Data Sheet
February 2001
L7583A/B/C/D Line Card Access Switch
Application (continued)
Table 16. Truth Table for L7583A/B
INRING
INTESTin INTESTout
TSD
TESTin
Switches Switches
Break
Ring Test
Switches
Ring
TESTout
Switches Switches
0 V
0 V
0 V
5 V
5 V
0 V
5 V
5 V
0 V
0 V
5 V
0 V
5 V
5 V
0 V
5 V
0 V
5 V
0 V
0 V
0 V
5 V
5 V
5 V
5 V/Float1
5 V/Float1
5 V/Float1
5 V/Float1
5 V/Float1
5 V/Float1
5 V/Float1
5 V/Float1
0 V2
Off
Off
On
Off
Off
On
Off
Off
Off
On
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
On
Off
Off
Off
Off
Off
Off
Off
On
Off
Off
Off
Off
Off
Off3
On4
Off5
Off6
Off7
On8
Off9
Off9
Off9
Don’t
Care
Don’t
Care
Don’t
Care
1. If TSD = 5 V, the thermal shutdown mechanism is disabled. If TSD is floating, the thermal shutdown mechanism is active.
2. Forcing TSD to ground overrides the logic input pins and forces an all OFF state.
3. Idle/Talk state.
4. TESTout state.
5. TESTin state
6. Power ringing state.
7. Ringing generator test state.
8. Simultaneous TESTout and TESTin state.
9. All OFF state.
A parallel in/parallel out data latch is integrated into the L7583A/B. Operation of the data latch is controlled by the
logic level input pin LATCH. The data input to the latch is the INPUT pin of the L7583A/B, and the output of the data
latch is an internal node used for state control.
When the LATCH control pin is at logic 0, the data latch is transparent and data control signals flow directly from
INPUT, through the data latch to state control. Any changes in INPUT will be reflected in the state of the switches.
When the LATCH control pin is at logic 1, the data latch is active—the L7583A/B will no longer react to changes at
the INPUT control pin. The state of the switches is now latched; that is, the state of the switches will remain as they
were when the LATCH input transitioned from logic 0 to logic 1. The switches will not respond to changes in INPUT
as long as LATCH is held high.
Note that the TSD input is not tied to the data latch. TSD is not affected by the LATCH input. TSD input will override
state control via INPUT and LATCH.
16
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
