XC6209 Series
High Speed LDO Regulators, Low ESR Cap. Compatible, Output On/Off Control
!
OPERATIONAL EXPLANATION
Output voltage control with the XC6209 series :
V
IN
CE
ON/OFF
Control
each circuit
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.
Current
Limiter
V
OUT
R2
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.
R1
Voltage
Reference
V
SS
Low ESR Capacitors
With the XC6209 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 XC6209 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 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 XC6209B/F 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 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.
Data Sheet
11
TOREX [ TOREX SEMICONDUCTOR ]
