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SPECIAL FEATURES
Zener characteristic with voltage snap–back
to protect against ESD hits
High avalanche voltage, low leakage and low
capacitance avoid signal attenuation
Compatible to all 5V logic families
Space saving, low inductance TSOC surface
mount package
On–chip 5resistors for isolation at both
anode and cathode terminals
Industrial temperature range
DS9503
ESD Protection Diode with Resistors
www.maxim-ic.com
SYMBOL AND CONVENTI
ONS
PACKAGE OUTLINE
VCA
A
IC
C
TSOC SURFACE MOUNT PACKAGE
6 1
5 2
4 3
TOP VIEW
SIDE VIEW
19-4699; 7/09
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 1–Wire MicroLAN interfaces. In contrast to the
DS9502, the DS9503 includes two 5isolation 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 ESD–protection at their I/O port, the
ESD protection level is raised to more that 27 kV (IEC 801–2 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.
