LTC1755 LINER [Linear Technology], LTC1755 Datasheet - Page 10

• Manufacturer Part Number: LTC1755
• Description: Smart Card Interface
• Manufacturer: LINER [Linear Technology]

APPLICATIONS
LTC1755
State Definitions
IDLE/DEACTIVATION
V
READY, ALARM, DATA, AUX2IN, AUX1IN = Z
CARD = PRES
Once the LTC1755 enters the Idle/Deactivation state the
deactivation sequence begins. The deactivation sequence
will continue until V
An activation command (PWR = 0V) will only be acknowl-
edged once this occurs.
10
CC
POWER OFF
, RST, CLK, I/O AUX2, AUX1 = L
Figure 4. LTC1755 State Diagram
PWR = DV
NC/NO
DEACTIVATION
DEACTIVATION
U
CC
ALARM
CC
IDLE
is discharged to approximately 1V.
INFORMATION
U
PRES NC/NO
PRES NC/NO
PWR = DV
FAULT > 5 s
PWR = 0V
W
or
CC
TIMEOUT
NO
FAULT
U
ACTIVE
FAULT
1755 F04
FAULT
ALARM/DEACTIVATION
Same as Idle/Deactivation except:
ALARM = L
The only possible next state is Idle/Deactivation which is
achieved by disabling the LTC1755 via the PWR pin
(i.e., PWR = DV
The alarm indication can be cleared by rapidly cycling the
PWR pin. However, a new activation cycle will not begin
until V
ACTIVE
V
RST = R
I/O, AUX2, AUX1, DATA, AUX2IN, AUX1IN = Ready for
data (after READY becomes low)
CARD = PRES
ALARM = H
FAULT TIMEOUT
Same as Active except:
The duration of a fault is being measured. If the fault
duration exceeds 5 s then the Alarm/Deactivation state
follows. If the fault duration is less than 5 s, then the
device is returned to the Active state.
CC
= 3V or 5V (as determined by the 5V/3V pin)
CC
IN
is or has dropped below approximately 1V.
, CLK = C
CC
NC/NO
).
IN