ST72652 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST72652

LOW-POWER, FULL-SPEED USB 8-BIT MCU WITH 32K FLASH, 5K RAM, FLASH CARD I/F, TIMER, PWM, ADC, I2C, SPI

STMicroelectronics 

ST7265x

PWM/BRM GENERATOR (Cont’d)

PWM/BRM Outputs

The PWM/BRM outputs are assigned to dedicated

pins.

The PWM/BRM outputs can be connected to an

RC filter (see Figure 53 for an example).

The RC filter time must be higher than TCPUx64.

Figure 53. Typical PWM Output Filter

OUTPUT

STAGE

OUTPUT

VOLTAGE

Rext

Cext

Table 29. 6-Bit PWM Ripple After Filtering

Cext (µF)

0.128

1.28

12.8

V RIPPLE (mV)

78

7.8

0.78

With RC filter (R=1KΩ),

fCPU = 8 MHz

VDD = 5V

PWM Duty Cycle 50%

R=Rext

Note: after a reset these pins are tied low by de-

fault and are not in a high impedance state.

Figure 54. PWM Simplified Voltage Output After Filtering

V DD

PWMOUT

0V

V DD

OUTPUT

VOLTAGE

Vripple (mV)

VOUTAVG

0V

"CHARGE"

"DISCHARGE"

"CHARGE"

"DISCHARGE"

V DD

PWMOUT

0V

V DD

OUTPUT

VOLTAGE

0V

"CHARGE"

"DISCHARGE"

"CHARGE"

"DISCHARGE"

Vripple (mV)

V OUTAVG

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