PI2001 Datasheet, PDF (16/23 Pages) Vicor Corporation – Universal Active ORing Controller IC

Recalculate based on calculated Junction
temperature, 115°C.
At 115°C Rds(on) will increase by 32%.
Rds(on) = 3.5mΩ∗1.32 = 4.62mΩ
T_J
max
=
75°C
+
⎜⎛
⎝
40°C
W
∗
(15A)²
∗
4.62mΩ⎟⎞
⎠
=
116.5°C
3. Vaux: Make sure Vaux voltage is higher than Vin
(power source output) by the voltage required to
fully enhance the MOSFET. Minimum required
Vaux = Vin + Vgs + 0.5V = 3.3V + 4.5V + 0.5V =
8.3V. Since 8.3V is less than the 11V minimum
Aux supply voltage, there is sufficient voltage
available to drive the gate of the MOSFET.
4. SP and SN pins: Connect the SP pin to the
MOSFET source pin and the SN pin to the
MOSFET drain pin.
5. BK pin: Connect the BK pin to the GND pin to
achieve the minimum reverse current response
time.
6. SL pin: Not required, so leave floating.
7. FT pin: Connect to the logic input and to the
logic power supply via a 10KΩ resistor.
8. Program UV and OV to monitor input voltage:
Program UV at 3.0V and OV at 3.6V
Use the three-resistor divider configuration:
I _Ra = 200μA
Ra = ^{V (UVTH )} = ^500mV = 2.5kΩ ^{or 2.49kΩ 1%}
I _Ra
200μA
Rb =
Ra_{⎜⎜⎝⎛}
V
V
(OV
(UV
)
)
− 1_{⎟⎟⎠⎞}
=
2.49kΩ⎜⎛ ^3.6V
⎝ ^3.0V
− 1⎟⎞
⎠
= 498Ω
or 499Ω 1%
Rc
=
(Ra
+
Rb
)_{⎜⎜⎝⎛}
V (UV )
V (UV_TH
)
− 1_{⎟⎟⎠⎞}
= (2.49kΩ + 499Ω)⎜⎛ ^3.0V − 1⎟⎞ = 14.95kΩ
⎝ ^500mV ⎠
or 15kΩ 1%
Figure 15: PI2001 in high side Active ORing
configuration
Picor Corporation • picorpower.com
PI2001
Rev 1.0 Page 16 of 23