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Thundercomm
TurboX D845 System on Module
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5.13 Fuel gauge
The fuel gauge module offers a hardware-based algorithm that is able to accurately estimate the Battery’s
state of charge by using current monitoring and voltage-based techniques. This hybrid approach ensures
both excellent short-term linearity and long-term accuracy. Furthermore, neither full battery charge cycling,
nor zero-current-load conditions, are required to maintain the accuracy.
The fuel gauge measures the battery pack temperature by sensing the voltage across an external thermistor.
Missing battery detection is also incorporated to accurately monitor battery insertion and removal scenarios,
while properly updating the state of charge when a battery is reconnected.
Using precise measurements of battery voltage, current, and temperature, the fuel gauging algorithm
compensates for the variation in battery characteristics across temperature changes and aging effects. This
provides a dependable state of charge estimate throughout the entire life of the battery and across a broad
range of operating conditions.
Function
Min
Type
Max
Units
Expected use
VBATT_CONN_VSENSE_P & VBATT_CONN_VSENSE_M,
RSENSE_EXT_M & RSENSE_EXT_P
ADC resolution
15
bits
Voltage ADC
9
bits
ID ADC
15
bits
Current ADC
ADC clock
conversion
frequency
200
kHz
Table 5.14- 1 Fuel Gauge
5.14 LED Current Driver
Red, green, and blue(RGB) drivers, which operate off a dedicated supply voltage, are available.
Function
Min
Type
Max
Units
Expected use
RGB_LED
Current per channel (I out)
8
mA
Dimming PWM frequency
0.1
18.75
KHZ
Dimming Resolution
6
9
bit
Table 5.15- 1 LED current Driver