Description (continued)

VT5365

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Description (continued)

The VT5365 has been optimized for low power operation enabling long battery life, achieved

by either a single 1.8V or 2.0 V to 3.2 V supply.

The on-chip regulators allow for a wide range of power supply taken from 2 batteries in

series, enabling a low cost BOM. However, for the most efficient power consumption, the

regulators can be bypassed so that the chip is driven at the minimal supply of 1.8V by an

external power source (typically a DC/DC convertor from a single cell voltage). In both

cases, an on-chip DCDC regulator controls the LED, so that only a single 1.8V supply is

required for the overall application. The supply scheme is selected by connecting an IO to

GND or VDD.

Care has been taken to implement ultra-low power idle/sleep modes with wake-ups at

programmable periods and/or external events enabling very long battery life. It is estimated

that with a typical user and 2 x AA Alkaline batteries configured in parallel a useful battery

lifetime of 9 months can be achieved.

STMicroelectronics default firmware supports 5 buttons, mechanical Z-Wheel, low battery

level detect/indicate output and internal DC/DC controller to supply the navigation LED.

The firmware generates baseband 4.8kbps, Manchester coded data with RF on signal for

standby.

The output can be selected as either baseband RF serial data, or 27.045MHz FSK digitally

modulated signal. In this case, very minimal external circuitry is required for filtering and

amplification, and the overall system can be achieved using a single 12MHz Xtal.

This firmware may be replaced allowing customers to build in their own features for their

particular mouse (including 2 extra GPIO).

The VT5365 sensor will operate over a wide range of illuminant wavelengths and is suitable

for use with visible, IR and laser light sources.

Figure 1.

VT5365 block diagram

TRK_LED

Pixel Array

365 Core

12 MHz

Buttons

Vdd (1.8V)

LED control

VT5365

Power

SDA

SCL

Optional

EEPROM

Power Management

RFON

RFOUT

X1

X0

GPIO1-7

Z-wheel

GPIO 0

LO BATT

SGPIO 0

SGPIO 1

PSU

Select

VGATE

VLED

VHIGH

27MHz

passive LC filter

1.8V Single Stage

amplifier

Single Cell Voltage