am79231 ETC-unknow, am79231 Datasheet - Page 21

• Manufacturer Part Number: am79231
• Description: Intelligent Subscriber Line Interface Circuit Islic
• Manufacturer: ETC-unknow

Thermal-Management Equations (All Modes except Standby)
TIMING SPECIFICATIONS
Notes:
1. The P1
2. After a power-on reset or hardware reset, the relay outputs from the Am79231 turn all relays off. An
3. When writing to the ISLIC registers, the sequence is:
4. Am79231 registers are refreshed at 5.33 kHz when used with an ISLAC device.
5. If the clock or MPI becomes disabled, the LD pins and P1
6. Not tested in production. Guaranteed by characterization.
I
P
P
I
P
P
trSLD
tfSLD
tSLDPW
tSDXSU
tSDXHD
tSDXD
L
L
SLIC
TMG
SLIC
TMG
unassuming state is to place the relay control pins, which are level triggered, to a reset state for all relays.
Any noise encountered only raises the levels toward the register lock state.
a. Set LD pin to mid-state
b. Place appropriate data on the P1
c. Assert the LD pin to High or Low to write the proper data
d. Return LD pin to mid-state
and the line connection.
< 5 mA
> 5 mA
Symbol
Driver
R3
= (S
= 0
= (S
= (I
–
L
BAT
BAT
3 pins are updated continuously during operation by the LD signal.
– 5 mA)^2 • (R
– I
– I
LD
LD
LD
P1,P2,P3
P1,P2,P3
P1,P2,P3
LRL
L
(R
A logic 1 on the RD3 signal turns the R3 driver on and routes current from the R3 pin to
the RYE pin. In the option where the RYE pin is connected to ground, the R3 pin can sink
current from a relay connected to VCCD.
Another option is to connect the RYE pin to the B (Ring) lead through a diode and connect
a test load between R3 and the A (Tip) lead. This technique avoids the use of a relay to
connect a test load. However, it does not isolate the subscriber line from the linecard. The
test load must be connected to the Am79231 side of the protection resistor to avoid
damage to the R3 driver.
Signal
) • I
L
+ 2 • R
L
+ 0.3 W
TMG1
FUSE
Am79231 Data Sheet
+ R
Rise time Am79231 LD pin
Fall time Am79231 LD pin
LD minimum pulse width
P1–3 data Setup time
P1–3 data hold time
Max P1–3 data delay
))*I
TMG2
L
–
+ 0.3 W – P
3 pins
)
Parameter
TMG
Description
–
3 returns to 0 V state, thus protecting the Am79231
TMG resistor-current is limited to be 5 mA < I
If I
and it all flows in the Am79231.
These equations are valid when
R
because the longitudinal voltage is one-half the
battery voltage and the TMG switches require
approximately 2 V.
TMGX
L
< 5 mA, no current flows in the TMG resistor
• (I
Min
4.5
4.5
L
3
– 5 mA) < (S
Typ
BAT
– R
Max
L
2
2
5
I
L
)/2 – 2
Unit
µs
L
21
.