®
SP6641A/6641B
500mA Alkaline DC/DC Boost Regulator in SOT-23
■
Ultra Low Quiescent Current: 10µA
■
Wide Input Voltage Range: 0.9V to 4.5V
■
90mA I
OUT
at 1.3V Input (SP6641A-3.3V)
■
500mA I
OUT
at 2.6V Input (SP6641B-3.3V)
■
100mA I
OUT
at 2.0V Input (SP6641A-5.0V)
■
500mA I
OUT
at 3.3V Input (SP6641B-5.0V)
■
Fixed 3.3V or 5.0V Output Voltage
■
Up to 87% Efficiency
■
0.3Ω NFET R
DS
on
■
Startup Voltage Guaranteed at 0.9V
■
0.33A Inductor Current Limit (SP6641A)
■
1A Inductor Current Limit (SP6641B)
■
Logic Shutdown Control
■
SOT-23-5 Package
LX 1
5 V
BATT
SP6641
GND 2
5 Pin SOT-23
V
OUT
3
4 SHDN
APPLICATIONS
■
PDA's
■
DSC's
■
CD/MP3 Players
■
Pagers
■
Digital Cameras
■
Portable Handheld Medical Devices
Now Available in Lead Free Packaging
DESCRIPTION
The SP6641 is an ultra-low quiescent current, high efficiency, DC-DC boost converter designed
for single and dual cell alkaline, or Li-ion battery applications found in PDA’s, MP3 players, and
other handheld portable devices. The SP6641 features a 10µA quiescent current, a 0.3Ω N-
channel charging switch, 0.9V input startup, and a 0.33A or 1.0A inductor current limiting feature.
The SP6641 is offered in a 5 pin SOT-23 package and provides an extremely small power supply
footprint optimized for portable applications. The SP6641 is preset to 3.3V and can be controlled
by a 1nA active LOW shutdown pin.
L1
0.9V to 4.5V
V
BATT
V
BATT
5
®
1 LX
D1
2 GND
3 V
OUT
R1
C3
C1
U1
SP6641A
SHDN
SHDN
I
OUT
(mA)
4
C2
V
OUT
+3.3V or 5V
SP6641A 3.3V & 5V:
C1 = C2 = 22µF Ceramic, L1 = 22µH CDRH5D28,
D1 = MBR0520, C3 = Open, R1 = Shorted.
SP6641B 3.3V & 5V:
C1 = C2 = 100µF POSCAP, L1 = 10µH CDRH5D28,
D1 = ZHCS2000, C3 = 1µF Ceramic, R1 = 10Ω.
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
1.0
SP6641B, 1.0A, 3.3V
SP6641B, 1.0A, 5V
SP6641A, 0.33A, 3.3V
SP6641A, 0.33A, 5V
1.5
2.0
2.5
3.0
3.5
4.0
4.5
V
IN
(V)
Figure 1. Typical Application Schematic
Rev. 5/26/05,
*Patent Pending
Figure 2. Maximum Load Current in Operation
© Copyright 2002 Sipex Corporation
SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23
1
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, V
OUT
, SHDN, V
BATT
to GND pin ....... -0.3 to 6.0V
LX Current .......................................................... 1.5A
Reverse V
BATT
Current ................................... 220mA
Storage Temperature ........................ -65°C to 150°C
Operating Temperature ..................... -40°C to +85°C
Lead Temperature (Soldering, 10 sec) .......... 300
°C
ELECTRICAL SPECIFICATIONS
V
BATT
= V
SHDN
= 1.3V, I
LOAD
= 0mA, -40°C <T
A
< +85°C, V
OUT
= +3.3V or +5.0V preset, typical values at 27°C
unless otherwise noted.
PARAMETER
Input Voltage Operating Range,
V
BATT
Startup Voltage, V
BATT
Output Voltage, V
OUT
Quiescent Current into V
OUT
,
I
Q(OUT)
Quiescent Current into V
BATT
,
I
QB
Shutdown Current into V
OUT
,
I
SHDN
Shutdown Current into V
BATT
,
I
SHDN
Inductor Current Limit
(SP6641A)
Inductor Current Limit
(SP6641B)
Output Current (SP6641AEK-3.3)
Output Current (SP6641BEK-3.3)
Output Current (SP6641AEK-5.0)
Output Current (SP6641BEK-5.0)
Minimum Off-Time Constant
K
OFF
NMOS Switch Resistance
SHDN Input Voltage
Vil
Vih
SHDN Input Current
MIN
0.5
0.85
3.16
4.80
3.30
5.00
10
250
1
20
280
850
330
1000
90
190
200
500
100
175
275
500
1.50
0.3
80
1
100
0.75
20
TYP
MAX
4.5
0.90
1.00
3.44
5.20
15
500
500
100
380
1150
UNITS
V
V
V
V
V
µA
nA
nA
nA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
V*µs
Ω
%
%
nA
V
BATT
=1.3V
V
BATT
=2.6V
V
BATT
=1.3V
V
BATT
=2.6V
V
BATT
=2.0V
V
BATT
=3.3V
V
BATT
=2.0V
V
BATT
=3.3V
T
OFF
≥
K
OFF
/ (V
OUT
– V
IN
)
Inmos=100mA
% of V
BATT
% of V
BATT
CONDITIONS
after startup
R
LOAD
=3kΩ, T
A
=27°C
R
LOAD
=3kΩ,-40°C <T
A
< +85°C
3.3V V
OUT
preset
5.0V V
OUT
preset
V
OUT
=3.5V, 3.3V V
OUT
preset
V
OUT
=5.5V, 5.0V V
OUT
preset
V
OUT
=3.5V, 3.3V V
OUT
preset
V
OUT
=5.5V, 5.0V V
OUT
preset
V
SHDN
=0V
V
SHDN
=0V
Rev. 5/26/05,
*Patent Pending
SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23
© Copyright 2002 Sipex Corporation
2
PIN DESCRIPTION
PIN NO.
1
PIN NAME
LX
DESCRIPTION
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 through the GND
pin.
Ground pin. The internal regulator bias currents and the inductor
charging current flows out of this pin.
Output voltage sense pin, internal regulator voltage supply, and
minimum off-time one shot input. Kelvin connect this pin to the positive
terminal of the output capacitor, but for SP6641B, use 10Ω series
resistor and 1µF bypass per Figure 1 schematic.
Shutdown. Tie this pin to V
BATT
for normal operation. Tie this pin the
ground to disable all circuitry inside the chip. In shutdown mode, the
output voltage will float at a diode drop below the battery potential.
Battery voltage pin. The startup circuitry runs off of this pin. The
regulating circuitry also uses this voltage to control the minimum off-
time. T
OFF
≥
K
OFF
/ (V
OUT
– V
IN
).
2
3
GND
V
OUT
4
SHDN
5
V
BATT
BLOCK DIAGRAM
V
BATT
V
OUT
V
BATT
LX
Internal
V
BATT
V
BATT
V
OUT
LOAD
SU
EN OSC
V
OUT
V
BATT
R
T
OFF
Q
CHARGE
NGATE
M
V
OUT
1
DRIVER
LX
+
SUGATE
I
PK
/M
ITH
C
-
ICHN
SHDN
SHDN
Min.
T
OFF
V
OUT
GND
REFREADY
SHDN
Ref
Block
Internal
Ground
+
REF
FB
C
-
V
OUT(LOW)
Qn
S
V
OUT
SP6641
Internal
Supply
Rev. 5/26/05,
*Patent Pending
SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23
© Copyright 2002 Sipex Corporation
3
PERFORMANCE CHARACTERISTICS
Refer to the circuit in Figure 1, T
AMB
= +25°C
100
95
90
V
IN
= 3.0V
V
IN
= 2.6V
V
IN
= 2.0V
V
IN
= 1.3V
V
IN
= 1.0V
100
95
90
V
IN
= 3.0V
V
IN
= 2.6V
V
IN
= 2.0V
V
IN
= 1.3V
V
IN
= 1.0V
Efficiency (%)
0.1
1.0
10.0
100.0
1000.0
Efficiency (%)
85
80
75
70
65
60
85
80
75
70
65
60
0.1
1.0
10.0
100.0
1000.0
Iload (mA)
Iload (mA)
Figure 3. SP6641AEK - 3.3 Efficiency vs Load Current
Figure 4. SP6641BEK - 3.3 Efficiency vs Load Current
3.400
3.380
3.360
3.340
3.320
V
IN
= 3.0V
V
IN
= 2.6V
V
IN
= 2.0V
V
IN
= 1.3V
V
IN
= 1.0V
3.400
3.380
3.360
3.340
3.320
V
OUT
V
OUT
3.300
3.280
3.260
3.240
3.220
3.200
0
50
100
150
Iload (mA)
200
250
3.300
3.280
3.260
3.240
3.220
3.200
0
200
400
Iload (mA)
600
800
V
IN
= 3.0V
V
IN
= 2.6V
V
IN
= 2.0V
V
IN
= 1.3V
V
IN
= 1.0V
Figure 5. SP6641AEK - 3.3 Line/Load Rejection vs Load
Current
Figure 6. SP6641BEK - 3.3 Line/Load Rejection vs Load
Current
100
95
90
100
95
90
Efficiency (%)
Vi=4.2V
Vi=3.6V
Vi=3.3V
Vi=2.0V
Vi=1.3V
Efficiency (%)
85
80
75
70
65
60
0.1
Vi=4.2V
Vi=3.6V
Vi=3.3V
Vi=2.0V
Vi=1.3V
85
80
75
70
65
60
0.1
1.0
10.0
Iload (mA)
100.0
1000.0
1.0
10.0
Iload (mA)
100.0
1000.0
Figure 7. SP6641AEK-5.0 Efficiency Vs Load Current
Figure 8. SP6641BEK-5.0 Efficiency Vs Load Current
Rev. 5/26/05,
*Patent Pending
SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23
© Copyright 2002 Sipex Corporation
4
PERFORMANCE CHARACTERISTICS
Refer to the circuit in Figure 1, T
AMB
= +25°C
5.200
5.180
5.160
5.140
Vi=4.2V
Vi=3.6V
Vi=3.3V
Vi=2.0V
Vi=1.3V
Vo (V)
5.100
5.080
5.060
5.040
5.020
5.000
4.980
4.960
4.940
4.920
Vi=4.2V
Vi=3.6V
Vi=3.3V
Vi=2.0V
Vi=1.3V
200
400
Iload (mA)
600
800
Vo (V)
5.120
5.100
5.080
5.060
5.040
5.020
5.000
0
50
100
150
Iload (mA)
200
250
4.900
0
Figure 9. SP6641AEK-5.0 Line/Load Rejection Vs Load
Current
Figure 10. SP6641BEK-5.0 Line/Load Rejection Vs
Load Current
250
SP6641AEK-5.0
SP6641AEK-3.3
Iin (uA)
Iin (uA)
500
450
SP6641B-5.0
SP6641B-3.3
200
400
350
300
250
200
150
150
100
50
100
50
0
0.5
1.0
1.5
2.0
2.5
Vin (V)
3.0
3.5
4.0
4.5
0
0.5
1.0
1.5
2.0
2.5
Vin (V)
3.0
3.5
4.0
4.5
Figure 11. SP6641AEK-3.3 & SP6641AEK-5.0 No Load
Battery Current
Figure 12. SP6641BEK-3.3 & SP6641AEK-5.0 No Load
Battery Current
250
700
600
500
200
Io (mA)
Io (mA)
SP6641AEK-3.3, 22µH
SP6641AEK-3.3, 10µH
150
400
300
200
100
0
0.5
SP6641BEK-3.3, 22µH
SP6641BEK-3.3, 10µH
SP6641BEK-5.0, 22µH
SP6641BEK-5.0, 10µH
100
50
SP6641AEK-5.0, 22µH
SP6641AEK-5.0, 10µH
0
0.5
1.0
1.5
2.0
2.5
Vin (V)
3.0
3.5
4.0
4.5
1.0
1.5
2.0
2.5
Vin (V)
3.0
3.5
4.0
4.5
Figure 13. SP6641AEK-3.3 & SP6641AEK-5.0
Maximum Resistive Load Current in Startup
Rev. 5/26/05,
*Patent Pending
Figure 14. SP6641BEK-3.3 & SP6641BEK-5.0
Maximum Resistive Load Current in Startup
© Copyright 2002 Sipex Corporation
SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23
5
