ALD8100XX Datasheet, PDF (1/17 Pages) Advanced Linear Devices – SUPERCAPACITOR AUTO BALANCING (SAB) MOSFET ARRAYS

ADVANCED
LINEAR
DEVICES, INC.
ALD8100XX/ALD9100XX FAMILY of SUPERCAPACITOR
AUTO BALANCING (SAB^™) MOSFET ARRAYS
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GENERAL DESCRIPTION
The ALD8100xx/ALD9100xx family of Supercapacitor Auto Balanc-
ing MOSFET Arrays, or SAB™ MOSFETs, are designed to address
voltage and leakage current balancing of supercapacitors connected
in series. Supercapacitors, also known as ultracapacitors or
supercaps, connected in series can be balanced with single or
multiple ALD8100xx/ALD9100xx packages. These SAB MOSFETs
are built with ALD production proven EPAD^® MOSFET technology.
SAB MOSFETs have unique electrical characteristics for superior
active continuous leakage current regulation and self-balancing of
stacked series-connected supercapacitors while dissipating near
zero leakage currents, practically eliminating extra power consump-
tion. For many applications, SAB MOSFET automatic charge bal-
ancing offers a simple, economical and effective method to bal-
ance and regulate supercapacitor voltages. With SAB MOSFETs,
each supercapacitor in a series-connected stack is continuously
monitored and automatically controlled for precise, effective bal-
ancing of its voltage and leakage current.
The SAB MOSFET regulates the voltage across a supercapacitor
cell by increasing its drain current exponentially across the
supercapacitor when its voltage increases, and by decreasing its
drain current exponentially across the supercapacitor when its volt-
age decreases. When a supercapacitor cell is charged to a volt-
age less than 90% of the desired voltage limit, the SAB MOSFET
across the supercap is turned off and there is zero leakage current
contribution from the SAB MOSFET. On the other hand, when the
voltage across the supercapacitor is over the desired voltage limit,
the SAB MOSFET is turned on to increase its drain currents to
keep the supercapacitor voltage from rising. Simultaneously, the
voltages and leakages of other supercapacitors in the series stack
are lowered to result in a near zero net increase in leakage current.
The ALD8100xx/ALD9100xx SAB MOSFET family offers a selec-
tion of different threshold devices for various supercapacitor maxi-
mum operating voltage values and desired leakage balancing char-
acteristics as well as different temperature range environments. A
list of the available ALD part numbers can be found in the tables on
pages 6 and 7 of this document. For individual datasheets and
specifications, please visit www.aldinc.com under “SAB MOSFET”.
SAB MOSFET ADVANTAGES
The ALD8100xx/ALD9100xx family of SAB MOSFETs are designed
for automatic supercapacitor balancing. They are replacements for
many other passive or active supercapacitor balancing methods
where cost, board space, efficiency, simplicity and power dissipa-
tion are important design considerations. For example, in applica-
tions where supercapacitors require minimum long-term power dis-
sipation (internal leakage currents) as a primary goal, ALD8100xx/
ALD9100xx SAB MOSFETs are simpler and more effective in per-
forming the leakage balancing function, using significantly less
board space and contributing no additional charge loss beyond the
supercapacitor’s own leakages. Other common methods of charge
PIN CONFIGURATIONS
ALD8100xx
IC* 1
M1
D_{N1 2}
G_N1 3
S_{N1 4} ^V-
V- 5
D_{N4 6}
M4
G_{N4 7}
S_{N4 8} ^V-
16 IC*
M2
15 DN2
14 G_N2
V- _{13 SN2}
12 V+
M3 _{11 DN3}
10 ^GN3
V- _{9 SN3}
SUPERCAPACITORS
Supercapacitors are typically rated with a nominal recommended
working voltage established for long life at their maximum rated
operating temperature. When a supercapacitor cell voltage ex-
ceeds its rated voltage for a prolonged time period, it experiences
reduced lifetime and eventual rupture and catastrophic failure. To
prevent such an occurrence, in most applications having two or
more supercapacitors connected in series, a means of automati-
cally monitoring and adjusting charge-balancing at their maximum
operating voltages is required. This is due to different internal leak-
age currents in each specific cell.
The supercapacitor’s leakage current is a variable function of many
parameters such as aging, initial leakage current at zero input volt-
age, material and construction of the supercapactor, its chemistry
composition, its leakage as a function of the charging voltage and
the charging current and temperature, operating temperature range,
and the rate of change of many of these parameters. Supercapacitor
balancing must correct for these changing effects automatically,
with minimal added leakage currents or power consumption.
SCL PACKAGES
ALD9100xx
IC* 1 V-
8 V+
G_N1 2
D_N1 3
S_N1 4
7 G_N2
6 DN2
5 SN2, V-
SAL PACKAGES
*IC pins are internally connected, connect to V-
©2014 Advanced Linear Devices, Inc., Vers. 2.0
www.aldinc.com
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