KESTX01
COMPONENT LIST at 433.92MHz
COMPONENTS
R1
R2
C1
L1 and L2
C2
C3
X1
C4
C5
FUNCTION
OUTPUT POWER CONTROL
PLL LOOP FILTER
ANTENNA TUNING
ANTENNA TUNING
PLL LOOP FILTER
PLL LOOP FILTER
PARALLEL RESONANT CRYSTAL
CRYSTAL OSCILLATOR
CRYSTAL OSCILLATOR
VALUE
2.0
4.7
APPLICATION
DEPENDENT
APPLICATION
DEPENDENT
220
10
6.78
18
18
pF
nF
MHz
pF
pF
nH
UNITS
kΩ
kΩ
pF
Note: The value of C1 is split between two capacitors to aid in balancing the antenna loop reducing the level of the second
harmonic
TESTABILITY REQUIREMENTS
This section is a summary of the observability and control-
lability requirements identified to simplify the production test
requirements of the device.
1. Ability to directly drive the XTAL oscillator from the tester (no
crystal). The XTAL2 pin allows direct drive of the oscillator with
an external clock source as shown in Figure 7. Typically a
200mVpk clock signal is AC coupled to produce differential
output on OP and OPb. (C=10nF, R s (Source) <5kΩ)
y
)
p
C
CLK
Rs
XTAL2
OP
OPb
XTAL1
Figure 7 Direct drive of crystal oscillator
2.
Control of the VCO frequency is obtained via the LF1
signal pin. The output of the dividers is tested by measuring
the DC current output of the charge pump (with XTAL2 held
at V
CC
).
3.
DC operation of the power amplifier is observed by
measuring the current through the open collector outputs OUT
and OUTB. The VCO input to the power amplifier is disabled
with VCOTST tied to V
CC
and the bias current being measured
with DATA tied to V
CC
. Toggling DATA input will modulate the
bias current in the power amplifier.
7