1
Rev:001 Date:11/20/03
SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
SP6649
FEATURES
Ultra-low 12A Quiescent Current
700mA Output Current at 2.6V
IN,
3.3V
OUT
94% Efficiency Possible
Wide Input Voltage Range: 0.85V to 4.5V
3.3V Fixed Output and adjustable 2.5V to
5.0V Output Range
Internal Synchronous Rectifier for High
Efficiency
0.3 Charging Switch, 0.3 Synchro-
nous Rectifier
Anti-Ringing Inductor Switch
Programmable Inductor Peak Current
Logic Shutdown Control
Under Voltage Lock-Out, 0.62V
Programmable Low Battery Detect
Small 10 pin MSOP Package
Ultra-low Quiescent Current,
High Efficiency Boost DC-DC Regulator
APPLICATIONS
Digital Still Cameras
MP3 Players
PDA's
Pagers
Handheld Portable Devices
Medical Monitors
DESCRIPTION
The SP6649 is an ultra-low quiescent current, high efficiency step-up DC-DC converter ideal for
single and dual cell alkaline, or Li-Ion battery applications such as digital still cameras, PDA's,
MP3 players, and other portable devices. The SP6649 combines the high delivery associated
with PWM control, and the low quiescent current and excellent light-load efficiency of PFM control.
The SP6649 features 12A quiescent current, synchronous rectification, a 0.3 charging switch,
anti-ringing inductor switch, programmable low battery detect, under-voltage lockout and
programmable inductor peak current. The device can be controlled by a 1nA active LOW
shutdown pin.
1
2
3
4
5
10
9
8
7
6
V
BATT
LBI
LBON
R
LIM
SHDN
V
OUT
LX
P
GND
GND
FB
Top View
10 pin MSOP
Tja=113
C/W
+
C1
47uF
L1 10uH
VBATT
C3
47pF
LBI
SHDN
R1
205K
+
C2
47uF
RLIM
1.87K
3.3Vout
R2
124K
C4
1uF
SP6649
1
2
4
5
6
7
8
3
9
10
VBATT
LBI
RLIM
SHDN
FB
GND
PGND
LBON
LX
VOUT
LBON
C1 = C2 = Kemet T49C476K010AS, L1 = Sumida CDRH5D28-100
R1 = 374K for 5V
OUT
Figure 1. Typical Application Circuit
Figure 2. Maximum Load Current in Operation
TBD
2
Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
PARAMETER
MIN
TYP
MAX
UNITS
CONDITIONS
Input Voltage Operating Range, V
BATT
0.7
4.5
V
After Startup
Under Voltage Lock-out/UVLO
0.62
V
Start-up Input Voltage, V
BATT
0.85
0.9
V
R
LOAD
= 3k
Output Voltage, V
O
3.16
3.30
3.44
V
3.3V V
O
preset
Quiescent Current into V
O
, I
QO
12
22
A
V
OUT
= 3.3V, V
FB
= 1.5V, Toggle SHDN
Quiescent Current into V
BATT
, I
QB
20
500
nA
V
OUT
= 3.3V, V
FB
= 1.5V
Shutdown Current into V
O,
I
SDO
1
500
nA
V
SHDN
= 0V
Shutdown Current into V
BATT,
I
SDB
200
500
nA
V
SHDN
= 0V, V
BATT
= 2.6V
Efficiency, R
LIM
= 4.0K
85
%
V
BATT
= 1.3V, I
OUT
= 50mA
91
%
V
BATT
= 2.6V, I
OUT
= 100mA
Efficiency, R
LIM
= 1.87K
85
%
V
BATT
= 1.3V, I
OUT
= 100mA
92
%
V
BATT
= 2.6V, I
OUT
= 200mA
Inductor Current Limit, I
PK
1.0
1.2
1.4
A
R
LIM
= 1.17k , I
PK
= 1400/R
LIM
250
mA
V
BATT
= 1.3V, R
LIM
= 1.17k
Output Current
700
mA
V
BATT
= 2.6V, R
LIM
= 1.17k
150
mA
V
BATT
= 1.3V, R
LIM
= 1.87k
400
mA
V
BATT
= 2.6V, R
LIM
= 1.87k
Minimum Off-Time Constant K
OFF
1.1
V*s
t
OFF
K
OFF
/ (V
OUT
- V
BATT
)
Maximum On-Time Constant K
ON
3.3
V*s
t
ON
K
ON
/ V
BATT
N
MOS
Switch Resistance
0.30
0.6
I
NMOS
= 100mA
P
MOS
Switch Resistance
0.30
0.6
I
PMOS
= 100mA
FB Set Voltage, V
FB
1.20
1.25
1.30
V
External feedback
FB Input Current
1
100
nA
V
FB
=1.3V
LBI Falling Trip Voltage
0.594
0.625
0.656
V
LBI Hysteresis
25
mV
Low Output Voltage for LBON, V
OL
0.4
V
V
BATT
= 1.3V, Isink = 1mA
Leakage current for LBON
500
nA
V
BATT
= 1.3V, V
LBON
= 3.3V
SHDN Input Voltage
V
IL
0.25
V
BATT
= 1.3V
V
IH
1.0
V
V
BATT
= 1.3V
V
IL
0.5
V
BATT
= 2.6V
V
IH
2.0
V
BATT
= 2.6V
SHDN Input Current
1
100
nA
SPECIFICATIONS
V
BATT
=V
SHDN
= 1.3V, V
FB
=0V, I
LOAD
= 0mA, T
AMB
= -40C to +85C, V
OUT
= +3.3V, typical values at 27C unless otherwise
noted.
ABSOLUTE MAXIMUM RATINGS
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.
LX, Vo, V
BATT
, LBON, FB to GND pin ................................. -0.3 to 6.0V
SHDN, LBI ............................................................ -0.3V to V
BATT
+0.5V
Vo, GND, LX Current .................................................................... 1.3A
Reverse V
BATT
Current ............................................................... 220mA
Forward V
BATT
Current ............................................................... 500mA
Storage Temperature .................................................. -65 C to 150C
Operating Temperature ................................................ -40C to +85C
Lead Temperature (Soldering, 10 sec) ....................................... 300 C
ESD Rating ........................................................................... 2kV HBM
3
Rev:001 Date:11/20/03
SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
PIN DESCRIPTION
PIN NUMBER
PIN NAME
DESCRIPTION
1
V
BATT
Battery Voltage pin. The startup circuitry runs off of this pin. The
operate circuit also uses this voltage to regulate the off-time
[t
OFF
= K
OFF
/ (V
OUT
- V
BATT
)]. When the battery voltage drops below
0.62V after a successful startup the SP6649 goes into an undervoltage
lockout mode (UVLO).
2
LBI
Low Battery Input pin. LBI below 0.61V causes the LBON pin to pull
down to ground. Use a resistor divider to program the low voltage
threshold for each battery configuration.
3
LBON
Low Battery Output Not pin. Open drain N
MOS
output that sinks
current to ground when LBI is below 0.625V.
4
R
LIM
Resistor Programmable Inductor Peak Current. By connecting a
resistor R
LIM
from this pin to ground the inductor peak current is set by
I
PEAK
=1400/R
LIM
. The range for R
LIM
is 4.0K (for 350mA) to 1.17K
(for 1.2A).
5
SHDN
Shutdown Not. Tie this pin to V
BATT
for normal operation. Tie this pin
to ground to disable all circuitry inside the chip. In shutdown the
output voltage will float down to a diode drop below the battery
potential.
6
FB
External Feedback pin. Connect this pin to GND for fixed +3.3V
operation. Connect this pin to a resistor voltage divider between V
OUT
and GND for adjustable output operation.
7
GND
Ground pin for the internal regulator bias currents.
8
P
GND
Switch ground pin. The inductor charging current flows out of this pin.
9
LX
Inductor switching node. Connect one terminal of the inductor to the
positive terminal of the battery. Connect the second terminal of the
inductor to this pin. The inductor charging current flows into LX,
through the internal charging N-channel FET, and out the GND pin.
10
V
OUT
Output Voltage pin. The inductor current flows out of this pin during
the off-time. It is also the internal regulator voltage supply, and
minimum off-time one shot input. Kelvin connect this pin to the
positive terminal of the output capacitor.
4
Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
THEORY OF OPERATION
Detailed Desctiption:
The SP6649 is a step-up DC-DC converter that
starts up with input voltages as low as 0.85V
(typically) and operates with input voltages down
to 0.62V. The ultra low quiescent current of
12A provides excellent efficiencies. In addi-
tion to the 0.3 internal MOSFET the SP6649
has an internal synchronous rectifier eliminat-
ing the need for an external diode. An internal
inductive-damping switch significantly reduces
inductive ringing. If the supply voltage drops
below 0.62V the SP6649 goes into under volt-
age lock-out opening up the internal switches.
An externally programmable low battery detec-
tor with open drain output provides the user the
ability to monitor the supply voltage. The induc-
tor peak current is externally programmable to
allow for a range of inductors.
Control Scheme:
A minimum off-time, current limited pulse fre-
quency modulation (PFM) control scheme com-
bines the high output power and efficiency of a
pulse width modulation (PWM) device with the
ultra low quiescent current of the traditional
PFM. At low to moderate output loads the PFM
control provides a higher efficiencies than tradi-
tional PWM converters are capable of deliver-
ing. At these loads the switching frequency is
determined by a minimum off-time (t
OFF
,
MIN
)
and a maximum on-time (t
ON
,
MAX
) where:
t
OFF
K
OFF
/ (V
OUT
- V
BATT
) and
t
ON
K
ON
/ V
BATT
with
K
OFF
= 1.1V
s and
K
ON
= 3.3Vs.
BLOCK DIAGRAM
VBATT
SHDN
VBATT
VO
UVLO
0.61V
0.61V
SDI
IBIAS
VO
SDI
INTERNAL
Vbatt
FB
LBI
Rlim
Ipkset
current
control
current
reference
REF
FB
VO
VOLOW
S
Qn
CHARGE
Q
R
TOFF
charge end
IUC
QKILL
LX
undercurrent
comparator
INTERNAL
SUPPLY
VO
VBATT
Max
Ton
VOUT
QKILL
PMOS
NMOS
LX
current
reference
overcurrent
comparator
SWITCH GROUND
PGND
GND
LBON
INTERNAL
GROUND
LOAD
Ref
Block
Min
Toff
switch
buffer
+
-
c
+
-
c
n
0.61V
SP6649
+
-
c
+
-
c
+
-
c
1.25V
+
-
c
5
Rev:001 Date:11/20/03
SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
At light loads (plot A in Figure 3) the charge
cycle will take t
ON, MAX
s. For a 1V battery this
would be:
t
ON, MAX
= K
ON
/ V
BATT
= 3.3Vs / 1V = 3.3s
The current built up in the coil during the charge
cycle gets fully discharged (discontinuous con-
duction mode, DCM) When the current in the
coil has reached zero the synchronous rectifier
switch is opened and the voltage across the coil
(from V
BATT
to LX) is shorted internally to
eliminate inductive ringing.
With increasing load (plot B in Figure 3) this
inductor damping time becomes shorter (be-
cause the output will drop quicker below its
regulation point due to the heavier load) up to
the point where it becomes zero. If the load
increases further the SP6649 enters continuous
conduction mode (CCM) where there is always
current in the inductor. The charge time is still
t
ON,MAX
as long as the inductor peak current
limit is not reached (plot C in Figure 3). the
inductor peak current limit can be programmed
by trying a resistor R
LIM
from the R
LIM
pin to
ground where:
I
PEAK
= 1400 / R
LIM
with a maximum recommended I
PEAK
of 1.2A
(or a minimum R
LIM
of 1.17K ).
When the peak current limit is reached the
charge time is short-cycled.
In (plot D of Figure 3) the current reaches the
peak current limit during the charge cycle but
full load is still not reached becuse at the end of
the minimum off-time V
OUT
was still not below
its regulation point. Finally in plot E the maxi-
mum load is reached where the discharge time
has shrunk to its minimum allowed value
t
OFF,MIN
.
Inductor Current vs. Load
Ton Max.
Toff Min.
E. Iripple=Toff* (Vo
- Vi)/L
llim
llim
llim
llim
llim
Ton Max.
Ton Max.
Ton Max.
Ton Max.
Toff Min.
Toff Min.
Toff Min.
Toff Min.
D. Toff*= (Vo
- Vi)/L<Iripple<Ton*Vi/L
C. Iripple=Ton*Vi/L
B. Iripple=Ton*Vi/L
A. Iripple=Ton*Vi/L
Figure 3. Inductor Current vs. Load
6
Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
60
65
70
75
80
85
90
95
100
0.1
1.0
10.0
100.0
1000.0
Iload (mA)
Efficiency (%)
Vi=3.0V
Vi=2.6V
Vi=2.0V
Vi=1.3V
Vi=1.0V
3.200
3.220
3.240
3.260
3.280
3.300
3.320
3.340
3.360
3.380
3.400
0
100
200
300
400
500
I
LOAD
(mA)
V
OUT
(V)
Vi=3.0V
Vi=2.6V
Vi=2.0V
Vi=1.3V
Vi=1.0V
0
50
100
150
200
250
300
350
400
1.0
1.5
2.0
2.5
3.0
Vin (V)
Io (mA)
0
20
40
60
80
100
1.0
1.5
2.0
2.5
3.0
Vin (V)
Iin (uA)
Figure 4. Efficiency vs. Load Current
Figure 5. Line/Load Rejection vs. Load Current
Figure 6. No Load Battery Current
Figure 7. Maximum Resistive Load Current in Startup
Figure 8. Output Ripple, V
IN
=2.6V, I
LOAD
=80mA
Figure 9. Output Ripple, V
IN
=2.6V, I
LOAD
=200mA
PERFORMANCE CHARACTERISTICS
3.3V out, refer to the Circuit in Figure 1, T
AMB
=+25C.
7
Rev:001 Date:11/20/03
SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
4.900
4.920
4.940
4.960
4.980
5.000
5.020
5.040
5.060
5.080
5.100
0
100
200
300
400
500
Iload (mA)
V
out (V)
Vi=4.2V
Vi=3.2V
Vi=2.6V
Vi=2.0V
Vi=1.6V
60
65
70
75
80
85
90
95
100
0.1
1.0
10.0
100.0
1000.0
Iload (mA)
Efficiency (%)
Vi=4.2V
Vi=3.2V
Vi=2.6V
Vi=2.0V
Vi=1.6V
0
50
100
150
200
250
300
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Vin (V)
Iin (uA)
0
50
100
150
200
250
300
350
400
450
500
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Vin (V)
Io (mA)
Figure 10. SP6649 5V Efficiency vs. Load Current
Figure 11. SP6649 5V Line/Load Rejection vs. Load
Current
Figure 12. SP6649 5V No Load Battery Current
Figure 13. SP6649 5V Maximum Resistive Load Current
in Startup
Figure 14. SP6649 5V Output Ripple, Vin=2.6V,
Iload=80mA
Figure 15. SP6649 5V Output Ripple, Vin=2.6V,
Iload=200mA
PERFORMANCE CHARACTERISTICS
5V out, refer to the Circuit in Figure 1, T
AMB
=+25C, R1=374K.
8
Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
(ALL DIMENSIONS IN MILLIMETERS)
PACKAGE: 10-PIN MSOP
0.07 - -
L1
L
R1
1
R
1
1
Seating Plane
1
E1
2
E/2
e1
e
E
D
Gauge Plane
L2
D
A2
A
A1
b
- - 1.1
0 - 0.15
Dimensions in (mm)
10-PIN MSOP
JEDEC MO-187
(BA) Variation
0.75 0.85 0.95
0.17 - 0.27
0.08 - 0.23
3.00 BSC
4.90 BSC
3.00 BSC
0.4 0.60 0.80
0.95
- 0.25 -
- 10 -
0.07 - -
0 8
A
A1
A2
b
c
D
E
E1
L
L1
L2
N
R
R1
0 - 15
1
MIN NOM MAX
e1
e
2.00 BSC
0.50 BSC
c
WITH PLATING
BASE METAL
(b)
-
-
Pin #1 indentifier must be indicated within this shaded area (D/2 * E1/2)
9
Rev:001 Date:11/20/03
SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator Copyright 2002 Sipex Corporation
ADVANCED INFORMATION
Corporation
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.
Sipex Corporation
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: sales@sipex.com
ORDERING INFORMATION
Part Number
Operating Temperature Range
Package Type
SP6649EU .................................................. -40C to +85C ........................................................ 10 Pin MSOP
SP6649EU/TR ............................................ -40C to +85C ................................ (Tape & Reel) 10 Pin MSOP
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