V
OUT
800mA
VO
C
IN
22µF
1M
SP6654
P
VIN
V
IN
PWR
GD
LX
P
GND
GND
V
OUT
FB
C
OUT
22µF
CF
R
F
22pF
PWR
GD
D1
D0
D1
D0
R
I
200K
Date: 05/25/04
SP6654 High Efficiency 800mA Synchronous Buck Regulator
© Copyright 2004 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
PV
IN
,V
IN
.............................................................................................. 6V
All other pins .............................................................. -0.3V to V
IN
+0.3V
PV
IN
, P
GND
, LX current ........................................................................ 2A
Storage Temperature .................................................. -65
°C
to 150
°C
Operating Temperature ................................................. -40°C to +85°C
Lead Temperature (Soldering, 10 sec) ....................................... 300
°C
These are stress ratings only and functional operation of the device at
these ratings or any other above those indicated in the operation
sections of the specifications below is not implied. Exposure to
absolute maximum rating conditions for extended periods of time may
affect reliability.
ELECTRICAL CHARACTERISTICS
V
IN
=PV
IN
=V
SDN
=3.6V, V
OUT
=V
FB
, I
O
= 0mA, T
AMB
= -40°C to +85°C, The
♦
denotes the specifications wich apply over
the full operating temperature range, unless otherwise specified.
PARAMETER
Input Voltage Operating
Minimum Output Voltage
FB Set Voltage, Vr
MIN
UVLO
1.0
0.784
0.800
0.816
±4
Overall Accuracy
±5
On-Time Constant - KON Min,
TON=KON/(VIN-VOUT)
Off-Time Min,
TOFF=KOFF/VOUTConstant -
KOFF
Off-Time Blanking
PMOS Switch Resistance
NMOS Switch Resistance
Inductor Current Limit
LX Leakage Current
1.0
1.5
2.25
3.0
V*µs
%
♦
TYP
MAX
5.5
UNITS
V
V
V
♦
♦
CONDITIONS
Result of IQ measurement at
VIN=PVIN=5.5V
FB Set Voltage, Vr
25° C, IO=200mA Close Loop.
LI = 10µH,
Measured at VIN=5.5V, no
load, TAMB = 0° C to 70° C
Measured at VIN=3.6V, 200mA
load, Close Loop
Close Loop, LI = 10µH, COUT
= 22µF
Inductor current limit tripped,
VFB=0.5V Measured at VOUT
= 2V
T
AMB
=27° C
♦
1.6
2.4
100
0.3
0.3
1.25
0.01
96
3.2
ns
0.6
0.6
1.50
3
V*µs
♦
Ω
Ω
A
µA
♦
♦
♦
♦
IPMOS = 200mA
INMOS = 200mA
VFB=0.5V
D0=D1=0
VOUT=2.5V, IO=200mA
T
AMB
=27° C
Power Efficiency
92
Minimum Guaranteed Load Current
VIN Quiescent Current
VIN Shutdown Current
VOUT Quiescent Current
VOUT Shutdown Current
2.55
UVLO Undervoltage Lockout
Threshold, VIN falling
2.70
2.85
UVLO hysteresis
PWRGD Low Output Voltage
PWRGD Leakage Current
PWRGD Rising Threshold
PWRGD Hysterisis
D1,D0 Leakage Current
0.60
D1,D0 Input Threshold Voltage
1.25
FB Leakage Current
1
1.8
100
-6
80
1
0.90
500
800
900
20
1
2
1
2.70
2.85
3.00
40
0.4
1
30
500
5
500
2.85
3.00
3.15
%
VOUT=3.3V, IO=800mA
T
AMB
=27° C
mA
µA
nA
µA
nA
♦
♦
♦
♦
♦
♦
VOUT=3.3V, VIN=3.6V and
VIN= 5.5V
D1=D0=0V
VOUT = 3.3V
D1=D0=0V
D1=0V, D0=VIN
D1=VIN, D0=0V
D1=VIN, D0=VIN
T
AMB
=27° C
V
♦
♦
mV
V
µA
%
mV
nA
♦
♦
♦
♦
VIN=3.3V, ISINK=1mA
VPWRGD =3.6V
FB Set Voltage -6%,
T
AMB
=27° C
T
AMB
=27° C
High to Low Transition
Low to High Transition
FB=1V
V
♦
nA
Date: 05/25/04
SP6654 High Efficiency 800mA Synchronous Buck Regulator
© Copyright 2004 Sipex Corporation
2
PIN DESCRIPTION
PIN NUMBER
1
2
3
PIN NAME
PV
IN
V
IN
PWR
GD
DESCRIPTION
Input voltage power pin. Inductor charging current passes through this pin.
Internal supply voltage. Control circuitry powered from this pin.
Open drain Power Good indicator. If V
FB
is less than 750mV this pin is
pulled to ground. When V
FB
is above 750mV this pin is open. Connect
a resistor from this pin to V
IN
or V
OUT
to create a logic signal.
Digital mode control input. See table I for definition.
Digital mode control input. See table I for definition.
External feedback network input connection. Connect a resistor from
FB to ground and FB to V
OUT
to set the output voltage. This pin
regulates to the internal bandgap reference voltage of 0.8V.
Output voltage sense pin. Used by the timing circuit to set minimum on
and off times.
Internal ground pin. Control circuitry returns current to this pin.
Power ground pin. Synchronous rectifier current returns through this pin.
Inductor switching node. Inductor tied between this pin and the output
capacitor to create regulated output voltage.
4
5
6
D1
D0
FB
7
8
9
10
V
OUT
GND
P
GND
LX
D1
0
0
1
1
D0
0
1
0
1
Shutdown. All internal circuitry is disabled and the power switches are opened.
Device enabled, falling UVLO threshold =2.70V
Device enabled, falling UVLO threshold =2.85V
Device enabled, falling UVLO threshold =3.00V
Table 1. Operating Mode Definition
FUNCTIONAL DIAGRAM
Vin
DRVON
VOLOW
TONOVER
MIN Ton
Internal Supply
TONOVER
REF
+
V
OUT
PV
IN
Min Ton
Min Ton =
K
ON
/(V
IN
-V
OUT
)
M
DRVON
R
S
Q
1
OVR_I
Vos
-
REF'
+
-
VOLOW
+
DRIVER
C
ILIM/M
-
C
V
RAMP
_
Q
FB
+
-
FB'
RST
OVR_I
LX
DRVON
REF
Ref
Block
UVLO
TSD
D0
D1
+
One-Shot
=100ns
BLANK
-
C
Zero_X
P
GND
T
OFF
=
K
OFF
/V
OUT
ILIM/M
OVR_I
750mV
GND
+
-
C
PWR
GD
DRVON
BLANK
BLANK = Tblank(=100ns) or Toff = Koff/Vout
FB
UVLO
Date: 05/25/04
SP6654 High Efficiency 800mA Synchronous Buck Regulator
© Copyright 2004 Sipex Corporation
3
TYPICAL PERFORMANCE CHARATERISTICS
Refer to the typical application schematic, T
AMB
= +27°C
100
95
90
100
95
90
Efficiency (%)
Vi=3.6V
Vi=3.9V
Vi=4.2V
Vi=5.0V
1.0
10.0
ILoad (mA)
100.0
1000.0
Efficiency (%)
85
80
75
70
65
60
0.
85
80
75
70
65
60
0.1
Vi=3.6V
Vi=3.9V
Vi=4.2V
Vi=5.0V
1.0
10.0
ILoad (mA)
100.0
1000.0
Figure 1. Efficiency vs Load, V
OUT
= 3.3V
Figure 2. Efficiency vs Load, V
OUT
= 1.5V
3.40
Vi=3.6V
Vi=3.9V
Vi=4.2V
Vi=5.0V
1.55
Vi=3.6V
Vi=3.9V
Vi=4.2V
Vi=5.0V
3.35
Vout (V)
1.53
1.51
3.30
Vout (V)
1.49
3.25
1.47
3.20
0
200
400
600
ILoad (mA)
800
1000
1.45
0
200
400
600
800
1000
ILoad (mA)
Figure 3. Line/Load Rejection, V
OUT
= 3.3V
Figure 4. Line/Load Rejection, V
OUT
= 1.5V
500
Tamb = 85°C
Tamb = 25°C
Tamb = -40°C
400
50
Tamb = 85°C
Tamb = 25°C
Tamb = -40°C
40
Iin (uA)
Iin (µA)
300
30
200
20
100
10
0
3.0
3.3
3.6
Vin (V)
3.9
4.2
0
3.0
3.3
3.6
Vin (V)
3.9
4.2
Figure 5. No Load Battery Current, V
OUT
=3.3V
Figure 6. No Load Battery Current, V
OUT
=1.5V
Date: 05/25/04
SP6654 High Efficiency 800mA Synchronous Buck Regulator
© Copyright 2004 Sipex Corporation
4
TYPICAL PERFORMANCE CHARATERISTICS: Continued
Refer to the typical application schematic, T
AMB
= +27°C
3.5
3.0
2.5
3.5
3.0
2.5
Kon (V*usec)
Kon (V*usec)
2.0
1.5
1.0
0.5
0.0
3.6
2.0
1.5
1.0
0.5
3.9
4.2
4.5
Vin (V)
4.8
5.1
5.4
0.0
3.0
3.3
3.6
3.9
4.2 4.5
Vin (V)
4.8
5.1
5.4
Figure 7. K
ON
vs V
IN
, V
OUT
=3.3V
Figure 8. K
ON
vs V
IN
, V
OUT
=1.5V
3.5
3.0
2.5
Koff (V*usec)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
3.6
Koff (V*usec)
2.0
1.5
1.0
0.5
3.9
4.2
4.5
Vin (V)
4.8
5.1
5.4
0.0
3.0
3.3
3.6
3.9
4.2
Vin (V)
4.5
4.8
5.1
5.4
Figure 9. K
OFF
vs V
IN
, V
OUT
=3.3V
Figure 10. K
OFF
vs V
IN
, V
OUT
=1.5V
700.0
700.0
600.0
600.0
500.0
500.0
Frequency (KHz)
400.0
Frequency (KHz)
400.0
300.0
300.0
200.0
Vout = 3.3V
Measured
Vout = 3.3V
Calculated
4.0
Vin (V)
4.5
5.0
200.0
Vout = 1.5V
Measured
Vout = 1.5V
Calculated
3.4
3.8
4.2
Vin (V)
4.6
5.0
100.0
100.0
0.0
3.5
0.0
Figure 11. Ripple Frequency vs. V
IN
, I
OUT
=600mA,
V
OUT
=3.3V
Date: 05/25/04
Figure 12. Ripple Frequency vs. V
IN
, I
OUT
=600mA,
V
OUT
=1.5V
© Copyright 2004 Sipex Corporation
SP6654 High Efficiency 800mA Synchronous Buck Regulator
5
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