YB1200R
150mA High PSRR with Auto-Discharge LDO Regulator
P-channel MOSFET pass transistor. This
provides several advantages over similar
designs using a PNP pass transistor,
including low operating power and longer
battery life. The YB1200R consumes only
60µA of quiescent current under most
conditions.
Output Short-Circuit Current Limit
The YB1200R includes a current limiter,
which monitors and controls the pass
transistor’s gate voltage, limiting the output
current to about 200mA, for example, in a
short-circuit output situation.
Shutdown
The YB1200R also features a low-power
active shutdown mode. It has a switch that
turns off the device when disabled. This
allows the output capacitor and load to
discharge and de-energize the load. In the
shutdown mode, the internal functional
blocks, such as voltage reference and the
error amplifier, are turned off completely,
and the quiescent current is less than 1µA.
Thermal Protection Shutdown
The thermal protection shutdown function
protects the device from operating in over
temperature condition. When the junction
temperature exceeds +160°C, the thermal
sensor signals the shutdown logic, turning
off the pass transistor and allowing the IC
to cool down. The thermal sensor turns the
pass transistor on again after the IC’s
junction temperature drops to +140°C.
Auto-Discharge Circuitry
The YB1200R deploys a NMOS connecting
between VOUT and ground. When EN pin
is pulled low, the NMOS is activated by an
inverted signal from EN. The charge kept
on output capacitor is discharged quickly
through the NMOS. It prevents the system
from abnormal operation at the beginning
of shudown mode.
Soft-Start Circuitry
The YB1200R includes a soft-start circuitry
to limit inrush current at turn-on. During
power up, the output capacitor and output
load are charged with a reduced output
current. Shortly after the initial power up,
the soft-start feature is terminated and
normal operation is resumed.
Application Information
Enable/Shutdown
The YB1200R comes with an active-high
enable pin that allows the regulator to be
enabled. Forcing the enable pin low
disables the regulator and puts it into the
shutdown mode. This pin cannot be left
floating as it may cause an undetermined
state.
Input/Output Capacitor
It is recommended to use a 1.0µF capacitor
on the YB1200R input and a 1.0µF
capacitor on the output. For high regulation
performance, larger input capacitor values
and lower ESRs provide better noise
rejection and line-transient response. The
output noise, load-transient response,
stability, and power-supply rejection can be
improved by using large output capacitors.
Low ESR ceramic capacitors provide
optimal performance and save space.
YB1200R MRev. 1.0
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YOBON [ YOBON TECHNOLOGIES,INC. ]
