ZXLD1370_11 DIODES [Diodes Incorporated], ZXLD1370_11 Datasheet - Page 28

• Manufacturer Part Number: ZXLD1370_11
• Description: 60V HIGH ACCURACY BUCK/BOOST/BUCK-BOOST LED DRIVER CONTROLLER
• Manufacturer: DIODES [Diodes Incorporated]

ZXLD1370
Document number: DS32165 Rev. 3 - 2
Applications Information
Over-voltage Protection
The ZXLD1370 is inherently protected against open-circuit load when used in Buck configuration. However care has to be
taken with open-circuit load conditions in Buck-Boost or Boost configurations. This is because in these configurations there
is no internal open-circuit protection mechanism for the external MOSFET. In this case an Over-Voltage-Protection (OVP)
network should be provided externally to the MOSFET to avoid damage due to open circuit conditions. This is shown in
figure 37 below, highlighted in the dotted blue box.
The zener voltage is determined according to: Vz = V
Take care of the max voltage drop on the Q2 MOSFET gate.
(Continued)
Figure 37. OVP circuit
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ZXLD1370
February 2011