Rainbow Electronics DS9503 - Manual

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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 5 Ω
resistors for isolation at both
anode and cathode terminals
§ Industrial temperature range
SYMBOL AND CONVENTIONS
PACKAGE OUTLINE
ORDERING INFORMATION
DS9503P 6-lead TSOC package
DESCRIPTION
This DS9503 is designed as an ESD protection device for 1–Wire MicroLAN interfaces. In contrast to the
DS9502, the DS9503 includes two 5
Ω
isolation resistors on chip. Although 5
Ω
are 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 7.5V 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.
VCA
A
IC
C
TSOC SURFACE MOUNT PACKAGE
3.7 X 4.0 X 1.5 mm
See Mech. Drawings
Section
6 1
5 2
4 3
TOP VIEW
DS9503
ESD Protection Diode with Resistors
www.dalsemi.com
SIDE VIEW