CBC915 EnerChip Energy Processor
EnerChip(s). Once the maximum peak power point is found, the CBC915 will then set the ISOLATE EN line high
to connect the boost converter to the power management circuits, then repeatedly pulse the CAP CHG pin low.
The periodic pulsing of EN CAP CHG/ pin low enables small amounts of charge energy to be transferred from
the boost converter to the output capacitor with each low pulse on the EN CAP CHG/ pin. While the output
capacitor is being charged, the CBC915 will monitor the output capacitor voltage on the VCAP pin. When the
output capacitor voltage rises to 2V, the CBC915 will stop pulsing and set the EN CAP CHG/ pin low continuously;
this state allows maximum energy to be transferred from the boost converter into the output capacitor. When
the output capacitor voltage reaches 3.4V, the CBC915 will set the EN VOUT/ line low, connecting the output
capacitor to the application system load. At the same time, the CBC915 will pulse the EC CHG/ line low and pulse
the CUTOFF RST line high, thereby connecting the EnerChip to the boost converter, output capacitor, and applying
power to the application system load. The CBC915 then monitors the output of the boost converter; when the
boost converter is in regulation the CBC915 will simultaneously pulse low the EC CHG/, CAP CHG/, and MPPT/
pins. This state indicates the output is turned on and the system is in regulation, which typically happens once
the EnerChips have nearly a full charge.
Status Input Pin
This pin is internally pulled high. Tie this pin to a switch or open drain/collector output to pull low. When pulled low
STATUS SW/ will cause the EC CHG LED/, MPPT LED/, and CAP CHG/ pins to pulse low depending on the state
of the Energy Processor. When in the normal state, with power applied to the system and in regulation with fully
charged EnerChips, all the lines will pulse low simultaneously. If the STATUS SW/ pin is held low for more than 10
seconds while the system is in regulation, EN VOUT/ will go high, shutting off power to the application system.
Subsequent pulses of less than 10 seconds will cause the EN CAP CHG/ and MPPT/ pins to pulse low and the
EN VOUT/ line to remain in the high (power disconnected) state. Holding STATUS SW/ line low for greater than 10
seconds will restore the Energy Processor to its normal state, with EN VOUT/ in the low state, power applied to the
application system, and all three status lines pulsing low in response to a low level pulse on STATUS SW/.
Calibration Function
The CBC915 features a calibration function to remove errors caused by unit to unit variation in the voltage
divider resistors (R1 and R2 of Figure 3) used to drive the ECFB input. The CALIBRATE/ pin has an internal pull
up resistor and can be driven by an open drain/collector output or switch contact. To calibrate apply 4.06V to the
V+ node. Then short the CALIBRATE/ pin to ground for approximately 100mS. The EC CHG LED/, MPPT LED/, and
CAP CHG/ pins will simultaneously pulse low when the CBC915 has stored its calibration values.
Operating Modes
•
•
•
•
Mode 0: Electromagnetic transducers; input voltage range 0.5V to 4V after rectification and filtering.
Mode 1: Thermoelectric generators; input voltage range 400mV for startup. 200mV to 1V at matched
impedance.
Mode 2: Piezoelectric generators; input voltage range 4V to 20V after rectification, loaded to matched
impedance.
Mode 3: Photovoltaic cells; 900mV to 4V at matched impedance.
MODE
0 (Electromagnetic)
1 (Thermoelectric)
2 (Piezoelectric)
3 (Photovoltaic)
MODE SEL3
X
X
X
X
MODE SEL2
X
X
X
X
MODE SEL1
0
0
1
1
MODE SEL0
0
1
0
1
DS-72-15 Rev C
©2010-2011 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com
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