Datasheet

QuickLogic EOS S3 Ultra Low Power multicore MCU datasheet - Version 3.3d 27-129
© 2020 QuickLogic Corporation www.quicklogic.com 89
9.3.2. Functional Description
In brief, the ADC voltage measurement core includes an input multiplexer, a delta-sigma modulator, and a digital control
core. The digital control core controls the analog blocks power up/down sequences, generates the delta-sigma control
signals and implements the output decimation.
9.3.3. Electrical Characteristics
The following table lists the key electrical characteristics for the ADC module.
A
GND
= 0 V DC, F
CLK
= 500 kHz, T
J
= –25 C to +125 C, unless otherwise specified.
Table 30: ADC Electrical Characteristics
Symbol Description Min. Typ. Max. Units
V
AVDD
Analog Supply Voltage 1.62 1.80 3.63 V
V
DAC
Input Voltage Conversion Range 0 - 1.4 V
F
CLK
Delta-Sigma Clock Frequency 200 1000 2000 kHz
Temp
Temperature Range -20 - 85 °C
I
AVDD
Analog Current 0.1 0.2 0.3 mA
IQ
PD
Total Power Down Current Consumption - - 1 µA
ADC
ADC Resolution Voltage Per Step - 0.34 - µV
T
CONV
ADC Conversion Time
a
2.5 12.5 25 ms
a. ADC conversion time is ~5,000 F
CLK
cycles.
9.3.4. PCB Layout Recommendations
When using ADC, the following PCB layout recommendations include:
• Minimize the distances between the ADC input and the location where the voltage is being measured. Avoid
routing where it is close to noise sources such as clock generators, DC/DC converters and, data/address buses.
• Minimize inductance and reduce series resistance by using wide tracks. Use grounded guard traces when
possible. A trace with a 10-mil minimum width and spacing is recommended.
9.3.5. Example Application
The ADC input voltage conversion range is 0 V to 1.4 V. Most rechargeable battery outputs are higher than the ADC input
voltage. To support higher input voltage range, a maximum of up to 4 VDC, use an external analog level shifter to scale the
battery voltage to ensure it is compatible with the ADC voltage range.
The following figure shows an example.