19-4699 7/09 DS9503 ESD Protection Diode with Resistors www.maxim-ic.com ONS SPECIAL FEATURES SYMBOL AND CONVENTI Zener characteristic with voltage snapback C to protect against ESD hits IC VCA High avalanche voltage, low leakage and low capacitance avoid signal attenuation A Compatible to all 5V logic families PACKAGE OUTLINE TSOC SURFACE MOUNT PACKAGE Space saving, low inductance TSOC surface mount package 1 6 Onchip 5resistors for isolation at both 2 5 SIDE VIEW anode and cathode terminals 3 4 Industrial temperature range TOP VIEW ORDERING INFORMATION DS9503P+ 6-lead TSOC package DS9503P+T&R 6-lead TSOC package +Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. DESCRIPTION This DS9503 is designed as an ESD protection device for 1Wire MicroLAN interfaces. In contrast to the DS9502, the DS9503 includes two 5 isolation resistors on chip. Although 5are negligible during communication, they represent a high impedance relative to the conducting diode during an ESD event. Thus, the diode absorbs the energy while the resistors further isolate and protect the circuit at the other side of the package. If used with circuits that already have a strong ESDprotection at their I/O port, the ESD protection level is raised to more that 27 kV (IEC 8012 Reference model). In case of abnormal ESD hits beyond its maximum ratings the DS9503 will eventually fail short thus preventing further damage. During normal operation the DS9503 behaves like a regular Zener Diode. When the voltage exceeds the trigger voltage, the I/V characteristic of the device will snapback allowing the same or higher amount of current to flow, but at a significantly lower voltage. As long as a minimum current or voltage is maintained, the device will stay in the snapback mode. If the voltage or the current falls below the holding voltage or holding current, the device will abruptly change to its normal mode and conduct only a small leakage current. 1 of 3 DS9503 DC CHARACTERISTICS Figure 1 IC/A 1.0 I-TRIGGER 0.8 0.6 0.4 SEE DETAIL DRAWING 0.2 1 2 3 4 5 6 7 8 9 10 11 VCA/V VAV V-TRIGGER DC CHARACTERISTICS DETAIL DRAWING Figure 2 TEST PULSE WAVEFORM Figure 3 TYPICAL APPLICATION Figure 4 2 of 4