VD5377 datasheet(46/88 Pages) STMICROELECTRONICS

Nome de Peças	VD5377

Descrição Electrónicos	Ultra-low power motion sensor for optical finger navigation (OFN)

PDF	88 Pages

Scroll/Zoom	100%

Fabricante Electrônico	STMICROELECTRONICS [STMicroelectronics]

Página de início	http://www.st.com

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46 / 88 page

Additional features

VD5377

46/88

Doc ID 022952 Rev 2

7.3.1

PWM operation

The following list is a summary of PWM operation (Figure 19).

•

The PWM block is clocked by the internal 50 kHz oscillator which means in STANDBY

state in MANUAL power mode and in SLEEP states in AUTOMATIC power mode the

backlight LEDs are still running.

•

Maximum LED period is 5.12 ms (256 x OSC50K clock period).

•

Programmable pulse width (from 0 to 5.12 ms).

•

BACKLED pulses can be “gated” or “delayed” during the tracking LED “on” time to

avoid interference with the tracking function. This should not be required if the

BACKLED are shielded.

Note:

No test is performed on pulsehigh value versus period value so the host must ensure that

pulsehigh < period.

Figure 19. PWM operation: three independent PWM channels

backled_en

Osc

50kHz

period

pulsehigh1

pulsehigh0

pulsehigh2

pwm0

pwm1

pwm2

VD5377 Folha de dados(PDF) 46 Page - STMicroelectronics