9
dc2048af
DEMO MANUAL DC2048A
connection to a Dust mote (Dc9003a-B)
Figure 10. LTC3330 Circuit with a Supercapacitor, a Battery Installed
and a Pulsed Load Applied (V
OUT
= 3.6V)
Figure 11. Charging a Supercapacitor with a Battery Installed and a
Pulsed Load (V
OUT
= 3.6V)
Figure 10 shows the LTC3330 with a supercapacitor on
the output, a battery installed and the output voltage set
to 3.6V. The scope shots in Figure 11 were taken after
applying a pulsed load of 15mA for 10ms. With the battery
attached and a pulsed load applied, the EH_ON signal will
switch back and forth from high to low every time the
V
IN
voltage transitions from the VIN_UVLO_RISING to
VIN_UVLO_FALLING threshold. When the pulsed load is
applied, the output capacitor is depleted slightly and the
input capacitor must recharge the output cap. Because the
input capacitance is much less than the output capacitance,
the input capacitor will go through many UVLO transitions to
charge the output capacitor back up to the sleep threshold.
Once the output is charged to the output sleep threshold,
the EH_ON signal will again be consistently high indicating
that the energy harvesting source is powering the output.
PIEZO
MIDE V25W
1µF
6V
4.7µF, 6V
GND
LTC3330
DC2048A F10
AC1
V
IN
CAP
V
IN2
BAT
IPK2
IPK1
IPK0
UV3
UV2
UV1
UV0
OUT2
AC2
SW
SWA
22µH
22µH
SWB
V
OUT
SCAP
BAL
OUT1
OUT0
EH_ON
PGVOUT
V
IN3
22µF
25V
22µF
6V
PRIMARY
CELL
3.2V
+
1µF
6V
180mF
2.5V
180mF
2.5V
HZ202F
100µF
10V
PULSED
15mA
10ms
1s/DIV
DC2048A F11
EH_ON
5V/DIV
V
OUT
50mV/DIV
V
IN
2V/DIV
LOAD CURRENT
20mA/DIV
