XCL205 datasheet(13/26 Pages) TOREX

13 / 26 page

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XCL205/XCL206/XCL207

Series

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OPERATIONAL DESCRIPTION (Continued)

＜

CL High Speed Discharge＞

The XCL205B(C)/ XCL206B(C)/ XCL207B(C) series can quickly discharge the electric charge at the output capacitor (CL) when a

low signal to the CE pin which enables a whole IC circuit put into OFF state, is inputted via the N-channel transistor located

between the LX pin and the VSS pin. When the IC is disabled, electric charge at the output capacitor (CL) is quickly discharged so

that it may avoid application malfunction. Discharge time of the output capacitor (CL) is set by the CL auto-discharge resistance

(R) and the output capacitor (CL). By setting time constant of a CL auto-discharge resistance value [R] and an output capacitor

value (CL) as τ(τ=C x R), discharge time of the output voltage after discharge via the N channel transistor is calculated by the

following formula.

V = VOUT(T) x e

–t/τ or t=τln (VOUT(T) / V)

V : Output voltage after discharge

VOUT(T) : Output voltage

t: Discharge time,

: C x R

C= Capacitance of Output capacitor (CL)

R= CL auto-discharge resistance

100

2040

6080

100

Discharge Time ｔ(ms)

CL=10uF

CL=20uF

CL=50uF

Output Voltage Discharge Characteristics

RDCHG=300Ω(TYP.)

XCL205 Datasheet(PDF) 13 Page - Torex Semiconductor