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XC6220

Series

RCE

CE

Error

Amp

-

+

Current

Limit

Thermal

Protection

Green

Operation

ON/OFF

Control

CE

CE/

each

circuit

R1

R2

Voltage

Reference

CE/

The voltage divided by resistors R1 & R2 is compared

with the internal reference voltage by the error amplifier.

pin is then driven by the subsequent output signal. The

by a system of negative feedback. The current limit

circuit and short protect circuit operate in relation to the

level of output current. The GO function monitors the

output current and switches the IC between two

operating modes according to the level of output

current. Further, the IC's internal circuitry can be

shutdown via the CE pin's signal.

<Low ESR capacitor>

The XC6220 series has a built-in phase compensation circuit which means that a stable output voltage is achieved even if

Values required for the phase compensation are shown in the chart below. If a loss of the capacitance happens, the stable

phase compensation may not be obtained. Please ensure to use a capacitor which does not depend on bias or temperature

too much.

INPUT CAPACITOR VALUE

OUTPUT VOLTAGE (V)

4.7μF

10μF

22μF

0.80V～0.95V

×

×

22μF

1.00V～1.45V

47μF

47μF

22μF

1.50V～1.75V

47μF

22μF

10μF

1.80V～2.95V

47μF

6.8μF

6.8μF

3.00V～3.50V

47μF

4.7μF

4.7μF

3.55V～5.00V

47μF

10μF

6.8μF

× No option

<Current Limiter, Short-Circuit Protection>

The XC6220 series includes a fold-back circuit, which aids the operation of the current limiter and circuit protection. When

the load current reaches the current limit level, the fold-back circuit operates and output voltage drops. As a result of this drop

in output voltage, output current also decreases. When the output pin is shorted, a current of about 180mA flows.

<CE Pin>

The IC's internal circuitry can be shutdown via the signal from the CE pin with the XC6220 series. With the XC6220B/D

used with the correct output voltage for the CE pin, the logic is fixed and the IC will operate normally. However, with the

XC6220C/D series, supply current may increase as a result of through current in the IC's internal circuitry when medium

voltage is input.

■

OPERATIONAL EXPLANATION

<GreenOperation>

The XC6220 series always operates in a green operation (GO) mode.

The GO mode enables the IC to switch automatically between the high

speed (HS) mode or the power save (PS) mode according to the level of

output current. The switching point of the HS mode and the PS mode is

or below, the mode changes automatically to the PS mode after a delay

time of hundreds of microseconds. Supply current in light load is greatly

more, the mode changes automatically to the HS mode and the IC

returns to high speed operation.

XC6220x 301

0

10

20

30

40

50

0

5

10

15

20

CE=V