PI2001-EVAL1 Datasheet, PDF (5/11 Pages) Vicor Corporation – PI2001-EVAL1 Active ORing

Before initial power-up follow these steps to configure the
evaluation board for specific end application requirements:
2.0 Undervoltage (UV) and Overvoltage (OV) resistors set up:
2.1 UV and OV programmable resistors are configured
for a 3.3 V Vin (BUS voltage) application in a
two-resistor voltage divider configuration as shown in
Figure 4. UV is set to 2.6 V and OV is set for 3.8 V,
R1OV and R1UV are 2.00KΩ 1%. If PI2121-EVAL1 is
required to be used in a different Vin voltage . .
application please follow the following steps to
change the resistor values.
2.1.1 It is important to consider the maximum current
that will flow in the resistor divider and
maximum error due to UV and OV input .
current.
R1UV = ^V(UVTH)
IRUV
2.1.2 Set R1UV and R1OV value based on system
allowable minimum current and 1% error;
IRUV ≥ 100 µA
( ) R2UV = R1UV V(UV) –1
V(UVTH)
Where:
V(UVTH) : UV threshold voltage
V(UV) : UV voltage set (0.5 V typ)
IRUV: R1UV current
Vin
R2_OV
R1OV
R2_UV
R1UV
V_Logic
UV
PI2001
OV
FT FT
GND
Ref. Desg.
R1UV
R2UV
R1OV
R2OV
U1
U2
R5
R12
R1
R8
R6
R13
R2
R9
Figure 4 – UV & OV two-resistor divider configuration
( ) R2OV = R1OV V(OV) –1
V(OVTH)
Where:
V(OVTH) : OV threshold voltage
V(OV) : OV voltage set (0.5 V typ)
IROV: R1OV current
2.1.3 Example for 2.0 V Vin (BUS voltage), to set UV and OV for ±10% Vin set UV at 1.8 V and OV at 2.2 V.
( ) ( ) ^{R2UV= R1UV}
V(UV)
V(UVTH)
–1
= 2.00 KΩ_*
1.8 V _{–1 = 5.20 KΩ (or 5.23 KΩ % standard value)}
0.5 V
( ) ( ) ^{R2OV= R1OV}
V(OV)
V(OVTH)
–1
= 2.00 KΩ_*
2.2 V
0.5 V
–1 = 6.80 KΩ (or 6.81 KΩ % standard value)
Picor Corporation • www.picorpower.com
P12001-EVAL1 User Guide Rev 1.1 Page 5 of 11