XC6212 Series
High Speed LDO Regulators, Low ESR Cap. Compatible, Output ON/OFF Control
!
OPERATIONAL EXPLANATION
Output voltage control with the XC6212 series :
V
IN
CE
ON/OFF
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 VOUT pin, is then
driven by the subsequent output signal. The output voltage at the
VOUT 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.
each circuit
Current
Limiter
V
OUT
R2
R1
Voltage
Reference
V
SS
Low ESR Capacitors
With the XC6212 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 (CL) is connected as close as possible to the
output pin (VOUT) and the VSS pin. Please use an output capacitor with a capacitance value of at least 1µF. Also, please connect an input capacitor
(CIN) of 0.1µF between the VIN pin and the VSS pin in order to ensure a stable power input.
Current Limiter, Short-Circuit Protection
The XC6212 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 XC6212 series. In shutdown mode, output at the VOUT pin will be
pulled down to the VSS level via R1 & R2. The operational logic of the IC's CE pin is selectable (please refer to the selection guide on page 3). Note
that as the standard XC6212B Type is ' Active High/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 VIN voltage or a VSS 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
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 VIN and VSS wiring in particular.
3
Please wire the input capacitor (CIN) and the output capacitor (CL) as close to the IC as possible.
Semiconductor Ltd.
7
TOREX [ TOREX SEMICONDUCTOR ]
