DNT90C View Datasheet(PDF) - Unspecified
Part Name
Description
MFG CO.
'DNT90C' PDF : 8 Pages View PDF
Pin
Name
23
SCLK
24
ADC2
25
ADC_EXT_
REF
26
RSVD
27
RSVD
28
GND
29
RSVD
30
GND
I/O
Description
I/O
SPI clock signal. This pin is an output when operating as a master, and an input when operating as
a slave.
I
ADC input 2. Direct input when the ADC is operating in single-ended mode, positive differential input rela-
tive to ADC0 when the ADC is operating in differential mode.
ADC external reference voltage pin. The voltage at this pin can be used by the ADCs as a reference for
I/O
ratiometric measurements. With no external voltage or load applied, this pin presents a nominal 2.7 V out-
put through a 2.126 K source resistance. A low impedance external reference voltage in the range of 1 to
2.7 V may be applied to this pin as an option.
- Reserved pin. Leave unconnected.
- Reserved pin. Leave unconnected.
- Connect to the host circuit board ground plane.
- Reserved pin. Leave unconnected.
- Connect to the host circuit board ground plane.
DNT90 Antenna Connector
A U.FL miniature coaxial connector is provided on both DNT90 configurations for connection to the RFIO port. A
short U.FL coaxial cable can be used to connect the RFIO port directly to an antenna. In this case the antenna
should be mounted firmly to avoid stressing the U.FL coaxial cable due to antenna mounting flexure. Alternately,
a U.FL coaxial jumper cable can be used to connect the DNT90 module to a U.FL connector on the host circuit
board. The connection between the host circuit board U.FL connector and the antenna or antenna connector on
the host circuit board should be implemented as a 50 ohm stripline. Referring to Figure 2, the width of this stripline
depends on the thickness of the circuit board between the stripline and the groundplane. For FR-4 type circuit
C ir c u it B o a r d S tr ip lin e T r a c e D e ta il
C opper
S tr ip lin e
T ra c e
C opper
G ro u n d
P la n e
F R -4 P C B
M a te r ia l
F o r 5 0 o h m im p e d a n c e W = 1 .7 5 * H
Figure 2
Trace Separation from Length of Trace Run
50 ohm Microstrip
Parallel to Microstrip
100 mil
150 mil
200 mil
125 mil
200 mil
290 mil
250 mil
300 mil
450 mil
650 mil
Figure 3
board materials (dielectric constant of 4.7), the width of the stripline is equal to 1.75 times the thickness of the cir-
cuit board. Note that other circuit board traces should be spaced away from the stripline to prevent signal cou-
pling, as shown in Figure 3. The stripline trace should be kept short to minimize its insertion loss.
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Page 5 of 7
DNT90 - 11/06/12
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