{"id":6603,"date":"2025-07-21T00:00:00","date_gmt":"2025-07-21T00:00:00","guid":{"rendered":"https:\/\/lp.szlogic.cn\/glossary\/turns-ratio-in-lan-transformers\/"},"modified":"2026-06-22T08:54:07","modified_gmt":"2026-06-22T08:54:07","slug":"turns-ratio-in-lan-transformers","status":"publish","type":"post","link":"https:\/\/resources.l-p.com\/vi\/glossary\/turns-ratio-in-lan-transformers","title":{"rendered":"T\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y trong b\u1ed9 bi\u1ebfn \u00e1p LAN l\u00e0 g\u00ec?"},"content":{"rendered":"
\"What<\/figure>\n\n\n\n

\ud83e\uddf2<\/strong>T\u00ecm hi\u1ec3u v\u1ec1 t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y trong c\u00e1c th\u00e0nh ph\u1ea7n \u0111i\u1ec7n t\u1eeb Ethernet<\/h2>\n\n\n\n

The t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y<\/strong> trong b\u1ed9 bi\u1ebfn \u00e1p LAN\u2014c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 th\u00e0nh ph\u1ea7n \u0111i\u1ec7n t\u1eeb Ethernet<\/a>\u2014l\u00e0 m\u1ed9t th\u00f4ng s\u1ed1 thi\u1ebft k\u1ebf quan tr\u1ecdng x\u00e1c \u0111\u1ecbnh m\u1ed1i quan h\u1ec7 gi\u1eefa s\u1ed1 v\u00f2ng d\u00e2y (v\u00f2ng) tr\u00ean ph\u00eda s\u01a1 c\u1ea5p<\/strong> (ph\u00eda PHY) v\u00e0 ph\u00eda th\u1ee9 c\u1ea5p<\/strong> (ph\u00eda c\u00e1p) c\u1ee7a b\u1ed9 bi\u1ebfn \u00e1p. Th\u00f4ng s\u1ed1 n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c bi\u1ec3u th\u1ecb d\u01b0\u1edbi d\u1ea1ng m\u1ed9t t\u1ef7 l\u1ec7 nh\u01b0 1:1<\/strong> or 2.5:1<\/strong>, v\u00e0 \u1ea3nh h\u01b0\u1edfng tr\u1ef1c ti\u1ebfp \u0111\u1ebfn \u0111\u1ed9 to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u, ph\u1ed1i h\u1ee3p tr\u1edf kh\u00e1ng v\u00e0 kh\u1ea3 n\u0103ng t\u01b0\u01a1ng th\u00edch v\u1edbi C\u00f4ng ngh\u1ec7 Cung c\u1ea5p Ngu\u1ed3n qua Ethernet (PoE) trong c\u00e1c \u1ee9ng d\u1ee5ng Ethernet.<\/p>\n\n\n\n

\ud83e\uddf2<\/strong>T\u1ea1i sao t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y l\u1ea1i quan tr\u1ecdng trong b\u1ed9 bi\u1ebfn \u00e1p LAN?<\/h2>\n\n\n\n

1. Ph\u1ed1i h\u1ee3p tr\u1edf kh\u00e1ng<\/strong><\/h3>\n\n\n\n

M\u1ee5c \u0111\u00edch ch\u00ednh c\u1ee7a b\u1ed9 bi\u1ebfn \u00e1p trong m\u1ea1ch Ethernet l\u00e0 cung c\u1ea5p ph\u1ed1i h\u1ee3p tr\u1edf kh\u00e1ng<\/strong> gi\u1eefa PHY (IC l\u1edbp v\u1eadt l\u00fd) v\u00e0 c\u00e1p xo\u1eafn \u0111\u00f4i (th\u01b0\u1eddng c\u00f3 tr\u1edf kh\u00e1ng vi ph\u00e2n 100 \u03a9). T\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y 1:1 th\u01b0\u1eddng duy tr\u00ec s\u1ef1 c\u00e2n b\u1eb1ng tr\u1edf kh\u00e1ng n\u00e0y, \u0111\u1ea3m b\u1ea3o ph\u1ea3n x\u1ea1 t\u00edn hi\u1ec7u t\u1ed1i thi\u1ec3u v\u00e0 truy\u1ec1n c\u00f4ng su\u1ea5t t\u1ed1i \u0111a.<\/p>\n\n\n\n

2. Chuy\u1ec3n \u0111\u1ed5i \u0111i\u1ec7n \u00e1p v\u00e0 d\u00f2ng \u0111i\u1ec7n<\/strong><\/h3>\n\n\n\n

T\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y kh\u00e1c 1:1 cho ph\u00e9p \u0111i\u1ec1u ch\u1ec9nh m\u1ee9c \u0111i\u1ec7n \u00e1p v\u00e0 d\u00f2ng \u0111i\u1ec7n. V\u00ed d\u1ee5, m\u1ed9t t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y 2,5:1<\/strong> gi\u1ea3m \u0111i\u1ec7n \u00e1p theo h\u1ec7 s\u1ed1 2,5 \u0111\u1ed3ng th\u1eddi t\u0103ng d\u00f2ng \u0111i\u1ec7n t\u01b0\u01a1ng \u1ee9ng, \u0111i\u1ec1u n\u00e0y r\u1ea5t h\u1eefu \u00edch trong c\u00e1c \u1ee9ng d\u1ee5ng PoE<\/strong><\/a> (Cung c\u1ea5p Ngu\u1ed3n qua Ethernet)<\/strong> n\u01a1i c\u00e1c m\u1ee9c \u0111i\u1ec7n \u00e1p kh\u00e1c nhau ph\u1ea3i \u0111\u01b0\u1ee3c h\u1ed7 tr\u1ee3 qua r\u00e0o c\u1ea3n c\u00e1ch ly.<\/p>\n\n\n\n

3. C\u00e1ch ly t\u00edn hi\u1ec7u v\u00e0 b\u1ea3o v\u1ec7<\/strong><\/h3>\n\n\n\n

All Ethernet transformers<\/a>, b\u1ea5t k\u1ec3 t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y c\u1ee7a ch\u00fang, \u0111\u1ec1u cung c\u1ea5p c\u00e1ch ly galvanic<\/strong> (th\u01b0\u1eddng l\u00e0 1500 Vrms) gi\u1eefa PHY v\u00e0 c\u00e1p Ethernet b\u00ean ngo\u00e0i. \u0110i\u1ec1u n\u00e0y gi\u00fap b\u1ea3o v\u1ec7 c\u00e1c IC nh\u1ea1y c\u1ea3m kh\u1ecfi c\u00e1c \u0111\u1ee3t t\u0103ng \u0111i\u1ec7n \u00e1p, v\u00f2ng n\u1ed1i \u0111\u1ea5t v\u00e0 EMI<\/a>.<\/p>\n\n\n\n

\ud83e\uddf2<\/strong>C\u00e1c c\u1ea5u h\u00ecnh t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y ph\u1ed5 bi\u1ebfn<\/h2>\n\n\n\n
\n\n<\/colgroup>

Lo\u1ea1i \u1ee9ng d\u1ee5ng<\/p><\/th>

T\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y \u0111i\u1ec3n h\u00ecnh<\/p><\/th>

Ghi ch\u00fa<\/p><\/th><\/tr>

Ethernet 10\/100BASE-T<\/p><\/td>

1:1<\/p><\/td>

Ti\u00eau chu\u1ea9n cho Ethernet c\u0169<\/p><\/td><\/tr>

1000BASE-T (Gigabit)<\/p><\/td>

1:1 ho\u1eb7c c\u00f3 \u0111i\u1ec3m gi\u1eefa (center-tap)<\/p><\/td>

T\u1ed1i \u01b0u h\u00f3a cho t\u00edn hi\u1ec7u song c\u00f4ng (full-duplex)<\/p><\/td><\/tr>

PoE \/ PoE+ (802.3af\/at)<\/p><\/td>

2,5:1 ho\u1eb7c cao h\u01a1n<\/p><\/td>

H\u1ed7 tr\u1ee3 \u0111i\u1ec7n \u00e1p cao h\u01a1n \u1edf ph\u00eda c\u00e1p<\/p><\/td><\/tr>

Ethernet Multi-gig (2,5G\/5G\/10G)<\/p><\/td>

Ph\u1ee5 thu\u1ed9c v\u00e0o PHY<\/p><\/td>

Y\u00eau c\u1ea7u ph\u1ed1i h\u1ee3p & ch\u1eafn nhi\u1ec5u c\u1ea9n th\u1eadn<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n

\n

\ud83d\udccc V\u00ed d\u1ee5: B\u1ed9 bi\u1ebfn \u00e1p <\/span>LP5019NL<\/a> LAN 1G c\u1ee7a LINK-PP s\u1eed d\u1ee5ng t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y 1CT:1 nh\u1eb1m \u0111\u1ea3m b\u1ea3o t\u01b0\u01a1ng th\u00edch v\u1edbi c\u00e1c ti\u00eau chu\u1ea9n IEEE 802.3u v\u00e0 802.3ab.<\/span><\/p>\n<\/blockquote>\n\n\n\n

\"Turns<\/figure>\n\n\n\n

\ud83e\uddf2<\/strong>L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 ch\u1ecdn t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y ph\u00f9 h\u1ee3p?<\/h2>\n\n\n\n

Vi\u1ec7c l\u1ef1a ch\u1ecdn t\u1ef7 s\u1ed1 v\u00f2ng d\u00e2y \u0111\u00fang ph\u1ee5 thu\u1ed9c v\u00e0o nhi\u1ec1u y\u1ebfu t\u1ed1 \u1edf c\u1ea5p \u0111\u1ed9 h\u1ec7 th\u1ed1ng:<\/p>\n\n\n\n