ATA6621 ATMEL Corporation, ATA6621 Datasheet - Page 6

• Manufacturer Part Number: ATA6621
• Manufacturer: ATMEL Corporation

3.12
Figure 3-1.
3.12.1
3.12.2
6
Modes of Operation
ATA6621
Normal Mode
Silent Mode
a: V
b: V
c: Bus wake-up event
d: Wake-up from wake-up switch
VCC: 5V ±2%/50 mA
Modes of Operation
Communication: On
S
S
with undervoltage
> 5V
< 4V
Normal Mode
reset
b
This is the normal transmitting and receiving mode. The voltage regulator is in normal mode and
can source 50 mA. The undervoltage detection is activated. The watchdog needs a trigger signal
from PTRIG or NTRIG to avoid resets at NRES.
A falling edge at EN while TXD is high switches the IC into Silent Mode. The TXD signal has to
be logic high during the Mode Select window
independent outputs can be used, or two outputs from the same microcontroller port; in the sec-
ond case, the mode change is only one command. In Silent Mode, the transmission path is
disabled. Supply current from V
The overall supply current from V
I
VCCs
EN = 1
.
EN = 0
TXD = 1
EN = 0
EN = 0
TXD = 0
EN = 1
VCC: 5V/50 mA with undervoltage reset
Communication: OFF
Unpowered Mode, V
Go to silent command
Go to sleep command
Local wake-up event
Local wake-up event
Pre Normal Mode
b
Bat
Bat
is typically I
is the addition of 40 µA plus the V
Bat
a
= 0V
(Figure 3-2 on page
VSsi
c + d
= 40 µA with no load at the VCC regulator.
Communication: Off
VCC: switched off
Sleep Mode
b
with undervoltage reset
Communication: OFF
VCC: 5V ±7%/50 mA
c + d
7). For EN and TXD either two
Normal Mode
CC
regulator output current
b
4887B–AUTO–01/06