ICL3224E_14 Datasheet, PDF (9/20 Pages) Intersil Corporation – +/-15kV ESD Protected, +3V to +5.5V, 1Microamp, 250kbps, RS-232 Transceivers with Enhanced Automatic Powerdown

ICL3224E, ICL3226E, ICL3244E
The ICL3244E inverting receivers disable during forced
(manual) powerdown, but not during automatic powerdown
(see Table 2). Conversely, the monitor receiver remains
active even during manual powerdown making it extremely
useful for Ring Indicator monitoring. Standard receivers
driving powered down peripherals must be disabled to
prevent current flow through the peripheral’s protection
diodes (see Figures 2 and 3). This renders them useless for
wake up functions, but the corresponding monitor receiver
can be dedicated to this task as shown in Figure 3.
TABLE 2. POWERDOWN LOGIC TRUTH TABLE
RCVR OR
XMTR
EDGE
WITHIN 30
SEC?
(NOTE 3)
FORCEOFF FORCEON TRANSMITTER RECEIVER R_OUTB
INPUT
INPUT
OUTPUTS OUTPUTS OUTPUTS
RS-232
LEVEL
PRESENT
AT
RECEIVER
INPUT?
INVALID
OUTPUT
MODE OF OPERATION
ICL3224E, ICL3226E
NO
H
H
Active
Active
N.A.
NO
L
Normal Operation (Enhanced
Auto Powerdown Disabled)
NO
H
H
Active
Active
N.A.
YES
H
YES
H
L
Active
Active
N.A.
NO
L
Normal Operation (Enhanced
Auto Powerdown Enabled)
YES
H
L
Active
Active
N.A.
YES
H
NO
H
L
High-Z
Active
N.A.
NO
L
Powerdown Due to Enhanced
Auto Powerdown Logic
NO
H
L
High-Z
Active
N.A.
YES
H
X
L
X
High-Z
Active
N.A.
NO
L
Manual Powerdown
X
L
X
High-Z
Active
N.A.
YES
H
ICL322XE - INVALID DRIVING FORCEON AND FORCEOFF (EMULATES AUTOMATIC POWERDOWN)
X
NOTE 4 NOTE 4
Active
Active
N.A.
YES
H
Normal Operation
X
NOTE 4 NOTE 4
High-Z
Active
N.A.
NO
L
Forced Auto Powerdown
ICL3244E
NO
H
H
Active
Active
Active
NO
L
Normal Operation (Enhanced
Auto Powerdown Disabled)
NO
H
H
Active
Active
Active
YES
H
YES
H
L
Active
Active
Active
NO
L
Normal Operation (Enhanced
Auto Powerdown Enabled)
YES
H
L
Active
Active
Active
YES
H
NO
H
L
High-Z
Active
Active
NO
L
Powerdown Due to Enhanced
Auto Powerdown Logic
NO
H
L
High-Z
Active
Active
YES
H
X
L
X
High-Z
High-Z
Active
NO
L
Manual Powerdown
X
L
X
High-Z
High-Z
Active
YES
H
ICL3244E - INVALID DRIVING FORCEON AND FORCEOFF (EMULATES AUTOMATIC POWERDOWN)
X
NOTE 4 NOTE 4
Active
Active
Active
YES
H
Normal Operation
X
NOTE 4 NOTE 4
High-Z
High-Z
Active
NO
L
Forced Auto Powerdown
NOTES:
3. Applies only to the ICL3244E.
4. Input is connected to INVALID Output.
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