GS3140 Datasheet, PDF (16/40 Pages) Semtech Corporation – Multi-Rate Adaptive 3G SDI Equalizer

When Auto-SLEEP is selected, it is initiated by the assertion of LOS. Normal operation,
Manual-SLEEP, and Auto-SLEEP are controlled using the SLEEP bits in EQ_CONF_REG_0
accessed through the device‘s host interface.
4.8.3 Mute
The GS3140 features a MUTE function, in which the two halves of the output buffer are
driven statically to opposing levels. One will be set to the level of V_{CC_O} and the other
will be set to V_{CC_O} – swing amplitude (swing level set in the OUTPUT_SWING bits of
OUT_CONF_REG_0).
When Auto-MUTE is selected, it is initiated by the assertion of LOS. Manual-MUTE and
Auto-MUTE are controlled using the MUTE and AUTO_OUTPUT_MUTE bits in
OUT_CONF_REG_1 accessed through the device's host interface.
4.8.4 Sleep-Mute
By default, output drivers are powered down when the device is in SLEEP mode.
However, the GS3140 also features another power saving sleep mode in which the
output driver is muted (as described in Section 4.8.3) instead. All the other blocks are
configured similar to the description in Section 4.8.2. The purpose of this mode is to
output a noise-immune static signal while the chip is sleeping. Similar to SLEEP mode,
both manual and automatic features are available.
When MUTE_OUTPUT_IN_SLEEP bit in EQ_CONF_REG_2 is set to 1, the output drivers
will remain powered and enter MUTE whenever the device is in SLEEP.
4.8.5 Output Disable
The GS3140 features a mode of operation in which the output buffer is disabled to save
power, but all other parts of the chip remain active.
This mode of operation consumes more power than SLEEP mode, but less power than
normal operation. It facilitates faster return to normal operation than SLEEP mode when
required, because all internal stages of the EQ core are already active in this mode.
By default, if the device is not set to any other automatic power mode (Auto-SLEEP,
Auto-MUTE, Auto-SLEEP-MUTE), then the assertion of LOS will initiate OUTPUT DISABLE
mode. The output buffer will remain disabled until a signal is present.
If there is a signal present, the outputs may still be manually disabled by setting the
MANUAL_OUTPUT_DISABLE bit in OUT_CONF_REG_1 to 1, accessed through the
device’s host interface.
4.9 Serial Digital Output (DDO/DDO)
The output driver has a separate voltage supply (V_{CC_O}) which operates between 1.2V -
2.5V. The output buffer includes two on-chip 50Ω termination resistors.
GS3140
Final Data Sheet
PDS-060939
Rev.1
May 2015
www.semtech.com
16 of 40
Semtech
Proprietary & Confidential