YB1901
2.0A High-Side Power Switch with Flag
Thermal Considerations
The YB1901 is designed to deliver a
continuous load current. The maximum
limit is package power dissipation. At any
given ambient temperature, the maximum
package power dissipation can be
determined by the following equation:
P
D(MAX)
= [ T
J(MAX)
- T
A
] /
θ
JA
Constraints for the YB1901 are maximum
junction temperature T
J(MAX)
= 125
℃
, and
package thermal resistance,
θ
JA
=280
℃
/W.
The maximum continuous output current
for YB1901 depends on package power
dissipation and the R
DS(ON)
of MOSFET at
T
J(MAX)
. Typical conditions are calculated
under normal ambient condition where T
A
=
25
℃
. At 85
℃
, P
D(MAX)
= 143mW. At T
A
=
25
℃
, P
D(MAX)
= 357mW.
The maximum current is calculated by the
following equation:
I
OUT
< (P
D(MAX)
/ R
DS(MAX)
)
1/2
For example, if V
IN
= 5V, R
DS(MAX)
= 100mΩ
and T
A
= 25
℃
, I
OUT(MAX)
= 1.89A.
Thermal Shutdown is employed to protect
the device damage when temperature is
over 120℃.
PCB Layout Consideration
To maximize YB1901 performance, some
board layout rules should be followed:
V
IN
and V
OUT
should be routed using wider
than normal traces, and GND should be
connected to a ground plane. For best
performance, C
IN
and C
OUT
should be
placed close to the package pins.
YB1901 Rev.1.2
www.yobon.com.tw
9
YOBON [ YOBON TECHNOLOGIES,INC. ]
