DA9011.001
28 Jan 2004
MAS9011
This is preliminary information on a new
product under development. Micro Analog
Systems Oy reserves the right to make any
changes without notice.
Solar Cell System Manager
•
Power On Indicator
•
Low Battery Indicator
•
Battery Overcharging
Protection
DESCRIPTION
The solar cell system manager is an analog circuit,
which monitors the supply voltage of a battery-
powered system containing solar cells. The solar
manager uses three output signals to indicate the
state of the system. Power On (PO) indicates
whether the supply voltage is high enough to run
the system. Low Battery (LB) is used to signal the
situation where the battery is low. The third signal,
SOL, is used for battery charging control. It
indicates when the battery is full and the charging
process should be stopped.
FEATURES
•
•
•
Power On Indicator
Low Battery Indicator
Battery Overcharging Protection
APPLICATIONS
•
Solar Cell Powered Watch
BLOCK DIAGRAM
VDD
PO
LB
MAS9011
SOL
GND
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DA9011.001
28 Jan 2004
PAD LAYOUT
670
µm
GND
VDD
SOL
MAS
9011
PO
LB
DIE size = 0.67 mm x 1.43 mm
PAD size = 80 x 80
µm
Note:
Make sure that VDD is the first pad to be bonded. Pick-and-place and all component assembly are
recommended to be performed in ESD protected area.
Note:
If the die is to be placed on metal plane, the metal plane should be connected to VDD or left floating. This
because the substrate of the die is internally connected to VDD.
Note:
Coordinates are pad center points where origin has been located in bottom-left corner of the silicon die.
Pad Identification
Power Supply Ground
Power Supply Voltage
Full Battery Output
Power On Output
Low Battery Output
Name
GND
VDD
SOL
PO
LB
X-coordinate
174
µm
334
µm
495
µm
211
µm
462
µm
Y-coordinate
1208
µm
1210
µm
1221
µm
221
µm
221
µm
1434
µm
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DA9011.001
28 Jan 2004
FUNCTIONAL DESCRIPTION
The solar manager generates three signals: PO
(Power On), LB (Low Battery) and SOL (Full
Battery).
These signals are produced by three comparators
which have hysteresis build in. Each comparator
compares supply voltage (VDD) to
internal
switching levels (see Electrical Characteristics on
next page). The current consumption of the
comparators is very low. The electrical parameters
are described more detailed in the Electrical
Characteristics chapter.
PO signal can be used to stop the whole system
whenever the power supply level has dropped low
enough. When power supply voltage is too low, the
PO goes high to give signal to watch
microcontroller to go power down.
LB signal indicates that the battery is low but not
empty. LB goes high when power supply level is too
low.
SOL is used for battery charging control of the solar
watch. When power supply voltage goes high
enough, the internal PMOS switch between VDD
and SOL pins is switched on to shunt the solar cell
charging current and to prevent battery
overcharging.
In operation without an external Schottky diode
between the pins SOL and GND, the voltage at pin
SOL is clamped to about 700 mV below GND by a
diode-connected PNP transistor.
MAS9011 does not have any control pin. After the
power supply is connected the device is ready to be
used.
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28 Jan 2004
ABSOLUTE MAXIMUM RATINGS
All voltages with respect to ground.
Parameter
Supply Voltage
Voltage range for all pins
Operating temperature
Storage Temperature
Symbol
VDD
T
A
T
S
Conditions
Min
-0.3
-0.3
-40
-50
Max
6.0
VDD+0.3
+85
+125
Unit
V
V
o
C
o
C
ELECTRICAL CHARACTERISTICS
T
A
= -40°C to +85°C, typical values at T
A
= +27°C, unless otherwise specified.
Parameter
Supply voltage
Current consumption
PO switching level
PO hysteresis
PO output voltage
LB switching level
LB hysteresis
LB output voltage
SOL switching level
SOL hysteresis
SOL output current
SOL leakage current
LB on level – PO off level
Symbol
VDD
I
Q
V
PO
V
PO(H)
V
PO(OUT)
V
LB
V
LB(H)
V
LB(OUT)
V
SOL
V
SOL(H)
I
SOL
Conditions
Min
1.00
Typ
100
Max
3.00
300
Unit
V
nA
V
mV
Switching On
Switching Off
VDD = 1.05 V,
I
PO
= -1.0 mA
Switching On
Switching Off
VDD = 1.15 V, I
LB
= 50 µA
VDD = 1.30 V, I
LB
= -50 µA
Switching On
Switching Off
VDD = 1.4 V, V
SOL
= 0 V
VDD = 1.7 V
-50
0.95
1.15
1.10
50
0.06
1.19
1.22
30
0.20
1.55
1.48
70
TBD
+50
90
V
V
mV
V
V
mV
nA
nA
mV
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DA9011.001
28 Jan 2004
TYPICAL APPLICATION
4.7 µF
Solar cells
VDD
PO
LB
Watch
MCU
Display /
Stepper
Motors
1.5 V
+
–
MAS9011
SOL
GND
Figure 1.
Typical application circuit of MAS9011
5 (9)
