Ntụgharị uche nwere ike ibute ụda. A na-egosiputa ụda mgbaama a na-ahụkarị na foto 1.

Yabụ kedu ka mgbaaka mgbaama si eme?

Dị ka e kwuru na mbụ, ọ bụrụ na a na-enwe mgbanwe nke impedance n’oge nnyefe mgbaàmà, ntụgharị uche ga-eme. Mgbama a nwere ike ịbụ mgbaama nke onye ọkwọ ụgbọ ala zitere, ma ọ bụ ọ nwere ike ịbụ mgbama gosipụtara na-egosipụta site na njedebe dị anya. Dị ka usoro ntụgharị uche si dị, mgbe mgbaàmà ahụ na-eche na impedance na-adị ntakịrị, ntụgharị uche na-adịghị mma ga-eme, na voltaji na-adịghị mma na-egosipụta ga-eme ka akara ngosi ahụ pụta. A na-egosipụta akara ngosi ọtụtụ oge n’etiti onye ọkwọ ụgbọ ala na ibu dịpụrụ adịpụ, nsonaazụ ya bụ mgbama na-akụ. Mmetụta mmepụta nke ọtụtụ ibe dị ala. Ọ bụrụ na mmepụta impedance bụ ihe na-erughị njirimara impedance nke PCB Chọpụta, ụda mgbaama ga-emerịrị ma ọ bụrụ na enweghị nkwụsị isi mmalite.

Enwere ike ịkọwa usoro mgbanaka mgbaama site na eserese bounce. Na-eche na mmepụta ihe mgbochi nke njedebe mbanye bụ 10 ohms, na njirimara njirimara nke PCB trace bụ 50 ohms (nwere ike gbanwee site na ịgbanwe obosara nke PCB trace, ọkpụrụkpụ nke dielectric n’etiti PCB trace na n’ime ntụaka. ụgbọ elu), maka ịdị mma nke nyocha, were ya na njedebe dịpụrụ adịpụ na-emeghe , Ya bụ, njedebe dị anya na-enweghị njedebe. Ọgwụgwụ mbanye na-ebunye mgbama voltaji 3.3V. Ka anyị soro akara ngosi ahụ wee banye n’ahịrị nnyefe a otu ugboro ka anyị hụ ihe merenụ. Maka ịdị mma nke nyocha, a na-eleghara mmetụta nke capacitance parasitic na parasitic inductance nke eriri nnyefe, na-atụle naanị ibu ndị na-eguzogide. Onyonyo 2 bụ schematic eserese nke ntụgharị uche.

Nleghachi nke mbụ: a na-eziga mgbaàmà ahụ site na mgbawa, mgbe 10 ohm mmepụta impedance na 50 ohm PCB njirimara impedance, mgbaàmà n’ezie agbakwunyere na PCB trace bụ voltaji na ebe A 3.3 * 50 / (10 + 50) = 2.75 V. Ntufe na ebe dịpụrụ adịpụ B, n’ihi na isi B na-emeghe, nkwụsịtụ enweghị njedebe, na ọnụọgụ ntụgharị bụ 1, ya bụ, akara ngosi niile na-egosipụta, na akara ngosi na-egosipụtakwa 2.75V. N’oge a, voltaji a tụrụ na isi B bụ 2.75 + 2.75 = 5.5V.

Ntụle nke abụọ: voltaji nke 2.75V na-atụgharị na-alaghachi n’ókè A, nkwụsịtụ na-agbanwe site na 50 ohms gaa na 10 ohms, ntụgharị uche na-adịghị mma na-eme, voltaji na-egosipụta na ebe A bụ -1.83V, voltaji ahụ rutere n’ókè B, na ntụgharị uche na-eme ọzọ, na voltaji a na-egosipụta bụ -1.83 V. N’oge a, voltaji a tụrụ na isi B bụ 5.5-1.83-1.83 = 1.84V.

Ntụle nke atọ: Voltage-1.83V gosipụtara site na isi B ruru ebe A, ntụgharị uche na-adịghị mma na-apụtakwa ọzọ, na voltaji a na-egosipụta bụ 1.22V. Mgbe voltaji ahụ rutere n’ókè B, ntụgharị uche mgbe niile na-eme ọzọ, na voltaji a na-egosipụta bụ 1.22V. N’oge a, voltaji a tụrụ na isi B bụ 1.84 + 1.22 + 1.22 = 4.28V.

N’ime okirikiri a, voltaji a na-egosipụta na-agbaghachi azụ na azụ n’etiti isi A na isi B, na-eme ka voltaji dị na isi B ghara ịdị n’otu. Lelee voltaji na isi B: 5.5V-> 1.84V-> 4.28V->……, enwere ike ịhụ na voltaji na ebe B ga-agbanwe elu na ala, nke bụ ụda mgbaàmà.

Kedu ka ụda mgbaama na sekit PCB si eme?

Ihe kpatara mgbaama mgbaama na-akpata site na ntụgharị uche na-adịghị mma, onye na-eme ihe ọjọọ ka bụ mgbanwe mgbanwe, nke bụ ihe mgbochi ọzọ! Mgbe ị na-amụ ihe gbasara iguzosi ike n’ezi ihe, ṅaa ntị mgbe niile na nsogbu impedance.

Mkpọkpọ mgbaama na njedebe ibu ga-egbochi nke ukwuu na nnabata mgbaama wee kpatara njehie mgbagha, nke a ga-ebelata ma ọ bụ kpochapụ. Ya mere, a ga-emerịrị nkwụsị nke impedance maka ahịrị nnyefe ogologo.