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AN3419

Navigation

Doc ID 018955 Rev 1

7/16

Figure 11.

Manual Swipes - bad (jittery) navigation

www.BDTIC.com/ST

Summary of Contents for VD5376

Page 1: ...OFN devices 2 Initialization The initialization setup depends on the customer application for example automatic or manual power mode direct 1v8 drive or Vtop supply CPI setting X Y direction and so o...

Page 2: ...aces STMicroelectronics suggested non finger surfaces for OFN testing are white card cotton and leather glove Care must be taken when choosing surfaces for XY table testing as the module surface can b...

Page 3: ...ot essential The images Figure 5 and Figure 6 show what is and what is not Figure 7 and Figure 8 considered acceptable OFN navigation plots below were done at 4ips Figure 5 OFN good navigation Figure...

Page 4: ...r setting Figure 6 navigation although too small is circular The X Y CPI register settings can both be increased here to achieve the required CPI value Figure 7 shows glitchy navigation while the navi...

Page 5: ...the real navigation testing is done by fingers It is very important to test a wide range of users fingers to find the best and worst fingerprints The image below shows good finger navigation The modu...

Page 6: ...Navigation AN3419 6 16 Doc ID 018955 Rev 1 Figure 10 Manual finger swipes bad navigation www BDTIC com ST...

Page 7: ...AN3419 Navigation Doc ID 018955 Rev 1 7 16 Figure 11 Manual Swipes bad jittery navigation www BDTIC com ST...

Page 8: ...cal current consumption on a VD5376 Automatic power management mode should not be used with VD5376 in applications with more than one device on the I2 C bus Table 1 VD5377 typical current consumption...

Page 9: ...nload over I2 C AN3415 VD5376 image download over I2 C 018944 AN3414 VD5377 image download over I2 C 018941 Fast image streaming AN3417 VD5376 OFN high speed imaging system 018949 AN3418 VD5377 OFN hi...

Page 10: ...n real time Although four extra test pins are required on the OFN module for this test mode See application notes AN3417 and AN3418 for more details In both Figure 14 and Figure 15 the image download...

Page 11: ...AN3419 Images Doc ID 018955 Rev 1 11 16 Figure 15 VD5376 ST image download application 0 75x optics www BDTIC com ST...

Page 12: ...sible without any features In Figure 16 there is nothing on the module The image should be completely black but we can see that there is light leaking onto the sensor from the LED In Figure 17 there i...

Page 13: ...Images Doc ID 018955 Rev 1 13 16 Figure 18 shows a good image of Blu Tack Figure 19 shows a good image of a fingerprint Figure 18 Blu Tack flat centred image good Figure 19 Fingerprint good www BDTIC...

Page 14: ...ST imaging light sources Schott KL1500 LCD light as shown in Figure 20 6 3 1 Navigation with bright external light A 150W halogen light source with IR filter removed and light pipe is used to illumin...

Page 15: ...AN3419 Revision history Doc ID 018955 Rev 1 15 16 7 Revision history Table 3 Revision history Date Revision Changes 04 Oct 2011 1 Initial release www BDTIC com ST...

Page 16: ...OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION OR INFRINGEMENT OF ANY PATENT COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT UNLESS EXPRES...

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