
8/23 
XC6219/6211
 Series
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OPERATIONAL EXPLANATION
<Output Voltage Control> 
The voltage divided by resistors R1 & R2 is compared with the internal reference voltage by the error amplifier. The 
P-channel MOSFET, which is connected to the V
OUT
 pin, is then driven by the subsequent output signal. The output 
voltage at the V
OUT
 pin is controlled and stabilized by a system of negative feedback. The current limit circuit and short 
protect circuit operate in relation to the level of output current. Further, the IC's internal circuitry can be shutdown via the 
CE pin's signal 
<Low ESR Capacitors> 
With the XC6209/6212 series, a stable output voltage is achievable even if used with low ESR capacitors as a phase 
compensation circuit is built-in. In order to ensure the effectiveness of the phase compensation, we suggest that an output 
capacitor (C
L
) is connected as close as possible to the output pin (V
OUT
) and the V
SS
 pin. Please use an output capacitor 
with a capacitance value of at least 1
μ
F. Also, please connect an input capacitor (C
IN
) of 0.1
μ
F between the V
IN
 pin and the 
V
SS
 pin in order to ensure a stable power input.  
Stable phase compensation may not be ensured if the capacitor runs out capacitance when depending on bias and 
temperature.  In case the capacitor depends on the bias and temperature, please make sure the capacitor can ensure the 
actual capacitance. 
<Current Limiter, Short-Circuit Protection> 
The XC6219/6211 series includes a combination of a fixed current limiter circuit & a foldback circuit, which aid the operations 
of the current limiter and circuit protection. When the load current reaches the current limit level, the fixed current limiter 
circuit operates and output voltage drops. As a result of this drop in output voltage, the foldback circuit operates, output 
voltage drops further and output current decreases. When the output pin is shorted, a current of about 50mA flows. 
<CE Pin> 
The IC's internal circuitry can be shutdown via the signal from the CE pin with the XC6219/6211 series. In shutdown mode, 
output at the V
OUT
 pin will be pulled down to the V
SS
 level via R1 & R2. The operational logic of the IC's CE pin is selectable 
(please refer to the selection guide). Note that as the standard XC6219/6211B type's regulator 1 and 2 are both ' High 
Active/No Pull-Down', operations will become unstable with the CE pin open. Although the CE pin is equal to an inverter input 
with CMOS hysteresis, with either the pull-up or pull-down options, the CE pin input current will increase when the IC is in 
operation. We suggest that you use this IC with either a V
IN
 voltage or a V
SS
 voltage input at the CE pin. If this IC is used with 
the correct specifications for the CE pin, the operational logic is fixed and the IC will operate normally. However, supply 
current may increase as a result of through current in the IC's internal circuitry.
1. Please use this IC within the stated absolute maximum ratings. The IC is liable to malfunction should the ratings be 
exceeded. 
2. Where wiring impedance is high, operations may become unstable due to noise and/or phase lag depending on output 
current. Please keep the resistance low between V
IN
 and V
SS
 wiring in particular. 
3. Please wire the input capacitor (C
IN
) and the output capacitor (C
L
) as close to the IC as possible. 
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NOTES ON USE