www.RFM.com
Technical s1.678.684.2000
Page 27 of 82
© 2010-2012 by RF Monolithics, Inc.
E-mail:
DNT90 Integration Guide - 05/10/12
6.0 DNT90 Hardware
1 8
1 9
2 0
2 1
2 2
2 3
1 7
1 6
2 4
2 5
2 6
1 5
1 4
1 3
1 2
1 1
1 0
9
8
7
6
5
D N T 9 0 B l o c k D i a g r a m
2 7
M i c r o c o n t r o l l e r
4
3
2
1
R e g
G N D
A C T ( D I A G _ T X )
/ D C D ( D I A G _ R X )
G P I O 0
R A D I O _ T X D
R A D I O _ R X D
G P I O 4 ( / H O S T _ C T S )
G P I O 5 ( / H O S T _ R T S )
D A C 0
G P I O 2
G P I O 1
G P I O 3 ( D A V )
D A C 1
V C C
G N D
G
N
D
/R
E
S
E
T
A
D
C
1
M
IS
O
M
O
S
I
/S
S
S
C
LK
3.3
V
_O
U
T
A
D
C
_E
X
T_
R
E
F
A
D
C
0
+ 3 . 3 V
2 8
2 9
3 0
G
N
D
G
N
D
R
S
V
D
T R C 1 0 3
I R Q 0
I R Q 1 / D C L K
D A T A
P L L _ L O C K
S C K
S D I
S D O
n S S _ D A T A
n S S _ C O N F I G
S A W F i l t e r
a n d
P o w e r A m p
R
S
V
D
R
S
V
D
Figure 6.0.1
The major components of the DNT90 include an RFM TRC103 900 MHz FHSS transceiver and a low cur-
rent 8-bit microcontroller. The DNT90 operates in the 902 to 928 MHz ISM band. There are four se-
lectable hopping patterns providing compatibility with frequency allocations in North America, South
America and Australia. The DNT90 also has two selectable RF output power levels: +16 dBm (40 mW)
and +22 dBm (158 mW).
The DNT90 receiver is protected by a low-loss SAW filter, providing an excellent blend of receiver sensi-
tivity and out-of-band interference rejection that is especially important in outdoor applications.
The DNT90 provides a variety of hardware interfaces. There are two serial ports plus one SPI port. Either
the primary serial port or the SPI port can be selected for data communications. The second serial port is
dedicated to diagnostics. The primary and diagnostic serial ports support most standard baud rates up to
250 kbps. The SPI port supports data rates up to 500 kbps. Also included are three ADC inputs, two DAC
outputs and six general-purpose digital I/O ports. Four of the digital I/O ports support an optional interrupt-
from-sleep mode when configured as inputs.
There are four module configurations in the DNT24 Series:
- The DNT90C is designed for use with an external antenna and for solder reflow mounting.
- The DNT90P is designed for use with an external antenna and for plug-in connector mounting.
- The DNT90CA has a built-in chip antenna and is designed for solder reflow mounting.
- The DNT90PA has a built-in chip antenna and is designed for plug-in connector mounting.