Sobre Nós Contacte-nos Enviar BOM
Inquérito(0)
Português
Fechar Menu
Ver tudo

Por favor, use a versão em inglês como a versão oficialRetornar

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) Japan(日本語) Korea(한국의) Thailand(ภาษาไทย) Malaysia(Melayu) Singapore(Melayu) Vietnam(Tiếng Việt) Philippines(Pilipino) United Arab Emirates(العربية) Iran(فارسی) Tajikistan(فارسی) India(हिंदी) Madagascar(malaɡasʲ) New Zealand(Maori) Brazil(Português) Angola(Português) Mozambique(Português) United States(English) Canada(English) Haiti(Ayiti) Mexico(español)
CasaProdutosCircuitos integrados (ICs)MPCI - carregadores de bateria

MPCI - carregadores de bateria

Produtos 1,625 encontrados

Lista de Produtos

1234567...33
Comparar Imagem Papel # Fabricante Descrição Inventário Modelo ECAD RoHS Embalagem do dispositivo fornecedor Proteção contra Falhas Corrente - Carregamento Funções programáveis Voltagem da bateria Alimentação de tensão (máx.) Número do produto base Pacote Série Temperatura de operação Tipo de montagem Química da bateria Número de células Corrente de carga - Max Interface Caixa / Gabinete Quantidade
BQ2054SN BQ2054SN Texas Instruments IC BATT FAST CHG LI-ION 16SOIC Disponível3033 pcs 16-SOIC Over Current, Over Voltage Constant - - 5.5V BQ2054 Tube - -20°C ~ 70°C (TA) Surface Mount Lithium Ion - - - 16-SOIC (0.154', 3.90mm Width)
BQ2000SN-B5G4 BQ2000SN-B5G4 Texas Instruments IC BAT CHG MULT-CHEM 1-4CL 8SOIC Disponível6750 pcs 8-SOIC - Constant - Programmable Current, Timer, Voltage - 6V BQ2000 Tube - -20°C ~ 70°C (TA) Surface Mount Multi-Chemistry 1 ~ 4 - - 8-SOIC (0.154', 3.90mm Width)
MAX17006BETP+T MAX17006BETP+T Analog Devices Inc./Maxim Integrated IC BAT CHG MULTCHEM 2-3CL 20TQFN Disponível5429 pcs 20-TQFN (4x4) Over Current, Short Circuit Constant - Programmable - 12.6V 26V MAX17006 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Multi-Chemistry 2 ~ 3 5A - 20-WFQFN Exposed Pad
BQ25898YFFT BQ25898YFFT Texas Instruments IC BATT CHG LI-ION 1CELL 42DSBGA Disponível10515 pcs 42-DSBGA (2.8x2.5) Over Current, Over Temperature - - - 14V BQ25898 Tape & Reel (TR) MaxCharge™ -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 4A I²C, USB 42-UFBGA, DSBGA
ISL95538BHRTZ ISL95538BHRTZ Renesas Electronics America Inc IC BATT CHG LI-ION 1-4CEL 32TQFN Disponível8438 pcs 32-TQFN (4x4) - - - 18.3V (Max) 23.4V ISL95538 Tube R3™ - Surface Mount Lithium Ion 1 ~ 4 - I²C, SMBus 32-WFQFN Exposed Pad
BQ25616RTWT BQ25616RTWT Texas Instruments IC BATT CHG LI-ION 1CELL 24WQFN Disponível10439 pcs 24-WQFN (4x4) Over Current, Over Voltage Constant - Programmable Current 4.35V 13.5V BQ25616 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 3A USB 24-WFQFN Exposed Pad
BQ24250CYFFR BQ24250CYFFR Texas Instruments IC BATT CHG LI-ION 1CELL 30DSBGA Disponível14721 pcs 30-DSBGA Over Temperature, Over Voltage Constant - Programmable Current 4.2V 10.5V BQ24250 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion 1 2A I²C 30-UFBGA, DSBGA
MAX2003CWE MAX2003CWE Analog Devices Inc./Maxim Integrated IC BATT FAST CHG NICD/NIMH Disponível34580 pcs 16-SOIC Over Temperature Constant - Programmable Current, Timer, Voltage - 5.5V MAX2003 Bulk - 0°C ~ 70°C (TA) Surface Mount Multi-Chemistry 1 - - 16-SOIC (0.295", 7.50mm Width)
LTC4001EUF#PBF LTC4001EUF#PBF Analog Devices Inc. IC BATT CHG LI-ION 1CELL 16QFN Disponível7299 pcs 16-QFN (4x4) Over Voltage, Short Circuit Constant - Programmable Current, Timer 4.2V 5.5V LTC4001 Tube - -40°C ~ 85°C (TA) Surface Mount Lithium Ion 1 2A - 16-WQFN Exposed Pad
BQ25171QWDRCRQ1 BQ25171QWDRCRQ1 Texas Instruments AUTOMOTIVE, 800-MA LINEAR BATTER Disponível31930 pcs 10-VSON (3x3) Over Current, Over Temperature, Over Voltage, Short Circuit Constant - Programmable Current, Timer 10.5V (Max) 18V BQ25171 Tape & Reel (TR) Automotive, AEC-Q100 -40°C ~ 125°C (TJ) Surface Mount, Wettable Flank Lithium Ion/Polymer 1 ~ 6 800mA - 10-VFDFN Exposed Pad
BQ24113ARHLT BQ24113ARHLT Texas Instruments IC BATT CHG LI-ION 1-2CEL 20VQFN Disponível10265 pcs 20-VQFN (3.5x4.5) Over Temperature, Over Voltage Constant - Programmable Current, Timer 8.4V 16V BQ24113 Tape & Reel (TR) bqSWITCHER™ -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 ~ 2 2A - 20-VFQFN Exposed Pad
BQ24120RHLRG4 BQ24120RHLRG4 Texas Instruments IC BATT CHG LI-ION 1CELL 20VQFN Disponível4570 pcs 20-VQFN (3.5x4.5) Over Temperature Constant - Programmable Current, Timer 4.2V 16V BQ24120 Tape & Reel (TR) bqSWITCHER™ -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 2A - 20-VFQFN Exposed Pad
BQ24038RHLT BQ24038RHLT Texas Instruments IC BATT CHG LI-ION 1CELL 20VQFN Disponível10408 pcs 20-VQFN (3.5x4.5) Over Temperature, Reverse Current, Short Circuit Constant - Programmable Current, Timer 4.36V 16V BQ24038 Tape & Reel (TR) bqTINY™ III -40°C ~ 125°C (TJ) Surface Mount Lithium Ion/Polymer 1 1.5A USB 20-VFQFN Exposed Pad
MP2606DQ-LF-Z MP2606DQ-LF-Z Monolithic Power Systems Inc. IC BATT CHG LI-ION 1CELL 10QFN Disponível24982 pcs 10-QFN (3x3) Over Current, Over Voltage Constant - Programmable Current 4.2V 6.5V MP2606 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion 1 1A USB 10-VFDFN Exposed Pad
BQ24721CRHBT BQ24721CRHBT Texas Instruments IC BAT CHG MULTCHEM 3-4CL 32VQFN Disponível3193 pcs 32-VQFN (5x5) Over Current - Current 19.2V (Max) 24V BQ24721 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Multi-Chemistry 3 ~ 4 - I²C 32-VFQFN Exposed Pad
MC34673AEPR2 MC34673AEPR2 Freescale Semiconductor IC BATT CHG LI-ION 1CELL 8UDFN Disponível38812 pcs 8-UDFN (3x2) Over Voltage Constant - Programmable - 4.2V 6.6V MC34673 Bulk - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 1.2A - 8-UFDFN Exposed Pad
LTC1733EMSE#PBF LTC1733EMSE#PBF Analog Devices Inc. IC BATT CHG LI-ION 1CELL 10MSOP Disponível14436 pcs 10-MSOP-EP Over Temperature Constant - Programmable Timer 4.2V 6.5V LTC1733 Tube - -40°C ~ 85°C (TA) Surface Mount Lithium Ion 1 1.5A - 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
ISL9201IRZ ISL9201IRZ Renesas Electronics America Inc IC BATT CHG LI-ION 1CELL 10DFN Disponível8290 pcs 10-DFN (3x3) Over Temperature Constant - Programmable Timer 4.2V 6.5V ISL9201 Tube - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 900mA - 10-VFDFN Exposed Pad
ISL88732HRTZ-T ISL88732HRTZ-T Renesas Electronics America Inc IC BATT CHG LI-ION 1-4CELL 28QFN Disponível11776 pcs 28-QFN (5x5) Over Current, Over Temperature - - - 22V ISL88732 Tape & Reel (TR) - - Surface Mount Lithium Ion 1 ~ 4 8A I²C 28-WFQFN Exposed Pad
MCP73833-CNI/UN MCP73833-CNI/UN Microchip Technology IC BATT CNTRL LI-ION 1CEL 10MSOP Disponível36679 pcs 10-MSOP Over Temperature Constant - Programmable Current 4.2V 6V MCP73833 Tube - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 1.1A - 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
BQ24745RHDTG4 BQ24745RHDTG4 Texas Instruments IC BAT CHG MULTCHEM 2-4CL 28VQFN Disponível12270 pcs 28-VQFN (5x5) Over Voltage Constant - Programmable - 19.2V (Max) 24V BQ24745 Tape & Reel (TR) - -40°C ~ 125°C (TJ) Surface Mount Multi-Chemistry 2 ~ 4 8.064A I²C 28-VFQFN Exposed Pad
BQ2057CDGK BQ2057CDGK Texas Instruments IC BATT CHG LI-ION 1CELL 8VSSOP Disponível10317 pcs 8-VSSOP - Constant - Programmable Current 4.2V 15V BQ2057 Tube - -20°C ~ 70°C (TA) Surface Mount Lithium Ion/Polymer 1 - - 8-TSSOP, 8-MSOP (0.118', 3.00mm Width)
BQ24041DSQT BQ24041DSQT Texas Instruments IC BATT CHG LI-ION 1CELL 10SON Disponível33921 pcs 10-WSON (2x2) Over Temperature, Over Voltage, Short Circuit Constant - Programmable - 4.2V 28V BQ24041 Tape & Reel (TR) - 0°C ~ 125°C (TJ) Surface Mount Lithium Ion/Polymer 1 1A - 10-WFDFN Exposed Pad
ISL9200IRZ ISL9200IRZ Renesas Electronics America Inc IC BATT CHG LI-ION 12DFN Disponível13310 pcs 12-DFN (4x3) Over Current, Over Temperature, Over Voltage - - - 6.5V ISL9200 Tube - -40°C ~ 85°C (TA) Surface Mount Lithium Ion - - - 12-VFDFN Exposed Pad
LTC1731EMS8-4.2#TRPBF LTC1731EMS8-4.2#TRPBF Analog Devices Inc. IC BATT CHG MULT-CHEM 1CEL 8MSOP Disponível8767 pcs 8-MSOP - Constant - Programmable Timer 4.2V 12V LTC1731 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Multi-Chemistry 1 500mA - 8-TSSOP, 8-MSOP (0.118', 3.00mm Width)
SC811ULTRT SC811ULTRT Semtech Corporation IC BATT CHG LI-ION 1CELL 8MLPD Disponível57510 pcs 8-MLPD-UT (2x2) Over Current, Over Temperature, Over Voltage, Short Circuit Constant - Programmable Current 4.2V 8.2V SC811 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion 1 1A USB 8-UFDFN Exposed Pad
LT3650IDD-8.4#TRPBF LT3650IDD-8.4#TRPBF Analog Devices Inc. IC BATT CHG LI-ION 2CELL 12DFN Disponível5710 pcs 12-DFN (3x3) Over Temperature Constant - Programmable Timer 8.4V 32V LT3650 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 2 2A - 12-WFDFN Exposed Pad
LTC4071EMS8E#PBF LTC4071EMS8E#PBF Analog Devices Inc. IC BATT CHG LI-ION 8MSOP Disponível11070 pcs 8-MSOP-EP - - - 4.2V - LTC4071 Tube - -40°C ~ 125°C (TJ) Surface Mount Lithium Ion/Polymer - - - 8-TSSOP, 8-MSOP (0.118', 3.00mm Width) Exposed Pad
MAX8856ETD+T MAX8856ETD+T Analog Devices Inc./Maxim Integrated IC BATT CHG LI-ION 1CELL 14TDFN Disponível8215 pcs 14-TDFN (3x3) Over Voltage Constant - Programmable - 4.2V 5.5V MAX8856 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion 1 1A USB 14-WFDFN Exposed Pad
BQ24298RTWR BQ24298RTWR Texas Instruments IC BATT CHG LI-ION 1CELL 24WQFN Disponível20705 pcs 24-WQFN (4x4) Over Current, Over Temperature, Over Voltage Constant - Programmable - 4.2V 6.2V BQ24298 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 3A I²C 24-WFQFN Exposed Pad
ISL88731AHRZ-T ISL88731AHRZ-T Renesas Electronics America Inc IC BATT CHG LI-ION 1-4CEL 28TQFN Disponível14266 pcs 28-QFN (5x5) Short Circuit Constant, Pulsed - 16.8V 26V ISL88731 Tape & Reel (TR) - -10°C ~ 100°C (TA) Surface Mount Lithium Ion 1 ~ 4 8A I²C 28-WFQFN Exposed Pad
BQ2057DGKRG4 BQ2057DGKRG4 Texas Instruments IC BATT CHG LI-ION 1CELL 8VSSOP Disponível14650 pcs 8-VSSOP - Constant - Programmable Current 4.1V 15V BQ2057 Tape & Reel (TR) - -20°C ~ 70°C (TA) Surface Mount Lithium Ion/Polymer 1 - - 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
ISL6257HRZ ISL6257HRZ Renesas Electronics America Inc IC BATT CHG LI-ION 2-4CELL 28QFN Disponível8050 pcs 28-QFN (5x5) Over Temperature, Short Circuit Constant - Programmable - 17.64V (Max) 25V ISL6257 Tube - -10°C ~ 100°C (TA) Surface Mount Lithium Ion/Polymer 2 ~ 4 - - 28-VFQFN Exposed Pad
MP2617AGL-Z MP2617AGL-Z Monolithic Power Systems Inc. IC BATT CHG LI-ION 1CELL 20QFN Disponível27763 pcs 20-QFN (3x4) Over Temperature Constant - Programmable Timer 4.35V 10V MP2617 Tape & Reel (TR) - -40°C ~ 125°C (TJ) Surface Mount Lithium Ion 1 - USB 20-PowerTFQFN
LM3420M5X-12.6 LM3420M5X-12.6 Texas Instruments IC BATT CHG LI-ION 3CELL SOT23-5 Disponível14370 pcs SOT-23-5 - - - 12.6V 20V LM3420 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion 3 - - SC-74A, SOT-753
LTC1732EMS-8.4#PBF LTC1732EMS-8.4#PBF Analog Devices Inc. IC BAT CHG MULT-CHEM 2CEL 10MSOP Disponível12421 pcs 10-MSOP - Constant - Programmable Timer 8.4V 12V LTC1732 Tube - -40°C ~ 85°C (TA) Surface Mount Multi-Chemistry 2 585mA - 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
ISL6292-2CR4 ISL6292-2CR4 Renesas Electronics America Inc IC BATT CHG LI-ION 1CELL 16QFN Disponível7920 pcs 16-QFN (4x4) - Constant - Programmable - 4.2V 6.5V ISL6292 Tube - -20°C ~ 70°C (TA) Surface Mount Lithium Ion/Polymer 1 2A USB 16-VQFN Exposed Pad
LX2206ILD LX2206ILD Microsemi Corporation IC BATT CHG LI-ION 1CELL 10MLPD Disponível12670 pcs 10-MLPD (3x3) Reverse Current Constant - Programmable Current 4.2V 6V LX2206 Tube - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 1A USB 10-TFDFN Exposed Pad
MCP73871-1AAI/ML MCP73871-1AAI/ML Microchip Technology IC BATT CHG LI-ION 1CELL 20QFN Disponível22440 pcs 20-QFN (4x4) Over Temperature Constant - Programmable Timer 4.1V 6V MCP73871 Tube - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 1.1A USB 20-VFQFN Exposed Pad
BQ24161BRGER BQ24161BRGER Texas Instruments IC BATT CHG LI-ION 1CELL 24VQFN Disponível12568 pcs 24-VQFN (4x4) Over Temperature, Over Voltage Constant - Programmable - 3.7V 10V BQ24161 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 2.5A I²C 24-VFQFN Exposed Pad
ISL6292-2CR4Z-T ISL6292-2CR4Z-T Renesas Electronics America Inc IC BATT CHG LI-ION 1CELL 16QFN Disponível31373 pcs 16-QFN (4x4) - Constant - Programmable - 4.2V 6.5V ISL6292 Tape & Reel (TR) - -20°C ~ 70°C (TA) Surface Mount Lithium Ion/Polymer 1 2A USB 16-VQFN Exposed Pad
NCP1800DM42R2 NCP1800DM42R2 onsemi IC BATT CHG LI-ION 1CELL 8MICRO Disponível15460 pcs 8-MSOP Over Voltage Constant - Programmable Current 4.2V 16V NCP1800 Tape & Reel (TR) - -20°C ~ 85°C (TA) Surface Mount Lithium Ion 1 1A - 8-TSSOP, 8-MSOP (0.118', 3.00mm Width)
MP2603EJ-LF-P MP2603EJ-LF-P Monolithic Power Systems Inc. IC BATT CHG LI-ION 1CEL TSOT23-5 Disponível35858 pcs TSOT-23-5 Over Current, Over Temperature Constant - Programmable - 4.2V 5.25V MP2603 Tape & Reel (TR) - -20°C ~ 85°C (TA) Surface Mount Lithium Ion 1 150mA - SOT-23-5 Thin, TSOT-23-5
DS2710G+ DS2710G+ Analog Devices Inc./Maxim Integrated IC BATT CHG NIMH 1CELL 10TDFN Disponível9757 pcs 10-TDFN (3x4) - - Timer - 5.5V DS2710 Tube - -20°C ~ 70°C (TA) Surface Mount Nickel Metal Hydride 1 - - 10-WFDFN Exposed Pad
BQ2004PN BQ2004PN Texas Instruments IC BATT CONTRL MULTI-CHEM 16DIP Disponível2450 pcs 16-PDIP - Constant, Pulsed Voltage - 5.5V BQ2004 Tube - -20°C ~ 70°C (TA) Through Hole Multi-Chemistry - - - 16-DIP (0.300', 7.62mm)
MCP73828-4.2VUA MCP73828-4.2VUA Microchip Technology IC BATT CONTRL LI-ION 1CEL 8MSOP Disponível32708 pcs 8-MSOP - Constant - Programmable - 4.2V 5.5V MCP73828 Tube - -20°C ~ 85°C (TA) Surface Mount Lithium Ion 1 - - 8-TSSOP, 8-MSOP (0.118', 3.00mm Width)
LT3651EUHE-8.4#PBF LT3651EUHE-8.4#PBF Analog Devices Inc. IC BATT CHG LI-ION 2CELL 36QFN Disponível5854 pcs 36-QFN (5x6) Over Temperature Constant - Programmable Current, Timer 8.4V 32V LT3651 Tube - -40°C ~ 125°C (TJ) Surface Mount Lithium Ion/Polymer 2 4A - 36-WFQFN Exposed Pad
MCP73844T-840I/MS MCP73844T-840I/MS Microchip Technology IC BATT CNTL LI-ION 1-2CEL 8MSOP Disponível29174 pcs 8-MSOP - - Timer 8.4V 12V MCP73844 Tape & Reel (TR) - -40°C ~ 85°C (TA) Surface Mount Lithium Ion/Polymer 1 ~ 2 - - 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
BQ24105RHLR BQ24105RHLR Texas Instruments IC BAT CHG MULTCHEM 1-3CL 20VQFN Disponível10152 pcs 20-VQFN (3.5x4.5) Over Temperature, Over Voltage Constant - Programmable Current, Timer 15.5V 16V BQ24105 Tape & Reel (TR) bqSWITCHER™ -40°C ~ 85°C (TA) Surface Mount Multi-Chemistry 1 ~ 3 2A - 20-VFQFN Exposed Pad
ISL95521AHRZ ISL95521AHRZ Renesas Electronics America Inc IC BATT CHG LI-ION 2-4CELL 32QFN Disponível9206 pcs 32-QFN (4x4) Over Current, Over Temperature - - - 25V ISL95521 Tube - - Surface Mount Lithium Ion/Polymer 2 ~ 4 - SMBus 32-VFQFN Exposed Pad
1234567...33
Allelco
Sobre nós
História
Certificações
Recrutamento
Políticos
Termo e Condição
Política de Privacidade
Política de Cookies
Serviços
Rastreamento de pedidos
Reembolso e Devolução
Perguntas frequentes
Contacte-nos
Ordem
Envio e entrega
Métodos de pagamento
Minha Conta
The BlogsHot PartsChange LanguageNewsSite map
Contacte-nos
Endereço da sede:
Sala C 13/F Harvard Commercial Building
105-111 Thomson Road Wan Chai
Hong Kong
Serviço Tel: +852-91464856
E -mail de serviço: info@allelco.com
SEGUE-NOS
Copyright © 2012-2023 AllelcoElec.com.Todos os direitos reservados.
0 RFQ
Carrinho de compras (0 Items)
Ele está vazio.
Enviar consulta
Lista de comparação (0 Items)
Ele está vazio.
Opinião

Seu feedback é importante!Na Allelco, valorizamos a experiência do usuário e nos esforçamos para melhorá -la constantemente.
Compartilhe seus comentários conosco através do nosso formulário de feedback e responderemos prontamente.
Obrigado por escolher Allelco.

Assunto
O email
Observações
Código de Verificação
Arraste ou clique para fazer upload de arquivo
Subir arquivo
TIPOS: .xls, .xlsx, .doc, .docx, .jpg, .png e .pdf.
Max Tamanho do arquivo: 10 MB