XC6219 Series
High Speed LDO Regulators, Low ESR Cap. Compatible, ON/OFF Switch
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 VOUT pin, is then driven by the subsequent output signal. The output voltage at the VOUT 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.
V
IN
CE
ON/OFF
Control
each circuit
Current
Limit
V
OUT
R2
R1
Voltage
Reference
V
SS
<Low ESR Capacitors>
With the XC6219 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 XC6219 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 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 2). Note that as the
standard XC6219B 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 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 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.
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 keep the resistance
low between 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.
Data Sheet
9
R000026
TOREX [ TOREX SEMICONDUCTOR ]
