JAJSI47B April 2017 – October 2019 LMH0397
PRODUCTION DATA.
If the LMH0397 is placed in CD Mode (EQ/CD_SEL = H), PCB trace equalization is enabled for IN0. While the LMH0397 is in CD Mode, SDI_IO EQ is powered down.
IN0 has an on-chip 100-Ω termination and is designed for AC coupling, requiring a 4.7-μF, AC-coupling capacitor for minimizing base-line wander. The PCB equalizer can compensate board trace insertion losses of –17 dB at data rates up to 2.97 Gbps. There are two adapt modes for IN0: AM0 manual mode and AM1 adaptive mode. In AM0 manual mode, fixed EQ boost settings are applied through user-programmable control. In AM1 adaptive mode, state machines automatically find the optimal EQ boost from a set of 16 predetermined settings defined in Registers 0x40-0x4F.
In CD Mode, the HOST_EQ0 pin determines the IN0 adapt mode and EQ boost level. For normal operation, HOST_EQ0 = F is recommended. HOST_EQ0 pin logic settings are shown in Table 5. These HOST_EQ0 pin settings can be overridden by register control. For more information, refer to the LMH0397 Programming Guide (SNLU225).
HOST_EQ0(1) | IN0± EQ BOOST(2) | RECOMMENDED INSERTION LOSS
BEFORE IN0±(3) |
---|---|---|
H | All Rates: AM0 Manual Mode, EQ=0x00 | < –4 dB |
F | Normal Operation
3G Rate: AM1 Adaptive Mode 1.5G, 270M Rates: AM0 Manual Mode, EQ= 0x00 |
0 to –17 dB |
R | All Rates: AM0 Manual Mode, EQ=0x80 | –8 dB |
L | All Rates: AM0 Manual Mode, EQ=0x90 | –10 dB |