le79r241 Zarlink Semiconductor, le79r241 Datasheet - Page 15

• Manufacturer Part Number: le79r241
• Description: Intelligent Subscriber Line Interface Circuit
• Manufacturer: Zarlink Semiconductor

Ringing Specifications
Current-Limit Behavior
Thermal Shutdown Fault Indications
Note:
1.
2.
3.
4.
5.
6.
7.
OPERATING MODES
The Le79R241 ISLIC device receives multiplexed control data on the P1, P2 and P3 pins. The LD pin then controls the loading
of P1, P2, and P3 values into the proper bits in the Le79R241 ISLIC device control register. When the LD pin is less than 0.3 V
below VREF (< (VREF – 0.3 V)), P1–P3 must contain data for relay control bits RD1, RD2 and RD3. These are latched into the
first three bits in the Le79R241 ISLIC device control register. When the LD pin is more than 0.3 V above VREF, P1–P3 must
contain Le79R241 ISLIC device control data C1, C2, and C3, which are latched into the last three bits of the Le79R241 ISLIC
device control register. Connecting the LD pin to VREF locks the contents of the Le79R241 ISLIC device control register.
The operating mode of the Le79R241 ISLIC device is determined by the C1, C2, and C3 bits in the control register of the
Le79R241 ISLIC device. Table 1 defines the Le79R241 ISLIC device operating modes set by these signals.
Under normal operating conditions, the Le79R241 ISLIC device does not have active relays. The Le79R241 ISLIC device to
VE790 series ISLAC device interface is designed to allow continuous real-time control of the relay drivers to avoid incorrect data
loads to the relay bit latches of the Le79R241 devices.
To perform external ringing, the VE790 series ISLAC device is set to external ringing mode (RMODE = 1), enables the ring relay,
and puts the Le79R241 ISLIC device in the Standby mode.
These tests are performed with the following load impedances:
Frequency < 12 kHz – Longitudinal impedance = 500 Ω; metallic impedance = 300 Ω
Frequency > 12 kHz – Longitudinal impedance = 90 Ω; metallic impedance = 135 Ω
Not tested or partially tested in production. This parameter is guaranteed by characterization or correlation to other tests.
This parameter is tested at 1 kHz in production. Performance at other frequencies is guaranteed by characterization.
When the Le79R241 ISLIC device and 790 series codec is in the anti-sat operating region, this parameter is degraded. The exact
degradation depends on system design.
–55 dBm gain tracking level not tested in production. This parameter is guaranteed by characterization and correlation to other tests.
This spec is valid from 0 V to VBL or –50 V, whichever is lower in magnitude.
Other ringing-voltage characteristics are set by the 790 series codec.
Peak Ringing Voltage
Disconnect
Tip Open
Standby
No Fault
Thermal Shutdown
Active Ringing
SLIC Mode
Item
Applied fault between ground and T/R
VBH applied to Tip or Ring
Ring Short to GND
Short Tip-to-VBH
Short Ring-to-GND
790 series codec generating internal ringing
Fault
Active Internal Ringing
Condition
Condition
Zarlink Semiconductor Inc.
15
Min
IMT operates normally (V
KG, IMT above 2.8 V; ILG operates normally
Min
20
24
26
VBH+6
Typ
VBH/200K
Typ
100
35
38
35
1
Indication
REF
Max
±1 V)
Max
100
46
47
44
Unit
V
Unit
mA
µA
A
Note
Note
7.
6.
2.