Cirrus Logic CDB5467U - Manual (Page 4)

CDB5467U
4 DS714DB1
1.3 Analog Section
The CDB5467U evaluation board provides screw-type terminals (J21, J23, J27, & J28) to connect input
signals to the voltage and current channels. The screw terminals are labels as VIN2-, VIN2+, VIN1-,
VIN1+, IIN1+, IIN1-, and IIN2+, IIN2-. An R-C network at each channel input provides a simple anti-alias
filter.
The evaluation board provides three voltage reference options for VREFIN to the CS5467. The three volt-
age reference options include: VREFOUT from CS5467, the on-board +2.5V reference, and external
REF+ (screw terminal J14).
Table 1 and Table 2 illustrate the options available for VREFIN. With a jumper
on J25 in the position labeled VREFOUT, the reference is supplied by the on-chip voltage reference. With
a jumper on J25 in the position labeled VREF, the reference is supplied by an off-chip voltage reference.
Table 2 illustrates the options available for VREF. With a jumper on J12 in position LT1019, the LT1019
provides a +2.5V reference (the LT1019 was chosen for its low drift - typically 5 ppm/°C). By setting the
jumper on J12 to position REF+, an external voltage reference is supplied via screw terminal J14's REF+
input.
The three input signal options for the voltage (VIN1±, VIN2±) and current (IIN1±, IIN2±) channels input
include: an external signal (screw terminals J21, J23, J27, and J28), GND, or VREF. Table3 illustrates the
options available. By installing jumpers on J11 to position VIN2-, J7 to position VIN2+, J17 to position
VIN1-, J22 to position VIN1+, J24 to position IIN1+, J26 to position IIN1-, J20 to position IIN2+, and J19
to position IIN2-, the input voltage signal is supplied from the screw terminals J21, J23, J27, and J28. With
a jumper on J11, J7, J17, J22, J24, J26, J20 and J19 in the GND position, the inputs are connected to
Reference Description J25
VREFOUT
Selects On-chip
Reference (25 ppm/ ° C)
VREF
Selects External or
LT1019 Reference(J12)
Table 1. Internal Voltage Reference Selection for VREF
Reference Description J12
LT1019
Selects On-board
LT1019 Reference
(5 ppm/ ° C)
REF+
Selects External
Reference Source
(J14)
Table 2. External Voltage Reference Selection for VREF
O
O VREF
VREFIN
VREFOUT
(Default)
O
O VREF
VREFIN
VREFOUT
O VREF
O O VREF
LT1019
REF+
O VREF
O O VREF
LT1019
REF+
(Default)