PI2061 Datasheet, PDF (13/16 Pages) Vicor Corporation – High Side High Voltage Load Disconnect Switch Controller IC

Not Recommended for New Designs
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Typical application Example 2:
Requirement:
+48V Load Switch with Enable Function
Bus Voltage = +48V (+36V to +55V)
Maximum Load Current = 5A
Minimum Trip current = 6A
Maximum Ambient Temperature = 60°C
Solution:
PI2061 with a suitable MOSFET should be used and
configured as shown in Figure 16.
Select a suitable N-Channel MOSFET: Select a MOSFET
with voltage rating higher than the input voltage, Vin, plus
any expected transient voltages, with a low R_DS(on) that is
capable of supporting the full load current with margin. For
instance, a 100V rated MOSFET with 10A current capability
is suitable. An exemplary MOSFET having these
characteristic is IRF7853PbF from International Rectifier.
Maximum Junction temperature
Recalculate maximum R_DS(on) at 95°C.
At 95°C R_DS(on) will increase by 50%:
at maximum at 95°C
Maximum Junction temperature after 10s
For continuous operation refer the MOSFET datasheet for
R_θJA under continuous operation and use in place of
50°C/W.
From the IRF7853PbF datasheet:
N-Channel MOSFET
V_DS= 100V
I_D = 8.3A maximum continuous drain current at 25°C
I_D-PULSE = 66A pulsed drain current
V_GS(MAX) =±20V
R_θJA= 50°C/W on 1in² copper, t ≤ 10seconds
R_θJA for continuous operation not provided
R_DS(on)=14.4m typical at V_GS=10V, T_J=25°C
R_DS(on)=18m maximum at V_GS=10V, T_J=25°C
VC Bias Resistors:
Select 7.5k resistor
Select Sense Resistor:
Rs power dissipation at maximum operating current
Maximum trip current
Select 10k resistor
Power dissipation of R_VC and R_PG:
Power dissipation:
R_DS(on) is 18m maximum at 25°C & 10 V_GS and will increase
as the temperature increases. Add 20°C to maximum
ambient temperature to compensate for the temperature
rise due to power dissipation. At 80°C (60°C + 20°C) R_DS(on)
will increase by 40%.
at maximum at 80°C
Recommended Schottky: PMEG4005EJ from NXP or
equivalent
Picor Corporation • picorpower.com
PI2061
Rev 1.4
Page 13 of 16