BB178

LESHAN RADIO COMPANY, LTD. VHF variable capacitance diode BB 178 FEATURES · Excellent linearity · Excellent matching to 2% DMA · Ultra small plastic SMD package · C 28: 2.6 pF; ratio: 15 · Very low series resistance. APPLICATIONS · Electronic tuning in VHF television tuners, band B up to 460 MHz · Voltage controlled oscillators(VCO). DESCRIPTION The BB178 is a planar technology variable capacitance diode, in a SOD523 (SC-79) package. The excellent matching performance is achieved by gliding matching and a direct matching assembly procedure. 1 2 SOD523 SC-79 MARKING CODE:8 8 MAX. 32 35 20 +150 +125 UNIT V V mA °C °C MAX. – – 0.65 – – 1.3 – 1.08 – TYP. 10 200 0.8 42.35 2.754 – – – 2 % nA nA Ω pF pF 1 CATHODE 2 ANODE 1 2 LIMITING VALUES In accordance with the Absolute Maximum Rating System (IEC 134). SYMBOL VR V RM IF T stg Tj PARAMETER continuous reverse voltage peak reverse voltage continuous forward current storage temperature operating junction temperature CONDITIONS in series with a 10 kΩ resistor MIN. – – – –55 –55 ELECTRICAL CHARACTERISTICS T j =25°C unless otherwise specified. SYMBOL IR rs Cd C d(1V) C d(2V) C d(1V) C d(28V) C d(25V) C d(28V) ∆C d Cd PARAMETER reverse current diode series resistance diode capacitance CONDITIONS V R = 30 V; see Fig.2 V R = 30 V; T j =85°C; see Fig.2 f = 100 MHz; V R is the value at which Cd =30 pF V R = 1 V; f = 1 MHz; see Figs 1and 3 V R = 28 V; f = 1 MHz; see Figs 1and 3 f = 1 MHz f = 1 MHz f = 1 MHz V R = 1 to 28 V; in a sequence of 15 diodes(gliding) MIN. – – – 34.65 2.361 – 13.5 – – UNIT capacitance ratio capacitance ratio capacitance ratio capacitance matching BB178–1/2 LESHAN RADIO COMPANY, LTD. BB 178 50 40 C d ( pF ) 30 20 f = 1 MHz; T j =25°C 10 0 10 –1 1 10 10 2 V R( V ) Fig.1 Diode capacitance as a function of reverse voltage; typical values. 10 3 10 –3 I R (nA) TC d ( K -1 ) 10 2 10 –4 T j = 0 to 85 °C. 10 0 50 100 10 –5 10 –1 1 10 T j ( °C ) V R( V ) Fig.2 Reverse current as a function of junction temperature; maximum values. Fig.3 Temperature coefficient of diode capacitance as a function of reverse voltage; typical values. BB178–2/2