iCE40 UltraPlus Mobile Development Platform
Evaluation Board User Guide
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All other brand or product names are trademarks or registered trademarks of their respective holders. The specifications and information herein are subject to change without notice.
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FPGA-EB-02007-1.1
3.
Power and Battery
3.1.
Power Source
The MDP board can be powered by three sources:
External
USB Connector J5 (5 V). Green LED D8 and Yellow LED D5 lights up when power is supplied.
External
AP Header Connector J16-8 (5 V) and J16-9 (GND). Yellow LED D5 lights up when power is supplied.
Internal
250 mAH Li-ion battery contained internal to the MDP case.
External power from USB connector J5 and AP header connector J16 are 'Diode-ORd'. If power is supplied to both
connectors, the higher voltage powers the board. When external power is not supplied, the internal Li-ion battery
contained in the case powers the board.
Power switch SW2 turns the board ON and OFF by enabling/disabling the main voltage regulator outputs of 3.3 V, 2.5 V, and
1.2 V. Green LED D9 lights up when the 3.3 V rail is active and indicates that the board is powered ON.
USB
J16
CONN
Li-ion
BATT
BQ24232
VSUPPLY 4.2 V
POWER
SWITCH
VREG 3.3 V
VREG 2.5 V
VREG
1.2 V & 1.8 V
VREG
1.5 V & 2.8 V
VREG
1.8 V & 3.0 V
FLASH, BLE,
GYRO, FGDI
VREG LED
BACKLIGHT
FPGAs VPP2V5
FPGAs VCC
FPGAs VCCIO
CAMERA SENSOR
OVM7692
DISPLAY
DIODES
3.3 V
2.5 V
1.2 V
1.8 V
1.5 V
2.8 V
1.8 V
3.0 V
Figure 3.1.
Power Block Diagram
3.2.
Current Measurement Test Points
Each of the four FPGAs have six 1 Ω resistors in series with their power inputs to allow easy current measurements
using a voltmeter and to ease reworking VCCIO voltage rails. See
Appendix A. iCE40 UltraPlus Mobile Development
Board Schematics
for details.
3.3.
Battery Management and 4.2 V Regulator
Chip BQ24232 U15 provides automatic battery management and the board's 4.2 V regulated voltage rail. The 4.2 V
rail (VSUPPLY) is used to generate all of the board's other voltages. The management chip is always ON (not
controlled by power switch SW2).
When external power is not available, the management chip uses the 250 mAH Li-ion battery internal to MDP case to
generate the 4.2 V rail.
When external 5 V is supplied (4.6 V to 6.0 V), the battery is automatically charged as required. The Green LED D6
lights during charging and turns OFF when charging is complete. Additionally, external power is used to generate the
4.2 V rail. The BQ24232 battery charging is configured with external resistors.
Default resistor configuration:
500 mA input current limit
200 mA charging current
25 mA end of charging termination current threshold
5-hour fast charge time and 30-minute pre-charge
