AK4182A Datasheet, PDF (9/18 Pages) Asahi Kasei Microsystems – Touch Screen Controller

ASAHI KASEI
ON
YP


ON
[AK4182A]
YP
XP
VREF+
AIN+
ADC
VREF-
AIN-
XN
ON
YN
touch
XP
VREF+
AIN+
ADC
VREF-
AIN-
XN
ON
YN
touch
a) Z1-Position Measurement Differential Mode
b) Z2-Position Measurement Differential Mode
Figure 3 චѹଌఆճ࿏
ج ■४ిѹݯʢVREFʣ
AK4182A ͸ɺ2.5V ग़ྗͷج४ిѹݯΛ಺ଂ͍ͯ͠·͢ɻ͜ͷ಺ଂ VREF ͸ɺ੍ޚίϚϯυͷ PD1 bit Λ “1” ʹઃఆ͢Δ
ͱɺύϫʔΞοϓ͠ɺ “0” ʹઃఆ͢Δͱύϫʔμ΢ϯ͠·͢ɻ͜ͷ಺෦ج४ిѹݯΛ༻͍ͯɺλονεΫϦʔϯͷγϯ
άϧΤϯυଌఆΛߦ͏৔߹΍ɺόοςϦిѹ͓ΑͼԹ౓ଌఆ࣌͸ɺ༧Ί PD1 bit Λ “1” ʹઃఆ͢Δඞཁ͕͋Γ·͢ɻ
VREF ճ࿏ͷ҆ఆੑΛ֬อ͢ΔͨΊɺVREF pin ʹ 0.1μF Ҏ্ͷίϯσϯαΛ઀ଓͯ͠Լ͍͞ɻVREF ͷ্ཱ͕ͪΓ࣌ؒ
͸ɺ֎෇͚ίϯσϯαͷ஋ʹґଘ͠·͕͢ɺ0.1μF Λ઀ଓͨ͠৔߹ɺητϦϯά࣌ؒͱͯ͠ 500μs ఔ౓औ͍ͬͯͩ͘͞ɻ
֎෦͔Βج४ిѹΛೖྗ͢Δ৔߹͸ɺPD1 bit Λ “0” ʹͯ͠Լ͍͞ɻ
·ͨɺ಺ଂج४ిѹݯΛ࢖༻͢Δ৔߹͸ɺిిݯѹ͸ 2.7V Ҏ্ʹͯ͠Լ͍͞ɻ
■ όοςϦిѹͷଌఆ
AK4182A͸ɺిిݯѹ͕ 2.2~3.6Vͷঢ়ଶͰɺϦν΢ϜΠΦϯόοςϦ౳ 5V·ͰͷిѹΛ௚઀VBAT pinʹೖྗ͠ଌఆ͢
Δ͜ͱ͕ՄೳͰ͢ɻFigure 4ʹࣔ͢௨ΓVBATೖྗిѹ͸಺෦ͰR1ɺR2ʢ7.5kɺ2.5kʣͷ఍߅ʹΑΓ෼ׂ͞Ε·͢ɻ τϥ
οΩϯά࣌ؒ͸ɺόοςϦͷιʔεΠϯϐʔμϯε(R0)ʹґଘ͠·͕͢ɺগͳ͘ͱ΋ 5μsఔ౓औ͍ͬͯͩ͘͞ɻ
VBAT
R0
R1=7.5K
R2=2.5K
Internal
VREF(2.5V)
PD1
VREF
AIN+
VREF+
ADC
AIN-
VREF-
Enable
Figure 4
όοςϦిѹଌఆճ࿏

MS0482-J-01




2007/12