STC12C5A60 MCU has large working current

xiang1yuan

STC12C5A60 MCU has large working current [Copy link]

The manual of the STC12C5A60 microcontroller provides an operating current of 2~7mA. However, when only a crystal oscillator (and two 22pF capacitors), a 10K reset resistor, and a 5V power supply are connected and a simple ADC and IO control program is run, the actual measured current is much higher, as follows:

At 4MHz, the operating current is more than 10mA;

At 11.0592MHz, the operating current is more than 15mA;

At 18.432MHz, the operating current is more than 20mA;

Have you ever encountered this situation?

lishiwen

The P2 port is an 8-bit bidirectional I/O port with an internal pull-up resistor. The P2 port buffer can receive and output 4 TTL gate currents. When the P2 port is written "1", its pin potential is pulled high by the internal pull-up resistor and used as input. When used as input, the pin potential of the P2 port is pulled low externally and outputs current, which is due to the internal pull-up.

wangerxian

Are you measuring the current of the entire board or the microcontroller?

zwp_kevin

Please tell me the details of how to test and check whether the test method is correct.

macadam

An IO driver may increase the current by several mA. Is it possible to optimize this aspect?

dabiaoke

Is it easy to test the power supply current at the mA level? Is it related to the measurement tool, or is it that the direct reading of the DC source is generally not accurate enough? Can I use the mA range of the multimeter?

茗焜

No picture, no truth, no analysis

damiaa

Poor peripheral circuit processing is also one of the reasons for the increase in current.