VD5377 datasheet(7/88 Pages) STMICROELECTRONICS

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Doc ID 022952 Rev 2

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VD5377

Overview

The VD5377 is an ultra-low power, single-chip controller IC containing all the functions

necessary for optical joysticks/optical finger navigation modules. It incorporates a 20 x 20,

30.4 µm pixel imaging array supporting frame rates up to 4 k frames/s capable of detecting

and tracking motion at up to 28 inches/s with high accuracy and low drift. Maximum velocity

is calculated as follows:

maximum velocity = (pixel size/lens magnification) x max frame rate x

max.displacement per frame

For example:

0.5 magnification = (30 µm/0.5) x 4000 f/s x 3 pixels = 0.72 m/s (28

inches/s)

Figure 1 shows a simplified block diagram of a typical optical navigation system.

Communication with the device is over a 400 kHz I2C serial link (I2C address is user-

selectable). The MOTION signal is asserted when the VD5377 senses motion and motion

X/Y data is accessed over the I2C link. The user can choose between Automatic power

management mode, where the device will automatically go into low power hibernation if no

motion is detected or Manual power management mode where there is a choice of two low

power states: Standby or Powerdown. The external navigation LED driver is fully integrated

in the device, supporting drive currents up to 14 mA. Where higher power is required, an

external driver can be used.

Figure 1. VD5377 simplified system block diagram

IR LED

LED_OUT

2.2 to 3.0V

VD5377

I2C

MOTION

POWERDOWN

STANDBY

Host MCU

VD5377 数据表(PDF) 7 Page - STMicroelectronics