YB1901
2.0A High-Side Power Switch with Flag
between rising and falling. That UVLO
shuts down the chip when input voltage
drops below 2.4V and allows starting up
the chip when input voltage above 2.6V.
Short-Circuit Protection
If the V
OUT
pin is connected to ground or
nearly ground level by mistake, the
short-circuit protection circuit will come
active and put a current limit over the
switch to protect the switch from
over-current. The current limit is set around
1.5A.
Overload Current Limit
The YB1901 is designed to work below
2.0A. If the current load outgrows 2.0A, it
will trigger the Overload Current Limit
Circuitry. The max current limit is set at
2.0A. If the protection circuit is activated, it
send out a fault signal from the OCB pin. It
does not shutdown the circuit.
Thermal Shutdown
The thermal shutdown is deployed to
protect the switch from damage if the
silicon temperature rises above 135°C
approximately. If the circuit is triggered, the
chip will turn on again when the silicon
temperature drops around 20°C below.
Fault Flag
There is a fault flag signal (OCB) available
with YB1901 to indicate the occurrence of
abnormal
operation.
The
abnormal
operation includes Short-Circuit, Thermal
shutdown and Overload Current Limit.
When the fault happens and lasts for more
than 7.5ms typically, the flag will be
asserted. OCB is designed in open-drain
structure. Connecting a resistor of 100K
ohm to V
IN
is necessary for the pin to signal
(active low) a faulty condition.
Application Information
The YB1901 featured very low quiescent
current and very low R
DS(ON)
and making
them ideal for battery-powered applications.
The ENABLE control pin is TTL compatible
and driven by 1.7V beyond making the
YB1901 an ideal level-shifting load switch.
Input Capacitor Selection
A 1μF or larger input
capacitor
is
recommended to prevent load transients
from affecting upstream circuits. C
IN
should
be located as close to the device V
IN
pin as
practically. There is no specific requirement
type of capacitor is recommended.
However, for higher current operation,
ceramic capacitors are recommended for
C
IN
.
Output Capacitor Selection
For proper slew operation, a 0.1μF or
greater is recommended. The output
capacitor has also no specific capacitor
type requirement. If desired, C
OUT
maybe
increased without limit to accommodate
any load transient.
Reverse Output-to-Input Voltage
Conditions and Protection
Under normal conditions, there is no
parasitic diode between the output & input
of the load switch. In case of V
OUT
exceeding V
IN
, there is no excessive
current flow from V
OUT
to V
IN
. This
reverse-blocking ability secures the use of
such a power switch.
8
YB1901 Rev.1.2
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YOBON [ YOBON TECHNOLOGIES,INC. ]
