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dc2042af
DEMO MANUAL DC2042A
APPLICATION INFORMATION
VIN SOLAR (E7):
Input to the LTC3459, solar-powered
circuit with maximum power point control provided by
the LTC2935-4. The input regulation point for the MPPC
function is 1.73V. The input range is 1.72V to 3.3V.
HGND (E9, E13):
This is the header ground. HGND is the
switched ground to the headers that ensures the load is
presented with a quickly rising voltage. BGND and HGND
are connected through Q3 when the VMCU voltage with
respect to BGND reaches the rising RESET threshold of
U2 and disconnected when VMCU falls to the falling reset
threshold. The board is configured from the factory to
connect BGND and HGND when VMCU equals 3.15V and
disconnect them when VMCU equals 2.25V.
VMCU (E10, E12):
Regulated output of all the active en-
ergy harvester power management circuits, referenced to
BGND. When VMCU is referenced to HGND it is a switched
output that is passed through the headers, J1 and J2, to
power the load.
J2 DUST HEADER SIGNALS
Pin 1 (VSUPPLY):
Switched power from EH multisource
demo board. As configured from the factory via the
LTC2935-2 circuitry, this voltage is switched on at 3.15V
and off at 2.25V. On the board this node is labeled VMCU.
Pin 2 (NC):
No connect on EH multisource demo board.
Pin 3 (GND):
Switched GND when VSUPPLY is greater
than 3.15V, rising and 2.25V, falling. On the board this
signal is labeled HGND.
Pin 4 (PGOOD):
PGOOD signal from EH multisource
demo board. When this signal is high, the SPDT switch
on the DUST demo board will switch from the battery to
the energy harvested source.
Pin 5 (KEY):
Metal insert in header to ensure proper in-
sertion location and orientation. No electrical connection.
Pin 6 (VBAT):
Raw battery voltage from (to) DUST board.
Pin 7 (RSVD):
Reserved for future use, no connection on
EH multisource board.
Pin 8 (EHORBAT):
Signal indicating if the battery or the
energy harvester is providing power to the system. Refer
to the individual device data sheet for the interpretation
of the polarity.
Pin 9 (I/O 2):
Connected to general purpose I/O input on
DUST DC9003A-X.
Pin 10 (I/O 1):
Connected to general purpose I/O input on
DUST DC9003A-X.
Pin 11 (+5V):
5V input provided by DC9006A board, not
anticipated to be used by or provided from EH board.
Pin 12 (V+):
12V input provided by DC9006A board, not
anticipated to be used by or provided from eh board.
J3 AND J4 TRANSDUCER HEADER SIGNALS
Pin 1 (VIN_LTC3459):
Solar panel input. The allowable
range for this input voltage is 1.72V to 3.3V.
Pins 2, 4, 6, 8, 10 (GND):
Connected to board ground
“BGND” to power the power management circuits.
Pin 3 (VIN_LTC3105):
Connect in series with 4mA to 20mA
loop. The Loop current will flow into this pin and out a
board GND connection.
Pin 5 (VIN_LTC3108):
Thermal electric generator input,
input to step-up transformer. The allowable range for this
input voltage is 20mV to 400mV. The source impedance of
the TEG should be less than 10Ω for good power matching.
Pin 7 (VIN_LTC3588-1):
Rectified AC voltage, direct input
to LTC3588-1 DC/DC. The allowable range for this input
voltage is 5V to 18V. If the DC source is greater than 18V,
the maximum current allowed into this pin is 5mA.
Pin 9 (PZ1):
Raw battery voltage from (to) the DC9003A-X
DUST board.
Pin 11 (PZ2):
Reserved for future use, no connection on
EH multisource board.
Pin 12 (KEY):
Metal insert in header to ensure proper
insertion location and orientation. No electrical connection.
