LMH0034MA/NOPB National Semiconductor, LMH0034MA/NOPB Datasheet - Page 5

• Manufacturer Part Number: LMH0034MA/NOPB
• Description: IC HD/SD ADAPTIVE CBL EQUALIZER
• Manufacturer: National Semiconductor

Specifications of LMH0034MA/NOPB

• Applications: *
• Interface: *
• Voltage - Supply: *
• Package / Case: 16-SOIC (3.9mm Width)
• Mounting Type: Surface Mount
• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Operating Temperature (max): 85C
• Package Type: SOIC N
• Rad Hardened: No
• For Use With: SD034EVK - BOARD EVALUATION LMH0034
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *CLC034MA; *LMH0034MA; *LMH0034MA/NOPB; *LMH034MA; CLC034MA; CLC034MA; LMH0034MA

Block Diagram
Device Operation
BLOCK DESCRIPTION
The Equalizer Filter block is a multi-stage adaptive filter. If
Bypass is high, the equalizer filter is disabled.
The DC Restoration / Level Control block receives the dif-
ferential signals from the equalizer filter block. This block
incorporates a self-biasing DC restoration circuit to fully DC
restore the signals. If Bypass is high, this function is disabled.
The signals before and after the DC Restoration / Level Con-
trol block are used to generate the Automatic Equalization
Control (AEC) signal. This control signal sets the gain and
bandwidth of the equalizer filter. The loop response in the
AEC block is controlled by an external 1µF capacitor placed
across the AEC+ and AEC- pins. Cable Length Indicator
(CLI) is derived from this block.
The Carrier Detect / Mute block generates the carrier detect
signal and controls the mute function of the output. This block
utilizes the bi-directional CD/MUTE signal along with Mute
Reference (MUTE
The Output Driver produces SDO and SDO.
CABLE LENGTH INDICATOR (CLI)
The cable length indicator provides a voltage to indicate the
length of cable being equalized. The CLI voltage decreases
as the cable length increases.
MUTE REFERENCE (MUTE
The mute reference determines the amount of cable to equal-
ize before automatically muting the outputs. This is set by
applying a voltage inversely proportional to the length of cable
REF
).
REF
)
5
to equalize. As the applied MUTE
amount of cable that can be equalized before carrier detect is
de-asserted and the outputs are muted is decreased.
MUTE
before muting.
CARRIER DETECT / MUTE (CD/MUTE)
Carrier Detect / Mute is bi-directional, serving as both a carrier
detect (output function) and mute (input function).
When used as an output, CD/MUTE determines if a valid sig-
nal is present at the LMH0034 input. If MUTE
carrier detect threshold will be altered accordingly.
CD/MUTE provides a high voltage when no signal is present
at the LMH0034 input, and the outputs are automatically mut-
ed. CD/MUTE is low when a valid input signal has been
detected, and the outputs are automatically enabled.
As an input, CD/MUTE can be used to override the carrier
detect and manually mute or enable the LMH0034 outputs.
Applying a high input to CD/MUTE will mute the LMH0034
outputs. Applying a low input will force the outputs to be active
regardless of the length of cable or the state of MUTE
INPUT INTERFACING
The LMH0034 accepts either differential or single-ended in-
put. The input must be AC coupled. Transformer coupling is
not supported.
The LMH0034 correctly handles equalizer pathological sig-
nals for standard definition and high definition serial digital
video, as described in SMPTE RP 178 and RP 198, respec-
tively.
REF
may be left unconnected for maximum equalization
REF
voltage is increased, the
REF
www.national.com
20173402
is used, the
REF
.