ATA8404-6DQY Atmel, ATA8404-6DQY Datasheet - Page 9

• Manufacturer Part Number: ATA8404-6DQY
• Description: IC TRANSMITTR ASK/FSK UHF 10TSSO
• Manufacturer: Atmel

Specifications of ATA8404-6DQY

• Frequency: 313MHz ~ 317MHz
• Applications: Home Automation, Remote Sensing, RKE
• Modulation Or Protocol: ASK, FSK
• Data Rate - Maximum: 40 kBaud
• Power - Output: 4dBm ~ 8dBm
• Current - Transmitting: 8.4mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 2 V ~ 3.6 V
• Operating Temperature: -55°C ~ 85°C
• Package / Case: 10-TSSOP
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.6V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Memory Size: -
• Lead Free Status / Rohs Status: Compliant

4.4
4.5
4.5.1
4.5.2
9136C–INDCO–10/09
Accuracy of the Center Frequency
CLK Output
Clock Pulse Take-over by Microcontroller
Output Matching and Power Setting
The imaginary part of the impedance in large signal steady state oscillation IM
the pin 7 (XTO1), causes some additional frequency tolerances, due to pulling of the XTO
oscillation frequency. These tolerances have to be added to the tolerances of the crystal itself
(adjustment tolerance, temperature stability and ageing) and the impact on the center fre-
quency due to tolerances of C
C
frequency and choosing C
quency, and the frequency deviation is as expected. Then, from the nominal value, the IM
has ±90
f
results. If using crystals with other C
the same way. For example, a lower C
11.87 ppm, where a higher C
An output CLK signal of 1.64 MHz (ATA8404 operating at 315 MHz) and 1.69 MHz (ATA8405
operating at 433.92 MHz) is provided for a connected microcontroller. The delivered signal is
CMOS-compatible with a High and Low time of >125 ns if the load capacitance is lower than
20 pF. The CLK output is Low in power-down mode due to an internal pull-down resistor. After
enabling the PLL and XTO the signal stays Low until the amplitude of the crystal oscillator has
reached 35% to 80% of its amplitude. Then, the CLK output is activated synchronously with its
output signal so that the first period of the CLK output signal is a full period.
The clock of the crystal oscillator can be used for clocking the microcontroller. Atmel’s
ATARx9x microcontroller family provides the special feature of starting with an integrated RC
oscillator to switch on the ATA8404/ATA8405’s external clocking and to wait automatically until
the CLK output of the ATA8404/ATA8405 is activated. After a time period of 250 µs the mes-
sage can be sent with crystal accuracy.
The output power is set by the load impedance of the antenna. The maximum output power is
achieved with a load impedance of Z
Z
deliver the DC current (see
The power amplifier delivers a current pulse and the maximum output power is delivered to a
resistive load if the 0.66 pF output capacitance of the power amplifier is compensated by the
load impedance.
At the ANT1 pin, the RF output amplitude is about V
The load impedance is defined as the impedance seen from the ATA8404’s ANT1, ANT2 into
the matching network. Do not mix up this large-signal load impedance with a small-signal input
impedance delivered as an input characteristic of RF amplifiers.
The latter is measured from the application into the IC instead of from the IC into the applica-
tion for a power amplifier.
XTO
Load, opt
Switch
= 13.56 MHz and C
and C
= 280 + j310 (ATA8405) at 433.92 MHz. A low resistive path to V
tolerances, using the pulling formula P = –IM
Stray
should be absorbed into the C
M
4
Figure 4-6 on page
= 4.4 fF an additional frequency tolerance of P = ±16.86 ppm
and C
M
= 5.5 fF increases the tolerance to 21.07 ppm.
4
ATA8404/ATA8405 [Preliminary]
, C
5
5
, so that the XTO center frequency equals the crystal fre-
, C
M
the additional frequency tolerance can be calculated in
Switch
Load, opt
M
= 3.1 fF will reduce the frequency tolerance to
and C
= 380 + j340 (ATA8404) at 315 MHz and
10).
4
and C
Stray
S
– 0.5V.
. The nominal value of IM
5
values by using a crystal with known
X T O
C
M
S
XTO
is required to
XTO
f
, seen into
X T O
= 110 ,
with
XTO
9