Adc Interface - Quectel BC66 Manual

NOTES
1. The level conversion circuit solution shown above is not suitable for applications with high baud rates
exceeding 460 kbps.
" " represents the test points of UART interfaces. It is recommended to reserve the test points of
2.
VBAT_BB, VBAT_RF and PWRKEY for BC66, and the test points of VBAT, BOOT and RESET_N for
BC660K-GL, for convenient firmware upgrade and debugging when necessary.
3. While using BC66, mount R1 in
4. While using BC660K-GL, do not pull up MAIN_RXD to
and substitute D1 in
5. While using BC660K-GL, do not mount R2 in green.
6. For BC660K-GL, pay attention to the following notes about VIO_SEL:
When VIO_SEL is grounded and VBAT ˂ 3.3 V, VDD_EXT = VBAT;
When VIO_SEL is grounded and VBAT ≥ 3.3 V, VDD_EXT = 3.3 V;
When VIO_SEL is floating, VDD_EXT = 1.8 V.

4.9. ADC Interface

BC66 modules provide a 10-bit ADC input channel to read the voltage value of ADC0, while BC660K-GL
provides a 12-bit ADC input channel of the same use.
⚫
The maximum voltage value applicable to BC66's ADC0 is 1.4 V.
⚫
The maximum voltage value applicable to BC660K-GL's ADC0 is 1.2 V.
Table 9: ADC Interface Information
Module Pin Name
BC66 ADC0
BC660K-GL ADC0
NOTE
For BC660K-GL, a 320 kΩ pull-down resistor is integrated inside its BB chip, to which the ADC pin is
connected. This resistor needs to be considered when you apply the voltage division rule (voltage
divider) to relevant calculations.
BC66&BC660K-GL_Compatible_Design
blue and do not mount R2 in green.
red with a 1 kΩ resistor.
Pin No.
9
9
BC66&BC660K-GL Compatible Design
VDD_EXT directly, do not mount
Description
General-purpose ADC interface
General-purpose ADC interface
NB-IoT Module Series
R1 in blue,
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