
10/25
XC6209/6212
Series
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 strengthen 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.
■
OPERATIONAL EXPLANATION
Output voltage control with the XC6209/6212 series:
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 & 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 XC6209/6212 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 XC6209/6212 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 XC6209B type is ' 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’s in
operation. We suggest that you use this IC with either a VIN 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 IC will operate normally. However, supply current may
increase as a result of through current in the IC's internal circuitry
■
NOTES ON USE