BB 639 is a variable capacitance diode from Dinghao. It is mainly used for tuning the extended frequency bands of VHF TV/VTR tuners.
This datasheet describes the Siemens BB 639 silicon variable capacitance diode, intended for tuning extended VHF TV/VTR frequency bands. It includes the part number, ordering code, and package type (SOD‑323).
Key electrical parameters are provided, such as reverse voltage, forward current, temperature ranges, and thermal resistance, together with detailed DC characteristics like reverse current and capacitance values at specified bias voltages and frequencies.
| Reverse voltage (Va) | 30 V |
|---|---|
| Reverse voltage (R > 5 kΩ) | 35 V |
| Forward current (I) | 20 mA |
| Operating temperature range | -55 °C … +150 °C |
| Junction‑ambient thermal resistance (Rusa) | < 450 K/W |
The diode can withstand up to 30 V reverse voltage, or 35 V when the series resistance exceeds 5 kΩ.
The forward current rating is 20 mA.
It operates from –55 °C up to +150 °C.