IDT82P2821BHG IDT, Integrated Device Technology Inc, IDT82P2821BHG Datasheet - Page 30

• Manufacturer Part Number: IDT82P2821BHG
• Description: IC LINE INTERFACE UNIT 640-PBGA
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of IDT82P2821BHG

• Function: Line Interface Unit (LIU)
• Interface: E1, J1, T1
• Number Of Circuits: 1
• Voltage - Supply: 1.8V, 3.3V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: *
• Includes: Defect and Alarm Detection, Driver Over-Current Detection and Protection, LLOS Detection, PRBSARB / IB Detection and Generation
• Number Of Transceivers: 1
• Screening Level: Industrial
• Mounting: Surface Mount
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Power (watts): -
• Lead Free Status / RoHS Status: Compliant, Lead free / RoHS Compliant
• Other names: 800-1703; 82P2821BHG

Table-2 Impedance Matching Value in Receive Differential Mode
all 22 receivers and the per-channel impedance matching configuration
bits - the R_TERM[2:0] bits (b2~0, RCF0,...) and the R120IN bit (b4,
RCF0,...) - are ignored.
channel basis. Three kinds of impedance matching are all supported
and selected by the R_TERM[2:0] bits (b2~0, RCF0,...) and the R120IN
bit (b4, RCF0,...). The R_TERM[2] bit (b2, RCF0,...) should be set to
match internal or external impedance. If the R_TERM[2] bit (b2,
RCF0,...) is ‘0’, internal impedance matching is enabled. The R120IN bit
(b4, RCF0,...) should be set to select Partially Internal Impedance
Matching or Fully Internal Impedance Matching. The internal program-
mable resistor (IM) is determined by the R_TERM[1:0] bits (b1~0,
Figure-8 Receive Differential Line Interface with Twist-
Note:
1. Partially Internal Impedance Matching and Fully Internal Impedance Matching are not supported when RIM is low.
2. Fully Internal Impedance Matching is not supported in transformer-less applications.
3. When RIM is low, the setting of the R_TERM[2:0] bits is ignored.
4. In transformer-less applications, the device should be protected against overvoltage. There are three important standards for overvoltage protection:
Functional Description
IDT82P2821
T1 100 Ω twisted pair (transformer-less
E1 120 Ω twisted pair (transformer-less)
T1 100 Ω twisted pair (with transformer)
E1 120 Ω twisted pair (with transformer)
J1 110 Ω twisted pair (with transformer)
J1 110 Ω twisted pair (transformer-less)
• UL1950 and FCC Part 68;
• Telcordia (Bellcore) GR-1089
• ITU-T K.20, K.21 and K.41
When RIM is low, only External Impedance Matching is supported for
When RIM is high, impedance matching is configured on a per-
E1 75 Ω coaxial (with transformer)
6.0 Vpp
Cable Condition
ed Pair Cable (with transformer)
1:1
RRINGn
Rr
RTIPn
4
)
Partially Internal Impedance Matching
R_TERM[2:0]
IM
000
001
010
000
001
010
011
(R120IN = 0)
1
120 Ω
Rr
21(+1) CHANNEL HIGH-DENSITY T1/E1/J1 LINE INTERFACE UNIT
30
RCF0,...). If the R_TERM[2] bit (b2, RCF0,...) is ‘1’, external impedance
matching is enabled. The configuration of the R120IN bit (b4, RCF0,...)
and the R_TERM[1:0] bits (b1~0, RCF0,...) is ignored.
without a transformer (transformer-less), while a coaxial cable must be
connected with a 1:1 transformer. Table 2 lists the recommended imped-
ance matching value in different applications. Figure-8 to Figure-10
show the connection for one channel.
reduced cost and board space. However, the waveform amplitude is not
standard compliant, and surge protection and common mode depres-
sion should be enhanced depending on equipment environment.
Figure-9 Receive Differential Line Interface with Coax-
A twisted pair cable can be connected with a 1:1 transformer or
The transformer-less connection will offer a termination option with
Fully Internal Impedance Matching
R_TERM[2:0]
4.74 Vpp
001
010
000
011
(R120IN = 1)
(not supported)
ial Cable (with transformer)
1, 2
1:1
(open)
Rr
RRINGn
Rr
RTIPn
R_TERM[2:0]
External Impedance Matching
1XX
IM
February 6, 2009
3
100 Ω
120 Ω
100 Ω
120 Ω
110 Ω
110 Ω
75 Ω
Rr