Owner manual

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,
R1
OV and R1UV are 2.00 KΩ 1%. If PI2002-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(UV
TH)
I
RUV
2.1.2 Set R1UV and R1OV value based on system
allowable minimum current and 1% error;
I
RUV ≥ 100 µA
R2UV =R1UV
(
V(UV)
–1
)
V(UVTH)
Where:
V(UV
TH) : UV threshold voltage
V(UV) : UV voltage set (0.5 V typ)
I
RUV: R1UV current
R2OV =R1OV
(
V(OV)
–1
)
V(OVTH)
Where:
V(OV
TH) : OV threshold voltage
V(OV) : OV voltage set (0.5 V typ)
I
ROV: R1OV current
PI2002
UV
OV
FT
FT
V_Logic
GND
R2
UV
R1UV
R2
OV
R1OV
Vin
Figure 4 – UV & OV two-resistor divider configuration
Ref. Desg. U1 U2
R1UV R3 R14
R2UV R1 R12
R1OV R4 R15
R2OV R2 R13
Picor Corporation • www.picorpower.com PI2002-EVAL1 User Guide Rev 1.0 Page 5 of 11
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)
–1
)
= 2.00 KΩ
*
(
1.8 V
–1
)
= 5.20 KΩ (or 5.23 KΩ % standard value)
V(UVTH) 0.5 V
R2OV= R1OV
(
V(OV)
–1
)
= 2.00 KΩ
*
(
2.2 V
–1
)
= 6.80 KΩ (or 6.81 KΩ % standard value)
V(OVTH) 0.5 V