Rainbow Electronics ATA6286 - Manual (Page 14)

14
4958AS–AUTO–09/06
ATA6285/ATA6286 [Preliminary]
Figure 4-4. Timing FSK Mode with ENABLE Connected to the Microcontroller
4.5.2.2 ASK Mode
The ATA6285/ATA6286 is activated by ENABLE = High, FSK = High and ASK = Low. After acti-
vation the microcontroller is switched to external clocking. After typically 0.6 ms, the CLK driver
is activated automatically (the microcontroller waits until the XTO and CLK are ready). After
another time period of
≤
250 µs, the PLL is locked and ready to transmit. The output power can
then be modulated by means of pin ASK. After transmission, ASK is switched to Low and the
microcontroller returns back to internal clocking. Then, the ATA6285/ATA6286 is switched to
power-down mode with ENABLE = Low and FSK = Low.
Figure 4-5. Timing ASK Mode with ENABLE Connected to the Microcontroller
Power-down Power-down Power-up,
PA off
Power-up,
PA on
(f
RF
= High)
Power-up,
PA off
(f
RF
= Low)
FSK
ENABLE
ASK
CLK
∆
T
XTO
> 250 µs
Power-down Power-down Power-up,
PA off
Power-up,
PA on
(High)
Power-up,
PA off
(Low)
FSK
ENABLE
ASK
CLK
∆
T
XTO
> 250 µs