9/20

XCL219/XCL220

Series

■OPERATIONAL EXPLANATION (Continued)

<CL High Speed Discharge>

The product 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-ch MOS switch transistor located between the VOUT pin and the GND

pin. When the IC is disabled, electric charge at the output capacitor (CL) is quickly discharged so that it may avoid application

malfunction.

V=VOUT(T) × e - t / τ

t =τLn (VOUT(T) / V)

V : Output voltage after discharge

VOUT(T) : Output voltage

t : Discharge time

τ: CL×RDCHG

CL : Capacitance of Output capacitor

RDCHG : CL auto-discharge resistance,

but it depends on supply voltage.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

0

2

4

6

8

10

12

14

16

18

20

Discharge Time: t(ms)

Vout=1.2V

Vout=1.8V

Vout=3.3V