NCP45491PMNGEVB
2
These gain settings can be adjusted by changing the bus
divider resistors, and the shunt current network resistors as
desired.
Board Connections & Jumper Settings
The following board to bench equipment connections are
required for demonstration of 6 channel power monitoring.
Make all board connections with supplies and loads
disabled. Take adequate precautions when working with
high current and high voltage applications. Table 3 below
defines all default board connections and their purpose.
Table 4 below defines all default jumper connections and
their purpose.
Table 3. EVALUATION BOARD DEFAULT CONNECTIONS
Connection
Connect To
0
Purpose
VBUS1 (banana)
12 V supply
Provides channel 1 and channel 2 bus voltages
VBUS2 (banana)
6 V supply
Provides channel 3 and channel 4 bus voltages
VBUS3 (banana)
8 V supply
Provides channel 5 and channel 6 bus voltages
LOAD1 & GND (banana)
1 A load current
Provides channel 1 load current
LOAD2 & GND (banana)
0.5 A load current
Provides channel 2 load current
LOAD3 & GND (banana)
1 A load current
Provides channel 3
LOAD4 & GND (banana)
0.5 A load current
Provides channel 4 load current
LOAD5 & GND (banana)
1 A load current
Provides channel 5 load current
LOAD6 & GND (banana)
0.5 A load current
Provides channel 6 load current
VCC & GND
3.3 V
Provides NCP45491 supply
MUX_SEL (sma)
3.3 V to 0 V signal generator
Channel mux select input
EN (sma/header)
3.3 V to 0 V signal generator or tied to GND
NCP45491 enable input. Active low
DIFF_OUT_P (sma)
Oscilloscope
Differential output (positive)
DIFF_OUT_N (sma)
Oscilloscope
Differential output (negative)
1. All connections to the board have an accompanying ground connection. Use all ground connections with the evaluation board being the
center of a star ground to avoid ground loops.
2. Connect to DIFF_OUTN/P signals with either 2 SMA to BNC cables to an oscilloscope (where the subtraction of the 2 signals gives the
differential voltage), or connect to the DIFF_OUT* test loops with a twisted pair or differential probe. Connecting in this manner mitigates
noise via EMI.
3. SH_INx inputs need to be driven to a voltage between VCC and 26 V, even for unused channels. Jumpers 1, 2, 5, and 8 provide a means
to connect unused channels to VCC. If a channel is not in use, the jumper should be switched to the VCC position and the SH_Ox jumper
should be removed to float the SH_Ox pin.
Table 4. DEFAULT JUMPER DEFINITION
Jumper
Default Setting
Function
J3, J6, J11, J12, J13, J14
Shorted [1,2]
Connects channel bus voltages. [2,3] connection sets
bus voltage to 3.3 V if that channel is not in use
J4, J5, J9, J7, J8, J10
Shorted
Connects SH_Ox. Short for all used channels
J2
Shorted [1,2]
SKIP input connection
J1
Open
SMD jumper that can be shorted to tie EN to GND
4. The number of used channels for each NCP45491 chip must match. The default connects set 3 channels for each chip for a total of 6
channels. Up to 8 can be used.
