Hi everyone,
I'm experiencing abnormal power consumption in STOP2 mode with my custom board featuring the STM32WB5MMGH module.
According to the datasheet, the power consumption in STOP2 mode should be between 2 and 3 µA. However, my board is drawing around 20 µA. After some troubleshooting, I've narrowed down the issue to the LCD module: when I disable it, the power consumption drops to the expected values.
Here's my current LCD module configuration:
/* USER CODE END LCD_Init 1 */
hlcd.Instance = LCD;
hlcd.Init.Prescaler = LCD_PRESCALER_2;
hlcd.Init.Divider = LCD_DIVIDER_27;
hlcd.Init.Duty = LCD_DUTY_1_8;
hlcd.Init.Bias = LCD_BIAS_1_4;
hlcd.Init.VoltageSource = LCD_VOLTAGESOURCE_INTERNAL;
hlcd.Init.Contrast = LCD_CONTRASTLEVEL_3;
hlcd.Init.DeadTime = LCD_DEADTIME_0;
hlcd.Init.PulseOnDuration = LCD_PULSEONDURATION_1;
hlcd.Init.MuxSegment = LCD_MUXSEGMENT_DISABLE;
hlcd.Init.BlinkMode = LCD_BLINKMODE_OFF;
hlcd.Init.BlinkFrequency = LCD_BLINKFREQUENCY_DIV16;
hlcd.Init.HighDrive = LCD_HIGHDRIVE_ENABLE;
if (HAL_LCD_Init(&hlcd) != HAL_OK)
{
Error_Handler();
}
/** Enable the High Driver
*/
__HAL_LCD_HIGHDRIVER_ENABLE(&hlcd);
I came across a note in the datasheet stating:
"When the LCD relies on the internal step-up converter, the VLCD pin should be connected to VSS with a capacitor. Its typical value is 1 μF."
Could this missing connection of the VLCD pin to VSS be the reason for the excessive power consumption? It's not easy for me to access that specific pin on the current board, so I'd appreciate some certainty before considering a PCB revision.
Has anyone encountered similar issues or can offer any insights?
Any advice would be greatly appreciated!
