ATA8404/ATA8405 [DATASHEET]

9136G–AUTO–06/14

8

Figure 4-3. Timing FSK Mode with ENABLE Connected to the Microcontroller

4.2.2

ASK Mode

The Atmel ATA8404/ATA8405 is activated by ENABLE = High, FSK = High and ASK = Low. After activation the

microcontroller is switched to external clocking. After typically 0.6ms, the CLK driver is activated automatically (the

microcontroller waits until the XTO and CLK are ready). After another time period of

≤ 250µs, 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 Atmel ATA8404/ATA8405 is switched to power-down mode with

ENABLE = Low and FSK = Low.

Figure 4-4. Timing ASK Mode with ENABLE Connected to the Microcontroller

Power-down

Power-down

Power-up,

PA off

Power-up,

PA on

Power-up,

PA off

FSK

ENABLE

ASK

CLK

ΔT

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

ΔT

XTO

> 250 μs