VT5366_06 STMICROELECTRONICS | Alldatasheet
Document overview
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Technical content
Datasheet sections
- 1 Introduction
- 2 Functional block diagram
- 3 Design notes
- 3.1 Pin assignment
- 3.2 Optical centre
- 3.3 Sensor orientation on PCB
- 3.4 Driving the navigation LED
- 4 Wireless reference design board
- 4.1 Pin description
- 4.2 Bill of materials
- 5 Operation
- 5.1 I2C communication
- 5.2 Register map
- 5.2.1 Read motion
- 5.2.2 Customer access
- 5.3 Initialization
- 5.4 Reading the X any Y motion vectors
- 5.5 Operating mode
- 5.6 Motion sensitivity in non RUN modes
- 5.7 Overall system performance
- 6 Serial control bus
- 6.1 General description
- 6.2 Serial communication protocol
- 6.2.1 Data format
- 6.2.2 Message interpretation
- 6.3 T ypes of messages
- 6.3.1 Single location, single data write
- 6.3.2 Multiple location write
Features
■ Pin compatible with VT5364 ■ Can be used (with external MCU) in all optical mouse applications ■ Single +1.8V Supply ■ Very low power operation, enabling long battery life ■ CPI programmable up to 3200 (default 800 cpi) ■ Up to 9,375 frames per second ■ Tracking at up to 40 ips ■ I2C interface ■ On-chip ADC for voltage level reporting ■ Proven, high volume package technology - smallest package currently available on market ■ Minimal external circuitry ■ Low battery indicator ■ Suitable for use with both LED and laser (VCSEL) light sources ■ Reference Designs available ■ Applications: USB/PS2, Wireless & Bluetooth optical mice
Description
The VT5366 has been designed for pin to pin compatibility with the VT5364 (a) and is STMicroelectronics first generally available chip for use in all optical mice applications: Wired - USB (Low and Full Speed) and PS2; Wireless - 27MHz/2.4GHz and BlueTooth. The device has been designed to provide long battery life whilst enabling excellent navigation control and precision on a wide range of surfaces. Housed in the smallest, currently available, package (7mmx7mm), the chip is suitable for use in small form-factor mice demanded by laptop users. Minimal external circuitry is required thereby reducing BOM and assembly costs. The VT5366 sensor will operate over a wide range of illuminant wavelengths. For devices operating at approx 850nm (IR LED or VCSEL), the on-die automatic exposure controller (AEC) will compensate for the change in sensitivity compared to 640nm (red LED). Motion performance can be improved by increasing the current supplied to the navigation LED. A specifically designed LED optical system with integrated light guide and lens is available along with an aperture piece which clips the package in place aligning the optics. This has been optimized for low cost, space saving and ease of assembly in high volume mouse manufacture. No kapton tape is required in the assembly process. Please contact STMicroelectronics for supplier details. Technical specifications a. To make use of the new battery level function the PCB and firmware will need to be modified Resolution CPI programmable up to 3200. Default 800 CPI Pixel size 30.4 µm Array size 20*20 pixels Frame rate Up to 9,375 frames/second High speed motion detector Accurate motion up to 40 ips Clock 6MHz Supply voltage 1.8V Supply current RUN (9.6Kfps) - 9mA Power Down - 10µA typ. excluding LED Operating temperature [0: 60] °C Package type 7*7mm 32 lead LOQFP (Low profile Optical Quad Flat Pack)
1 Introduction
The VT5366 sensor is a single-chip solid state optical tracking engine with no moving parts. and precision, works on a wide range of surfaces. and LED are included in this document. Figure 1. STV-366-R01 reference design mouse.
2 Functional block diagram
Figure 2. Block diagram
3 Design notes
3.1 Pin assignment
Figure 3. VT5366 pin assignment
3.2 Optical centre
Figure 4. The PCB designer must take this into account when laying out the
Figure 4. VT5366 optical centre
3.3 Sensor orientation on PCB
correct directions when the mouse is moved. This is shown in Figure 5. Figure 5. VT5366 optical centre
3.4 Driving the navigation LED
The VT5366 provides an output (TRK_LED) to drive the LED that is used to illuminate the mousing surface. This output is active HIGH but cannot be used to drive the navigation LED directly. An external NPN bipolar transistor is recommended as shown in the reference schematic ( Figure 6). The maximum current through the LED is controlled by a resistor (R1 on the Reference Schematic). Note: The navigation LED, controlled by the VT5366, is used in a non-continuous mode. The duty cycle of the LED is varied by the exposure controller inside the VT5366 and has a maximum value of 40 % (on very dark surfaces).
4 Wireless reference design board
Figure 6. Wireless reference schematic
4.1 Pin description
Table 1. VT5366 pin description
2 VLevel CMP Battery voltage detection input
3 Test_Out I/O No Connect
5 X0 OSC 6MHz resonator
7 XI OSC 6MHz resonator
9 DGND1 PWR Digital Ground
18 TRK_LED I/O Navigation LED Output
20 DGND2 PWR Digital Ground
21 SDA I/O I2C SDA Line
22 SCL I/O I2C SCL Line
23 POWERDOWN I/O Wake up
24 MOTION I/O Motion detect
32 AVSS PWR Analog Ground
4.2 Bill of materials
Table 2. Bill of materials: main components
366 Block
5 Operation
takes place over a standard I2C bus.
5.1 I2C communication
5.2 Register map
5.2.1 Read motion
The key registers that are required are listed below.
5.2.2 Customer access
The rest of the customer accessible registers are listed below. Table 3. Key register Table 4. Reg [#0x00 - 0x01] Device revisions
Table 5. Reg [#0x05] - IO_Control HIGH, otherwise sets it low. Table 6. Reg [#0x20]: Clear_Motion out motion from the integrator. Table 7. Reg [#0x21]: X_motion Value is 8 bit 2’s complement.
Table 8. Reg [#0x22]: Y_motion Value is 8 bit 2’s complement. Table 9. Reg [#0x23] Overflow / No motion Table 10. Reg [#0x27]: Motion Directions & Polarities
0 Allows X to be inverted
Table 11. Reg [#0x29]: Minimum Features Table 12. Reg [#0x2A]: Motion resolution: Count/Inch
Table 13. Reg [#0x2F]: Minimum Motion Search Vector Table 14. Reg [#0x31 - 0x32]: Surface Feature Report Table 15. Reg [#0x40 - 0x41]: Exposure Setting Table 16. Reg [#0x43]: AutoExposure Enable Table 17. Reg [#0x47] : ADC data Table 18. Reg [#0x4F]: Exposed image Max reported value
5.3 Initialization
It is recommended that the VT5366 autoclear function is activated during a read. To do this the processor should write the value 0x02 to register 0x20 after enabling the VT5366 (by setting PowerDown LOW). This only needs to be done once after the power supply has been applied.
5.4 Reading the X any Y motion vectors
It is recommended that the processor reads the motion data at a rate of around every 2ms. The X and Y motion information is read using a single I2C ‘multiple read’ transaction. The sequence is as follows; (1) Read I2C registers 0x21 (contains X-motion) and 0x22 (contains Y -motion). Note that these two registers MUST be read with a single I2C ‘multiple read’ transaction. See Chapter 6. As shown above X and Y motion vectors can be read from registers 0x21 and 0x22. The values are in 2’s complement notation to allow positive and negative motion to be represented. The values read represent the accumulated motion since the last time the registers were read. As soon as the registers have been read they will automatically be reset to 0 and the Motion Detect output (pin 24) will go LOW.
5.5 Operating mode
The VT5366 itself has only two operating modes; ON - when PowerDown = 0 and OFF - when PowerDown = 1 Overall system behavior is controlled by the external microprocessor which can switch the VT5366 on and off with various duty cycles. Typical operation is described below. 1. The processor enables the VT5366 by setting PowerDown (pin 23) LOW. 2. The processor delays for T on (typically 250µs) to allow some frames to be captured. 3. The processor then monitors Motion Detect to see if motion has occurred. If Motion Detect (pin 24) = 0 then no motion has been detected and the VT5366 can be put back to sleep by setting PowerDown HIGH. 4. The processor then waits for a time T sleep and returns to step (1). 5. If motion IS detected at step (3) i.e. Motion Detect = 1 then the motion vectors are read over the I2C interface. The processor can then monitor Motion Detect again to see if further motion has occurred.
5.6 Motion sensitivity in non RUN modes
Before going into a non-run mode write 0x40 to register 0x2F (ie. when the mouse goes into idle mode), this will make the motion engine more sensitive to frame change at lower non- run frame rates on low contrast surfaces. When waking up (on motion detect) re-write the default 0x10 to register 0x2F to maintain running motion accuracy.
5.7 Overall system performance
The overall performance of a wireless mouse system depends on many different factors including: – Battery choice – Power supply design – Choice of external microprocessor – Design of firmware running in external processor – Design of external RF transmission circuitry – User model i.e. how much time the mouse is actually being used and surface type. Note: See Applications Note AN2473 for details on Optical Wireless Mouse Design using the VT5366.
6 Serial control bus
6.1 General description
The 2-wire I2C serial interface bus is used to read and write the VT5366 registers.
6.2 Serial communication protocol
Figure 7. Serial Interface data transfer protocol
6.2.1 Data format
when sda falls or rises respectively, while scl is high. Figure 8. VT5366 serial interface address
to as the index). The serial interface can address up to 256 byte registers. Figure 9. Serial interface data format (write ex)
6.2.2 Message interpretation
data, sampled from sda, can be interpreted. stop condition or sends a repeated start, (Sr). stored in the internal register addressed by the current index. master requests a read from the sensor.
6.3 Types of messages
– Multiple location writes may be used for faster information transfers. while this bit is set in the read address.
6.3.1 Single location, single data write
When a random value is written to the sensor, the message looks as shown in Figure 10. Figure 10. Single location, single write
6.3.2 Multiple location write
assumed if no stop condition occurs. Figure 11. Multiple location write
6.3.3 No data write followed by same location read
gain value (index = 36) is read as 15. Figure 12. No data write followed by same location read SDA would be held low and the master would not be able to issue a STOP .
6.3.4 Multiple data read
Figure 13. Multiple data read rise, which is part of the stop condition.
7 Optics assembly
The optics assembly is shown in Figure 14 and Figure 15. Figure 14. MaxEmil optics
Figure 15. 2D assembly drawing of the VT5366 (exploded view) written permission of STMicroelectronics.
7.1 Mouse assembly guidelines
- Attach the sensor and all other electrical components onto the PCB with the exception of the navigation LED. 2. Form the LED leads and insert the LED into the optical assembly. 3. Fit the optics/aperture to the PCB using the guideposts. Take care to keep contamination off the sensor surface. The sensor aperture should self-align to the VT5366V032 package. 4. Feed the navigation LED leads through their openings and solder the navigation LED leads and trim. 5. Fit the base plate. 6. Fit mouse top case and feet. Note: For more details on the Optics (including Manufacturer details) please refer to the STV-366-R0X User Manuals
8 LED selection
8.1 Overview
There are a number of LEDs from a range of suppliers which will work well with the VT5366.
8.2 Key LED parameters
forward current of 20mA. The key LED parameters are listed in Table 19.
8.3 VCSEL & IR Illumination
(AEC) will compensate for the change in sensitivity compared to 640nm (red LED). Navigation performance may be improved by increasing the illuminated device drive. Table 19. Key LED parameters
9 Electrical characteristics
9.1 Typical operating conditions
9.2 Logic IO
Note: All digital inputs/outputs are 1.8V capable, 5V tolerant. Table 20. Operating conditions Table 21. Digital IO electrical characteristics
Note: 1 Surface finish W1 is 0.07 Ra. 2 Ejectors are on 5.2 mm square for both top and bottom package. 3 On top package, only the identification for pin one is not an engraved ejector.
10.1 LOQFP package guidelines
having a temperature profile peak of no higher than 240 ° C. The package/chip are lead free and is ROHS compliant. For full handling guidelines please contact ST (doc no. 7310623). Table 22. LQFP dimensions (mm)
Table 23. Order codes 19-Dec-2006 1 Initial release.