Dlp Nirscan Nano Hardware; External Power Supply Requirements - Texas Instruments DLP NIRscan User Manual

4.1

External Power Supply Requirements

The DLP NIRscan Nano is powered from either a battery or a USB cable. The power requirements are:
• USB Cable:
– Voltage: 4.75 to 5.25 V
– Current Maximum: 560 mA when operating and 1 A when charging
– Cable: 3 ft, USB A male to micro-USB B male (cable not included)
– Digi-Key Part Number: Q853-ND
– Manufacturer: Qualtek
– Part Number: 3025010-03
• Battery: (Not Included)
– Single-Cell Lithium-Polymer UL certified battery
• Voltage: 3.7 V
• Capacity: 1700 mA
• Manufacturer: Tenergy
• Part Number: 103450
NOTE: Only connect Tenergy 103450 Lithium Polymer UL certified battery or equivalent UL certified
battery that meets: maximum charge current of 1A or more, maximum charging voltage of
4.23V or higher, battery over voltage protection at 4.305V or higher, and battery under
voltage lockout at 2.5V or less.
If a battery is connected to the NIRscan Nano, a thermistor is required to safely charge the battery and
monitor its temperature. The battery thermistor requirements are:
• Battery Thermistor: (Not Included)
– 10-kΩ NTC thermistor
• Manufacturer: Murata
• Part number: NXRT15XH103FA1B040
• Digi-Key part number: 490-7167-ND
Figure 4-1 shows a block diagram of the power circuits. The main power input is the external battery and
USB connector. The bq24250 includes a single-cell battery charger and a highly efficient DC-DC converter
to regulate the system voltage at 3.52 V. With an optional thermistor, the bq24250 monitors the
temperature of the battery during charging. Note that a thermistor is required to charge the battery. The
battery charger is set to supply up to a 1-A current during charging.
The rest of the devices regulate power to the subsystem as follows:
• The DLPA2005 in the DLP controller board regulates the power to the DLP2010NIR and DLPC150.
• The TPS82671 in the microcontroller board regulates the 1.8-V supply used by the Bluetooth
subsystem CC2564MODN. To conserve power, a TPS22904 load switch turns off the 1.8-V supply to
the Bluetooth subsystem when not in used.
• The TPS630636 in the microcontroller board supplies the main 3.3 V for the microprocessor and
interface inputs and outputs to DLPC150, CC2564MODN, and Tiva microprocessor.
DLPU030B – June 2015 – Revised July 2015
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DLP NIRscan Nano Hardware

Copyright © 2015, Texas Instruments Incorporated
DLPU030B – June 2015 – Revised July 2015
DLP NIRscan Nano Hardware
Chapter 4
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