CDB5510 Datasheet, PDF (4/22 Pages) Cirrus Logic – Evaluation Board and Software

CDB5510/11/12/13
ically 5ppm/°C). By setting HDR3’s jumper to the
“REF” position, the user can supply an external
voltage reference to J1’s REF input. V- is also pro-
vided at connector J1 to allow an easy connection
to the negative supply. (Application Note 4 on Cir-
rus Logic’s web site details various voltage refer-
ences).
Reference Description
HDR3
V+
Selects Analog
Power Supply
V+ O O VREF
LT1019 O O VREF
REF O O VREF
LT1019
Selects on board
V+ O O VREF
LT1019 Reference LT1019 O O VREF
(5ppm/°C)
REF O O VREF
Selects external
V+ O O VREF
EXTERNAL reference source LT1019 O O VREF
connected to J1
REF O O VREF
Table 2. Voltage Reference Selection Using HDR3
1.5 Clocking Options
The CS5510/11/12/13 are very simple ADCs, in-
tended to continuously convert and output data
when not in sleep mode. The CS5510 and CS5512
require an external clock signal on the SCLK input
pin to run properly. The CDB5510 evaluation
board provides three options for this clock source:
1) The microcontroller can be used to generate a
clock for the CS5510/12. The microcontroller’s
clock can be selected by removing the jumper from
HDR7 on the CDB5510 board, and selecting the
“CS5510/12 Clock from microcontroller” option in
the software. The DIP switches on the evaluation
board should be set as shown in the “CS5510/12
Clock from 8515” section of Table 3. The clock
frequency can be selected by changing the “Oscil-
lator Frequency” box in the software. Note that the
frequency options are limited by the microcontrol-
ler’s counter/timer circuitry, which divides the
3.6864 MHz clock by integer values to produce the
clock output.
2) The 32 kHz on-board oscillator circuit (shown in
Figure 11) can be used by connecting HDR7 on the
CDB5510 board and selecting the “On-board or ex-
ternal clock source” option in the software. The
DIP switches on the evaluation board should be set
as shown in the “CS5510/12 External Clock” sec-
tion of Table 3.
3) An external clock can be provided by the user,
and connected to the SCLK post on HDR7. The
“On-board or external clock source” option in the
software should be selected when using an external
clock source, and the DIP switches on the evalua-
tion board should be set as shown in the
“CS5510/12 External Clock” section of Table 3.
The CS5511 and CS5513 include an internal oscil-
lator, and as such, need no external oscillator to
run. When using the CS5511 or CS5513, HDR7 on
the CDB5510 board should be left disconnected,
and the “CS5511/13 Internally Clocked” option
should be selected in the software. Likewise, the
Eval Board Mode
CS5511/13 Internally Clocked
X is OPEN
A is OPEN
B is OPEN
CS5510/12 Clock From 8515
X is OPEN
A is CLOSED
B is CLOSED
CS5510/12 External Clock
X is OPEN
A is OPEN
B is CLOSED
RS-232 Test Mode
X is CLOSED
A is CLOSED
B is CLOSED
SW1 Settings
1
2
3
OPEN
XAB
1
2
3
OPEN
XAB
1
2
3
OPEN
XAB
1
2
3
OPEN
XAB
Table 3. DIP Switch Settings
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DS337DB2