THE SMD CODEBOOK SMD Codes. SMD devices are, by their very nature, too small to carry conventional semiconductor type numbers. Instead, a somewhat arbitrary coding system has grown up, where the device package carries a simple two- or three-character ID code. BB639E7904HTSA1, Varicap Diodes / Varactor Diodes, Infineon Variable Capacitance Diodes, commonly known as Varicap, Varactor or Tuning diodes, are useful in many applications where a change in capacitance derived from a change in voltage is required. Compre Diodos de Capacitancia Variable (Varicaps, Varactors). Farnell ofrece cotizaciones rápidas, despacho el mismo día, entregas rápidas, amplio inventario, hojas técnicas y soporte técnico.