ADXL180
Rev. 0 | Page 13 of 56
PHYSICAL INTERFACE
APPLICATION CIRCUIT
A typical application circuit is shown in Figure 6. The two capa-
citors shown in Figure 6 are typically ceramic, X7R, multilayer
SMT capacitors. Maximum recommended values of ESR and
ESL are 250 mΩ and 2 nH, respectively. Capacitor tolerances of
±10% are recommended.
CURRENT MODULATION
When the ADXL180 device is powered on, it uses current
modulation to transmit data. Normally, the device pulls I
IDLE
current. When modulating, an additional current of I
MOD
is
pulled from the sensor bus. See Figure 7.
ADXL180
V
BP
V
DD
V
BP
SUPPLY AND
V
BN
CONFIGURATION
BUS
V
BN
C
VDD
100nF
C
B
10nF
07
54
4-
02
6
Figure 6. Application Circuit
I
IDLE
t
B
t
A
90%
I
MOD
TIME
10%
50%
t
RF
07
54
4-
0
27
Figure 7. Communication Current Modulation Timing
