L9803 datasheet(68/126 Pages) STMICROELECTRONICS

Part #	L9803

Description	Super smart power motor driver with 8-Bit MCU, RAM, EEPROM, ADC, WDG, Timers, PWM and H-bridge driver

PDF	126 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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68 / 126 page

On-Chip Peripherals

L9803

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Figure 33.

Impedance at PWMO/I pin

5.4.3

PWMI

PWMI is an input line, directly connected to PB2 bit. The circuit translates the voltage levels

referred to VB voltage supply to the internal logic levels (see Figure 32). When the voltage

on PWMI pin is higher than VB/2 PB2 reads an high logic level.

If the bit PWMI in DCSR register is set (see Section 3.2.1), PWMI is directly connected with

the Input Capture 2 on Timer 2, which is otherwise connected in alternate function to PA7

(see Figure 34).

An internal pull down current generator (5µA) allows to detect the Open Bus condition

(external pull up missing).

If the battery or ground connection are lost, the PWMI line shows a controlled impedance

characteristic (see Figure 34).

Figure 34.

PWMI function

Describe the register DCSR (0022h) as reported in Table 1.

50K

Ω

50K

Ω

µA

14V

TIMER 2

ICAP2

PIEN

DCSR

PWM

I/O

PWM INPUT

PA(7) ALTERNATE INPUT

PORT

PWMI

PA7

PA(7)

PB(2)

L9803 Datasheet(PDF) 68 Page - STMicroelectronics