Philips Semiconductors Product specification Voltage regulator diodes BZX79 series THERMAL CHARACTERISTICSSYMBOLPARAMETERCONDITIONSVALUEUNIT Rth j-tp thermal resistance from junction to tie-point lead length 8 mm. 300 K/W Rth j-a thermal resistance from junction to ambient lead length max.; see Fig.2 and note 1 380 K/W Note 1. Device mounted on a printed circuit-board without metallization pad. GRAPHICAL DATA MBG930 103 handbook, full pagewidth δ = 1 Rth j-a (K/W) 0.75 0.50 0.33 102 0.20 0.10 0.05 0.02 0.01 10 ≤0.001 t t p p δ T = T 1 10−1 1 10 102 103 104 105 tp (ms) Fig.2 Thermal resistance from junction to ambient as a function of pulse duration. 2002 Feb 27 6 Document Outline FEATURES APPLICATIONS DESCRIPTION LIMITING VALUES ELECTRICAL CHARACTERISTICS THERMAL CHARACTERISTICS GRAPHICAL DATA PACKAGE OUTLINE SOD27 DATA SHEET STATUS DEFINITIONS DISCLAIMERS