Datasheet HSMS-282x (Broadcom) - 3

Quad Capacitance Linear Equivalent Circuit Model Diode Chip
Capacitance of Schottky diode quads is measured using R an HP4271 LCR meter. This instrument effectively isolates j individual diode branches from the others, allowing ac‑ curate capacitance measurement of each branch or each RS diode. The conditions are: 20 mV R.M.S. voltage at 1 MHz. Avago defines this measurement as “CM”, and it is equiv‑ alent to the capaci tance of the diode by itself. The equiv‑ alent diagonal and adja cent capaci‑tances can then be C calculated by the formulas given below. j In a quad, the diagonal capaci tance is the capacitance be‑ RS = series resistance (see Table of SPICE parameters) tween points A and B as shown in the figure below. The Cj = junction capacitance (see Table of SPICE parameters) diagonal capacitance is calculated using the following 8.33 X 10-5 nT formula Rj = Ib + Is C1 x C 2 C3 x C 4 C where DIAGONAL = _______ + _______ C1 + C 2 C 3 + C 4 Ib = externally applied bias current in amps Is = saturation current (see table of SPICE parameters) 1 The equiv C T = temperature, K ADJACENT alen = C t adjac 1 + ent capacitanc ____________ e is the capacitance between points A and C in the figur C1 x C 2 _______ 1+ 1 C3 1 x C 4 C _______ e below. This capaci‑ n = ideality factor (see table of SPICE parameters) DIAGONAL = –– + –– + –– tance is calcula C t1 ed using the f + C C 2 C 3 + ollo C 4 wing formula 2 C3 C4 Note: 1 To effectively model the packaged HSMS-282x product, C R ADJACENT = C j = 8.33 X 10 -5 nT 1 + ____________ I please refer to Application Note AN1124. b + I s1 1 1 –– + –– + ––
ESD WARNING: Handling Precautions Should Be Taken To Avoid Static Discharge.
C 2 C3 C4
SPICE Parameters
This information does not apply to cross‑over quad di‑ R odes. j = 8.33 X 10 -5 nT I b + I s
Parameter Units HSMS-282x
B V 15 V
A
C pF 0.7 J0
C1 C3
E eV 0.69 G
C
I A 1E‑4 BV I A 2.2E‑8
C
S
2 C4 B
N 1.08 R Ω 6.0 S P V 0.65 B P 2 T M 0.5 3