LESHAN RADIO COMPANY, LTD. UHF variable capacitance diode BB 149 DESCRIPTION The BB149 is a variable capacitance diode, fabricated in planar technology, and encapsulated in the SOD323 very small plastic SMD package. The excellent matching performance is achieved by gliding matching and a direct matching assembly procedure. The unmatched type, BB159 has the same specification. 1 CATHODE 1 2 SOD– 323 MARKING CODE:P9 2 ANODE P9 FEATURES · Excellent linearity · Excellent matching to 1% DMA · Very small plastic SMD package · C28: 2.1 pF; ratio 9 · Low series resistance. APPLICATIONS · Electronic tuning in UHF television tuners · VCO. 1 LIMITING VALUES In accordance with the Absolute Maximum Rating System (IEC 134). SYMBOL PARAMETER MIN. MAX. VR continuous reverse voltage – 30 IF continuous forward current – 20 Tstg storage temperature –55 +150 Tj operating junction temperature –55 +125 2 UNIT V mA °C °C ELECTRICAL CHARACTERISTICS Tj = 25 °C unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT IR reverse current V R = 30 V; see Fig.2 VR = 30 V; Tj = 85 °C; see Fig.2 – – 10 200 nA nA rs Cd diode series resistance diode capacitance f = 470 MHz; note 1 VR = 0.5 V; f = 1 MHz; see Figs 1 and 3 – 18 0.75 19.5 Ω pF VR = 28 V;f = 1 MHz; see Figs 1 and 3 1.9 2.25 pF Cd( 1V ) Cd (28V ) capacitance ratio f = 1 MHz 8.2 10 Cd( 19V ) Cd (28V ) capacitance ratio f = 1 MHz 1.2 – capacitance matching VR = 0.5 to 28 V; in a sequence of 4 diodes (gliding) – 1 % VR= 0.5 to 28 V; in a sequence of 15 diodes – 2 % ∆C d Cd (gliding) Note 1. VR is the value at which Cd = 9 pF. BB149–1/2 LESHAN RADIO COMPANY, LTD. BB 149 f = 1 MHz; Tj = 25 °C. Fig.1 Diode capacitance as a function of reverse voltage; typical values. Tj = 0 to 85 °C. Fig.2 Reverse current as a function of junction Fig.3 Temperature coefficient of diode temperature; maximum values. capacitance as a function of reverse voltage; typical values. BB149–2/2