Lihat semua

Sila rujuk versi bahasa Inggeris sebagai versi rasmi kami.Kembali

Eropah
France(Français) Germany(Deutsch) Italy(Italia) Russian(русский) Poland(polski) Czech(Čeština) Luxembourg(Lëtzebuergesch) Netherlands(Nederland) Iceland(íslenska) Hungarian(Magyarország) Spain(español) Portugal(Português) Turkey(Türk dili) Bulgaria(Български език) Ukraine(Україна) Greece(Ελλάδα) Israel(עִבְרִית) Sweden(Svenska) Finland(Svenska) Finland(Suomi) Romania(românesc) Moldova(românesc) Slovakia(Slovenská) Denmark(Dansk) Slovenia(Slovenija) Slovenia(Hrvatska) Croatia(Hrvatska) Serbia(Hrvatska) Montenegro(Hrvatska) Bosnia and Herzegovina(Hrvatska) Lithuania(lietuvių) Spain(Português) Switzerland(Deutsch) United Kingdom(English)
Asia/Pasifik
Japan(日本語) Korea(한국의) Thailand(ภาษาไทย) Malaysia(Melayu) Singapore(Melayu) Vietnam(Tiếng Việt) Philippines(Pilipino)
Afrika, India dan Timur Tengah
United Arab Emirates(العربية) Iran(فارسی) Tajikistan(فارسی) India(हिंदी) Madagascar(malaɡasʲ)
Amerika Selatan / Oceania
New Zealand(Maori) Brazil(Português) Angola(Português) Mozambique(Português)
Amerika Utara
United States(English) Canada(English) Haiti(Ayiti) Mexico(español)
RumahProdukKristal, Pengayun, Resonatorsresonator

resonator

Produk 194 dijumpai

Senarai produk

1234
Bandingkan Gambar Bahagian # Pengeluar Penerangan Inventori Model ECAD RoHS Pakej Nombor produk asas Siri kekerapan Toleransi kekerapan kestabilan Pakej / Kes kemuatan Tinggi ciri-ciri galangan Jenis Saiz / Dimensi pemasangan Jenis Suhu Operasi kekerapan Kuantiti
CSTCE16M8V53-R0 CSTCE16M8V53-R0 Murata Electronics CERAMIC RES 16.8000MHZ 15PF SMD Dalam stok737000 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.2% 3-SMD, Non-Standard 15 pF 0.031" (0.79mm) Built in Capacitor - Ceramic 0.126" L x 0.051" W (3.20mm x 1.30mm) Surface Mount -20°C ~ 80°C 16.8 MHz
RO3101A RO3101A RFMi RESONATOR,SM,433.920 MHZ Dalam stok65380 pcs Tape & Reel (TR) RO3101 - ±75kHz 32ppb 4-SMD, No Lead - 0.063" (1.60mm) - - SAW 0.197" L x 0.138" W (5.00mm x 3.50mm) Surface Mount -40°C ~ 85°C 433.92 MHz
CSTNE16M0V530000R0 CSTNE16M0V530000R0 Murata Electronics CERAMIC RES 16.0000MHZ 15PF SMD Dalam stok357280 pcs Tape & Reel (TR) CSTNE CERALOCK® CSTNE ±0.5% ±0.3% 3-SMD, Non-Standard 15 pF 0.039" (1.00mm) Built in Capacitor 40 Ohms Ceramic 0.126" L x 0.051" W (3.20mm x 1.30mm) Surface Mount -40°C ~ 85°C 16 MHz
CSTCE12M0GH5L99-R0 CSTCE12M0GH5L99-R0 Murata Electronics CERAMIC RES 12.0000MHZ 33PF SMD Dalam stok225300 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.07% 3-SMD, Non-Standard 33 pF 0.039' (1.00mm) Built in Capacitor - Ceramic 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount 0°C ~ 70°C 12 MHz
PBRC4.19HR50X000 PBRC4.19HR50X000 KYOCERA AVX CERAMIC RES 4.1900MHZ 30PF SMD Dalam stok483800 pcs Tape & Reel (TR) - PBRC-H, Kyocera ±0.5% ±0.5% 3-SMD, Non-Standard 30 pF 0.079' (2.00mm) Built in Capacitor - Ceramic 0.291' L x 0.134' W (7.40mm x 3.40mm) Surface Mount -40°C ~ 85°C 4.19 MHz
CSTCR6M29G55B-R0 CSTCR6M29G55B-R0 Murata Electronics CER RESONATOR Dalam stok196040 pcs Tape & Reel (TR) CSTCR CERALOCK® CSTCR ±0.5% ±0.15% 3-SMD, Non-Standard 39 pF 0.047" (1.20mm) Built in Capacitor 50 Ohms Ceramic 0.177" L x 0.079" W (4.50mm x 2.00mm) Surface Mount -40°C ~ 125°C 6.29 MHz
CCR20.0MXC7T CCR20.0MXC7T TDK Corporation CERAMIC RES 20.0000MHZ 9PF SMD Dalam stok282800 pcs Tape & Reel (TR) - CCR ±0.5% ±0.2% 3-SMD, Non-Standard 9 pF 0.047' (1.19mm) Built in Capacitor 40 Ohms Ceramic 0.098' L x 0.079' W (2.50mm x 2.00mm) Surface Mount -40°C ~ 85°C 20 MHz
CSTCE8M00G52-R0 CSTCE8M00G52-R0 Murata Electronics CERAMIC RES 8.0000MHZ 10PF SMD Dalam stok110500 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.2% 1206 (3216 Metric) 10 pF 0.031" (0.79mm) Built in Capacitor - Ceramic 0.126" L x 0.051" W (3.20mm x 1.30mm) Surface Mount -20°C ~ 80°C 8 MHz
RO3164E-2 RO3164E-2 Murata Electronics SAW RES 868.3500MHZ SMD Dalam stok439500 pcs Tape & Reel (TR) RO31 - ±100kHz 0.032ppm 6-SMD, No Lead - 0.054" (1.38mm) - 1 MOhms SAW 0.118" L x 0.118" W (3.00mm x 3.00mm) Surface Mount -40°C ~ 125°C 868.35 MHz
FCR4.0MC5 FCR4.0MC5 TDK Corporation CERAMIC RES 4.0000MHZ 30PF T/H Dalam stok896000 pcs Bulk - FCR ±0.5% ±0.3% Radial - 3 Lead, 2.50mm Pitch 30 pF 0.256' (6.50mm) Built in Capacitor 20 Ohms Ceramic 0.374' L x 0.197' W (9.50mm x 5.00mm) Through Hole -40°C ~ 85°C 4 MHz
RO3164E-2 RO3164E-2 RFMi RESONATOR,SM,868.350 MHZ Dalam stok55040 pcs Tape & Reel (TR) RO3164 - ±100kHz 32ppb 6-SMD, No Lead - 0.054" (1.38mm) - - SAW 0.118" L x 0.118" W (3.00mm x 3.00mm) Surface Mount -40°C ~ 125°C 868.35 MHz
CSTCR4M00G53A-R0 CSTCR4M00G53A-R0 Murata Electronics CER RESONATOR SMD Dalam stok534800 pcs Tape & Reel (TR) CSTCR * - - 3-SMD, Non-Standard - 0.047" (1.19mm) - - - 0.177" L x 0.079" W (4.50mm x 2.00mm) Surface Mount - -
RO3103A RO3103A Murata Electronics SAW RES 418.0000MHZ SMD Dalam stok793300 pcs Tape & Reel (TR) RO31 - ±75kHz ±0.032ppm 4-SMD, No Lead - 0.063" (1.60mm) - - SAW 0.197" L x 0.138" W (5.00mm x 3.50mm) Surface Mount -40°C ~ 125°C 418 MHz
CSTCE20M0V13C99-R0 CSTCE20M0V13C99-R0 Murata Electronics CERAMIC RES 20.0000MHZ 15PF SMD Dalam stok241100 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.1% ±0.2% 3-SMD, Non-Standard 15 pF 0.031' (0.79mm) Built in Capacitor - Ceramic 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount -40°C ~ 125°C 20 MHz
CSTCE16M0V53-R0 CSTCE16M0V53-R0 Murata Electronics CERAMIC RES 16.0000MHZ 15PF SMD Dalam stok53600 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.3% 3-SMD, Non-Standard 15 pF 0.039' (1.00mm) Built in Capacitor - Ceramic 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount -20°C ~ 80°C 16 MHz
CSTCE10M0G52-R0 CSTCE10M0G52-R0 Murata Electronics CERAMIC RES 10.0000MHZ 10PF SMD Dalam stok174700 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.2% 1206 (3216 Metric) 10 pF 0.031' (0.79mm) Built in Capacitor 40 Ohms Ceramic 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount -20°C ~ 80°C 10 MHz
CSTCE10M0G52Z-R0 CSTCE10M0G52Z-R0 Murata Electronics CERAMIC RES 10.0000MHZ 10PF SMD Dalam stok807700 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.2% 3-SMD, Non-Standard 10 pF 0.031" (0.79mm) Built in Capacitor 40 Ohms Ceramic 0.126" L x 0.051" W (3.20mm x 1.30mm) Surface Mount -40°C ~ 125°C 10 MHz
CSTCE12M0G55A-R0 CSTCE12M0G55A-R0 Murata Electronics CERAMIC RES 12.0000MHZ 33PF SMD Dalam stok78500 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.2% 3-SMD, Non-Standard 33 pF 0.031" (0.79mm) Built in Capacitor 30 Ohms Ceramic 0.126" L x 0.051" W (3.20mm x 1.30mm) Surface Mount -40°C ~ 125°C 12 MHz
CSTCE10M0G52A-R0 CSTCE10M0G52A-R0 Murata Electronics CERAMIC RES 10.0000MHZ 10PF SMD Dalam stok809300 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.2% 3-SMD, Non-Standard 10 pF 0.031' (0.79mm) Built in Capacitor - Ceramic 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount -40°C ~ 125°C 10 MHz
CSTLS8M00G53-A0 CSTLS8M00G53-A0 Murata Electronics CERAMIC RES 8.0000MHZ 15PF T/H Dalam stok440300 pcs Cut Tape (CT) CSTLS CERALOCK® CSTLS ±0.5% ±0.2% Radial - 3 Lead, 2.50mm Pitch 15 pF 0.236' (6.00mm) Built in Capacitor 25 Ohms Ceramic 0.315' L x 0.118' W (8.00mm x 3.00mm) Through Hole -20°C ~ 80°C 8 MHz
RO3101A-11 RO3101A-11 RFMi RESONATOR,SM,433.920 MHZ Dalam stok97550 pcs Tape & Reel (TR) RO3101 - ±75kHz 32ppb 4-SMD, No Lead - 0.063" (1.60mm) - - SAW 0.197" L x 0.138" W (5.00mm x 3.50mm) Surface Mount -40°C ~ 85°C 433.92 MHz
CSTCR4M91G55-R0 CSTCR4M91G55-R0 Murata Electronics CERAMIC RES 4.9100MHZ 39PF SMD Dalam stok268540 pcs Tape & Reel (TR) CSTCR CERALOCK® CSTCR ±0.5% ±0.1% 3-SMD, Non-Standard 39 pF 0.047' (1.20mm) Built in Capacitor 60 Ohms Ceramic 0.177' L x 0.079' W (4.50mm x 2.00mm) Surface Mount -20°C ~ 80°C 4.91 MHz
CSTCR4M19G55-R0 CSTCR4M19G55-R0 Murata Electronics CER RESONATOR Dalam stok190250 pcs Tape & Reel (TR) CSTCR CERALOCK® CSTCR ±0.5% ±0.2% 3-SMD, Non-Standard 39 pF 0.047' (1.20mm) Built in Capacitor 60 Ohms Ceramic 0.177' L x 0.079' W (4.50mm x 2.00mm) Surface Mount -20°C ~ 80°C 4.194 MHz
CCR10.0MXC8T CCR10.0MXC8T TDK Corporation CERAMIC RES 10.0000MHZ 18PF SMD Dalam stok522900 pcs Tape & Reel (TR) - CCR-MXC8 ±0.5% ±0.3% 3-SMD, Non-Standard 18 pF 0.031" (0.79mm) Built in Capacitor 40 Ohms Ceramic 0.126" L x 0.049" W (3.20mm x 1.25mm) Surface Mount -40°C ~ 85°C 10 MHz
CSBLA1M02J58-B0 CSBLA1M02J58-B0 Murata Electronics CER RESONATOR T/H Dalam stok81430 pcs Bulk CSBLA * - - Radial, Box - 2 Lead, 2.50mm Pitch - 0.366" (9.30mm) - - - 0.276" L x 0.138" W (7.00mm x 3.50mm) Through Hole - -
RO3103A RO3103A RFMi RESONATOR,SM,418.000 MHZ Dalam stok44620 pcs Tape & Reel (TR) RO3103 - ±75kHz 32ppb 4-SMD, No Lead - 0.063" (1.60mm) - - SAW 0.197" L x 0.138" W (5.00mm x 3.50mm) Surface Mount -40°C ~ 125°C 418 MHz
CSTCE12M2G55-R0 CSTCE12M2G55-R0 Murata Electronics CER RESONATOR SMD Dalam stok801500 pcs Tape & Reel (TR) CSTCE * - - 3-SMD, Non-Standard - 0.031' (0.79mm) - - - 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount - -
CSTCR4M00G55A-R0 CSTCR4M00G55A-R0 Murata Electronics CER RESONATOR SMD Dalam stok324500 pcs Tape & Reel (TR) CSTCR * - - 3-SMD, Non-Standard - 0.047' (1.19mm) - - - 0.177' L x 0.079' W (4.50mm x 2.00mm) Surface Mount - -
RO3132A RO3132A Murata Electronics SAW RES 312.0000MHZ SMD Dalam stok586900 pcs Tape & Reel (TR) RO31 - ±10ppm ±0.032ppm 4-SMD, No Lead - 0.060" (1.53mm) - 1 MOhms SAW 0.197" L x 0.138" W (5.00mm x 3.50mm) Surface Mount -40°C ~ 85°C 312 MHz
CSTLS10M0G53-B0 CSTLS10M0G53-B0 Murata Electronics CERAMIC RES 10.0000MHZ 15PF T/H Dalam stok345050 pcs Bulk CSTLS CERALOCK® CSTLS ±0.5% ±0.2% Radial - 3 Lead, 2.50mm Pitch 15 pF 0.236' (6.00mm) Built in Capacitor 25 Ohms Ceramic 0.315' L x 0.118' W (8.00mm x 3.00mm) Through Hole -20°C ~ 80°C 10 MHz
CSTCW33M3X51-R0 CSTCW33M3X51-R0 Murata Electronics CER RESONATOR Dalam stok886000 pcs Tape & Reel (TR) CSTCW * - - 3-SMD, Non-Standard - 0.053' (1.34mm) - - - 0.098' L x 0.079' W (2.50mm x 2.00mm) - - -
CSTCC3M64G53-R0 CSTCC3M64G53-R0 Murata Electronics CER RESONATOR SMD Dalam stok116500 pcs Bulk CSTCC * - - 3-SMD, Non-Standard - 0.061' (1.55mm) - - - 0.283' L x 0.118' W (7.20mm x 3.00mm) Surface Mount - -
PBRC5.00HR50X000 PBRC5.00HR50X000 KYOCERA AVX CERAMIC RES 5.0000MHZ 30PF SMD Dalam stok794600 pcs Tape & Reel (TR) - PBRC-H, Kyocera ±0.5% ±0.5% 3-SMD, Non-Standard 30 pF 0.079" (2.00mm) Built in Capacitor - Ceramic 0.291" L x 0.134" W (7.40mm x 3.40mm) Surface Mount -40°C ~ 85°C 5 MHz
PBRC5.00GR50X000 PBRC5.00GR50X000 KYOCERA AVX CERAMIC RES 5.0000MHZ SMD Dalam stok352100 pcs Tape & Reel (TR) - PBRC-G, Kyocera ±0.5% ±0.5% 2-SMD, Non-Standard - 0.079' (2.00mm) - - Ceramic 0.291' L x 0.134' W (7.40mm x 3.40mm) Surface Mount -40°C ~ 85°C 5 MHz
CSTCR4M00G55Z-R0 CSTCR4M00G55Z-R0 Murata Electronics CERAMIC RES 4.0000MHZ 39PF SMD Dalam stok192050 pcs Tape & Reel (TR) CSTCR CERALOCK® CSTCR ±0.5% ±0.2% 3-SMD, Non-Standard 39 pF 0.047" (1.19mm) Built in Capacitor - Ceramic 0.177" L x 0.079" W (4.50mm x 2.00mm) Surface Mount -40°C ~ 125°C 4 MHz
CCR33.86MXC7T CCR33.86MXC7T TDK Corporation CERAMIC RES 33.8600MHZ 8PF SMD Dalam stok134390 pcs Tape & Reel (TR) - CCR ±0.5% ±0.2% 3-SMD, Non-Standard 8 pF 0.039' (1.00mm) Built in Capacitor 40 Ohms Ceramic 0.098' L x 0.079' W (2.50mm x 2.00mm) Surface Mount -40°C ~ 85°C 33.86 MHz
CSTCE16M6V53-R0 CSTCE16M6V53-R0 Murata Electronics CER RESONATOR SMD Dalam stok700000 pcs Tape & Reel (TR) CSTCE * - - 3-SMD, Non-Standard - 0.031" (0.79mm) - - - 0.126" L x 0.051" W (3.20mm x 1.30mm) Surface Mount - -
CSTCR4M91G55A-R0 CSTCR4M91G55A-R0 Murata Electronics CER RESONATOR SMD Dalam stok242200 pcs Tape & Reel (TR) CSTCR * - - 3-SMD, Non-Standard - 0.047' (1.19mm) - - - 0.177' L x 0.079' W (4.50mm x 2.00mm) Surface Mount - -
PBRV4.00MR10Y000 PBRV4.00MR10Y000 KYOCERA AVX CERAMIC RES 4.0000MHZ 15PF SMD Dalam stok103200 pcs Tape & Reel (TR) - PBRV-M, Kyocera ±0.1% ±0.3% 3-SMD, Non-Standard 15 pF 0.047" (1.19mm) Built in Capacitor - Ceramic 0.177" L x 0.079" W (4.50mm x 2.00mm) Surface Mount -40°C ~ 125°C 4 MHz
CSTCW27M0X51-R0 CSTCW27M0X51-R0 Murata Electronics CER RESONATOR Dalam stok633800 pcs Tape & Reel (TR) CSTCW * - - 3-SMD, Non-Standard - 0.053' (1.34mm) - - - 0.098' L x 0.079' W (2.50mm x 2.00mm) - - -
CSTCR6M29G53-R0 CSTCR6M29G53-R0 Murata Electronics CER RESONATOR Dalam stok243440 pcs Tape & Reel (TR) CSTCR CERALOCK® CSTCR ±0.5% ±0.2% 3-SMD, Non-Standard 15 pF 0.047' (1.20mm) Built in Capacitor 50 Ohms Ceramic 0.177' L x 0.079' W (4.50mm x 2.00mm) Surface Mount -20°C ~ 80°C 6.29 MHz
CSTCE14M0V51-R0 CSTCE14M0V51-R0 Murata Electronics CER RESONATOR SMD Dalam stok148100 pcs Tape & Reel (TR) CSTCE * - - 3-SMD, Non-Standard - 0.031' (0.79mm) - - - 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount - -
CCR8.0MXC8T CCR8.0MXC8T TDK Corporation CERAMIC RES 8.0000MHZ 18PF SMD Dalam stok511500 pcs Tape & Reel (TR) - CCR-MXC8 ±0.5% ±0.3% 3-SMD, Non-Standard 18 pF 0.031" (0.79mm) Built in Capacitor 40 Ohms Ceramic 0.126" L x 0.049" W (3.20mm x 1.25mm) Surface Mount -40°C ~ 85°C 8 MHz
CSTCE16M0V53C-R0 CSTCE16M0V53C-R0 Murata Electronics CERAMIC RES 16.0000MHZ 15PF SMD Dalam stok98200 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.15% 3-SMD, Non-Standard 15 pF 0.031' (0.79mm) Built in Capacitor - Ceramic 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount -40°C ~ 125°C 16 MHz
ECS-SR1-3.58-B-TR ECS-SR1-3.58-B-TR ECS Inc. CERAMIC RES 3.5800MHZ 30PF SMD Dalam stok95780 pcs Tape & Reel (TR) - ECS-SR1-B ±0.5% ±0.3% 3-SMD, Non-Standard 30 pF 0.087' (2.20mm) Built in Capacitor - Ceramic 0.295' L x 0.130' W (7.50mm x 3.30mm) Surface Mount -20°C ~ 80°C 3.58 MHz
RO3144E RO3144E RFMi RESONATOR,SM,916.500 MHZ Dalam stok67280 pcs Tape & Reel (TR) RO3144 - ±200kHz 32ppb 6-SMD, No Lead - 0.054" (1.38mm) - - SAW 0.118" L x 0.118" W (3.00mm x 3.00mm) Surface Mount -40°C ~ 125°C 916.5 MHz
CSTCE10M0G55-R0 CSTCE10M0G55-R0 Murata Electronics CERAMIC RES 10.0000MHZ 33PF SMD Dalam stok450500 pcs Tape & Reel (TR) CSTCE CERALOCK® CSTCE ±0.5% ±0.2% 3-SMD, Non-Standard 33 pF 0.031" (0.79mm) Built in Capacitor - Ceramic 0.126" L x 0.051" W (3.20mm x 1.30mm) Surface Mount -20°C ~ 80°C 10 MHz
CSTCW50M0X51-R0 CSTCW50M0X51-R0 Murata Electronics CER RESONATOR Dalam stok301700 pcs Tape & Reel (TR) CSTCW * - - 3-SMD, Non-Standard - 0.053' (1.34mm) - - - 0.098' L x 0.079' W (2.50mm x 2.00mm) - - -
CSTCE8M19G55-R0 CSTCE8M19G55-R0 Murata Electronics CER RESONATOR SMD Dalam stok527200 pcs Tape & Reel (TR) CSTCE * - - 3-SMD, Non-Standard - 0.031' (0.79mm) - - - 0.126' L x 0.051' W (3.20mm x 1.30mm) Surface Mount - -
CSTCR4M00G15C99-R0 CSTCR4M00G15C99-R0 Murata Electronics CERAMIC RES 4.0000MHZ 39PF SMD Dalam stok197100 pcs Tape & Reel (TR) CSTCR CERALOCK® CSTCR ±0.1% ±0.13% 3-SMD, Non-Standard 39 pF 0.047" (1.19mm) Built in Capacitor - Ceramic 0.177" L x 0.079" W (4.50mm x 2.00mm) Surface Mount -40°C ~ 125°C 4 MHz
1234
0 RFQ
Bakul membeli belah (0 Items)
Ia kosong.
Bandingkan senarai (0 Items)
Ia kosong.
Maklum balas

Maklum balas anda penting!Di Allelco, kami menghargai pengalaman pengguna dan berusaha untuk memperbaikinya secara berterusan.
Sila kongsi komen anda dengan kami melalui borang maklum balas kami, dan kami akan bertindak balas dengan segera.
Terima kasih kerana memilih Allelco.

Subjek
E-mel
Komen
Captcha
Seret atau klik untuk memuat naik fail
Muat naik fail
Jenis: .xls, .xlsx, .doc, .docx, .jpg, .png dan .pdf.
Max Saiz Fail: 10MB