TLK1221 Datasheet, PDF (2/23 Pages) Texas Instruments – ETHERNET TRANSCEIVER

TLK1221
SLLS713 – FEBRUARY 2007
www.ti.com
The TLK1221 is housed in a high-performance, thermally enhanced, 40-pin QFN package. Use of this package
does not require any special considerations except to note that the pad, which is an exposed die pad on the
bottom of the device, is a metallic thermal and electrical conductor. It is required that the TLK1221 pad be
soldered to the thermal land on the board as it serves as the main ground connection for the device.
The TLK1221 is characterized for operation from –40°C to 85°C.
This device uses a 2.5-V supply. The I/O section is 3.3-V compatible. With the 2.5-V supply, the chipset is very
power-efficient, dissipating less than 200 mW typical power when operating at 1.25 Gbps.
The TLK1221 is designed to be hot-plug capable. A power-on reset causes RBC0, RBC1, the parallel output
signal terminals, TXP, and TXN to be held in the high-impedance state.
Differences Between TLK2201B, TLK2201BI, TLK1221, and TNETE2201
The TLK1221 is the functional equivalent of the TNETE2201. There are several differences between the devices
as noted below. Refer to Figure 12 in the application information section for an example of a typical application
circuit.
• V_CC is 2.5 V for the TLK2201B, TLK2201BI, TLK1221, and TLK1201A vs 3.3 V for TNETE2201.
• The PLL filter capacitors on pins 16, 17, 48, and 49 of the TNETE2201 are no longer required. The
TLK2201B, TLK2201BI, TLK1221, and TLK1201A use these pins to provide added test capabilities. The
capacitors, if present, do not affect the operation of the device.
• No pulldown resistors are required on the TXP/TXN outputs.
• The TLK1221 is a QFN version of the TLK2201B optimized for GBE-only TBI-mode operation with no JTAG
functionality.
Functional Block Diagram
PRBSEN
LOOPEN
PRBS
Generator
TD(0–9)
10 Bit
Registers
2:1
MUX
Parallel to
Serial
Clock
TXP
TXN
REFCLK
Phase Generator
ENABLE
RBC1
RBC0
SYNC/PASS
Control
Logic
PRBS
Verification
Interpolator
and
Clock Extraction
Clock
2:1
MUX
Clock
RD(0–9)
SYNCEN
RBCMODE
Serial to Parallel
and
Comma Detect
2:1
MUX
Data
RXP
RXN
2
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