P2110CSR-EVB
P2110 Powerharvester®Chipset Reference Design
Evaluation Board
DETAILED COMPONENT DESCRIPTIONS AND OPERATING INSTRUCTIONS
Selecting Storage Capacitor
JP1 is used to select the storage capacitor used in the system. C6 is a 1000uF electrolytic
capacitor. C7 is left unpopulated, but is a universal footprint so that a user can add a different
capacitor to the system. C8 is a 50mF super capacitor with low ESR.
Selecting/Setting Output Voltage
S1 is used to select between three output voltage options for VOUT. Selecting DEFAULT sets
VOUT to 3.3V. Selecting 4.1V or 4.2V changes VOUT to the labeled voltage. The DEFAULT
setting can also be adjusted to any voltage between 2.0V and 5.5V simply by changing the
resistors R13 and R14. Refer to the P2110CSR datasheet for information about adjusting
VOUT. Note: Modifying R13 or R14 will also change the set point voltage of S1.
Selecting DSET
S2 is used to select how DSET and DOUT function on the board. Selecting OFF will allow the
P2110CSR to operate normally. If it is desired to monitor DOUT, selecting VOUT will tie DSET
to VOUT through a resistor, R16. In this mode, when VOUT is on, DSET will be pulled high and
DOUT can be used to measure RSSI or to retrieve data from the RF field. Selecting DSET EXT
will allow DSET to be controlled externally using the DSET EXT test point.
LED, Prototyping, and Measuring Current
S3 is used to control flow of current from VOUT. Selecting LED will tie VOUT to the on-board LED, D3,
to be a visual indicator that the system working. Selecting VCC will tie VOUT to the prototype area and
output switch. NOTE: VOUT is routed to the header P1 in parallel with S3, so VOUT is present on the
header pins regardless of S3 position. If using the P1 header, S3 should be in the MEAS position, as
the other positions could use more power, resulting in longer charging periods on the storage cap.
Selecting MEAS allows for current to be measure by connected a current probe between test
points VOUT and LED or VOUT and VCC. Current should be measured using an oscilloscope, as
the time period VOUT is on is generally too short to be seen on a multi-meter.
Output Switch and Batteries
With S3 in the VCC position, the output switch is activated. The output switch includes C9, Q5,
Q6, R17 and R18, and is necessary when using the P2110CSR to charge a battery. The
switch limits the current draw on the battery from the P2110CSR to 10-20nA. This ensures the
P2110CSR does not discharge the battery during periods of non-harvesting.
BT1 is a connection point used for charging a high impedance battery (cell resistance >25
ohms) such as thin-film batteries from Infinite Power Solutions or Cymbet. The cell
impedance of these types of batteries will limit the current drawn from the P2110CSR.
BT2 is a connection point used for charging a low impedance battery such as Li-ion or
Alkaline rechargeable. Resistor R19 is in series with this connection to limit current flow
between the output switch and the battery.
P2110CSR-EVB v1.2 –2015/06
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