KB: Use AOUT PIN to monitor internal Analog & Digital signal for characterization and debug

The RSL10 AOUT pad can be used to monitor internal analog and digital signals for debug and characteristic.

This PIN is very useful. We suggest the customer provide a Test Pad (TP) for this pin.

Part A:

The following voltages can be monitored by using the AOUT PIN:

• Bandgap regulated supply voltage
• VDDRF Voltage
• Baseband timer supply voltage
• VDDC Voltage
• VDDA Voltage
• VDDM Voltage
• VDDPA Voltage

Part B:

The following internal digital signals can be monitored by using the AOUT PIN:

• Bandgap ready
• VCC ready
• DC-DC overload / activated
• VDDRF ready
• VDDC ready
• VDDM ready
• VDDA ready
• 32 kHz crystal oscillator clock
• 32 kHz RC oscillator clock

How to monitor:

RSL10 has a register ACS_AOUT_CTRL (Address =0x40001358):
image

By using this control register, you can obtain a lot of useful information on the AOUT and DIO0 pads.

Five bits can be used to select, giving 32 options:

Examples:

  1. Monitor VCC voltage on AOUT PIN:
    ACS->AOUT_CTRL = AOUT_VCC_SENSE;
    or
    ACS->AOUT_CTRL = 0x01;

  2. Monitor for DCDC overload:
    ACS->AOUT_CTRL = AOUT_DCDC_OVERLOAD;
    or
    ACS->AOUT_CTRL = 0x16;

Below is the RSL10 QFN EVB schematic. You can use test equipment (such as a scope) to monitor at the Test Pad (TP)

NOTE:

You can also use internal ADC to measure the voltage at the AOUT PIN we select to monitor the voltage, such as VCC/ VDDRF etc.

This method can be used to perform voltage trim and calibration for different purposes.

Example:

Select AOUT for ADC input:

Sys_ADC_InputSelectConfig(ADC_CHANNEL, ADC_POS_INPUT_AOUT | ADC_NEG_INPUT_GND);