ATA5278 ATMEL Corporation, ATA5278 Datasheet - Page 6

• Manufacturer Part Number: ATA5278
• Description: Stand-alone Antenna Driver
• Manufacturer: ATMEL Corporation

3.4
6
Oscillator
ATA5278
In case the microcontroller is not able to communicate properly with the ATA5278 or any other
disturbance has occurred, it can trigger a reset (like a power-on-reset, POR) in the chip by pull-
ing the NRES pin to ground, which will bring the logic back to the startup state, i.e., all
configurations are at default and the IC is in power-down mode.
Figure 3-3.
The ATA5278 is equipped with an internal oscillator circuitry that provides the system clock sig-
nal needed for operation. It is intended to work with an externally applied passive reference
device such as a ceramic resonator or a crystal. Active clock sources like microcontrollers or
crystal oscillators, however, can also be used.
oscillator circuitry.
Figure 3-4.
Int. state
C
NRES
S_CS
OSC
in
External Reset
Internal Oscillator Circuitry
= 12 pF typ.
Pull-down
OSCI
f = 8 MHz
X
X
R
fb
= 250 k typ.
t
POR
NRES
S1
Figure 3-4
OSCO
C
R
out
d
shows the internal structure of the
= 420
Power-down
= 12 pF typ.
Clock signal
judging
Enable signal
from SPI
To internal
logic
4832D–RKE–12/07