LD7750EGN View Datasheet(PDF) - Unspecified

Part Name

Description

Manufacturer

LD7750EGN

High Voltage Green-Mode PWM Controller with Over Temperature Protection

Unspecified 

Protection Resistor on the Hi-V Path

In some Hi-V processes and designs, there may be a

parasitic SCR between HV pin, Vcc and GND. As shown

in Fig. 22, any small negative spike on the HV pin may

trigger this parasitic SCR and latchup between Vcc and

GND. It will easily damage the chip because of the

equivalent short-circuit induced.

With the Leadtrend’s proprietary Hi-V technology, there is

no such parasitic SCR in LD7750E. Fig. 23 shows the

equivalent circuit of LD7750E’s Hi-V structure. The

LD7750E has higher capability to sustain negative voltage

than similar products. Nevertheless, a 39KΩ resistor is

recommended to plant in the Hi-V path as a current limit

resistor, no matter what negative voltage is present in any

situation.

LD7750E

Fig. 22

Fig. 23

Leadtrend Technology Corporation

LD7750E-DS-00 February 2012

14

www.leadtrend.com.tw

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