The MAX9390/MAX9391 dual 2 x 2 crosspoint switches perform high-speed, low-power, and low-noise signal distribution. The MAX9390/MAX9391 multiplex one of two differential input pairs to either or both low-voltage differential signaling (LVDS) outputs for each channel. Independent enable inputs turn on or turn off each differential output pair.Four LVCMOS/LVTTL logic inputs (two per channel) control the internal connections between inputs and outputs. This flexibility allows for the following configurations: 2 x 2 crosspoint switch, 2:1 mux, 1:2 splitter, or dual repeater. This makes the MAX9390/MAX9391 ideal for protection switching in fault-tolerant systems, loopback switching for diagnostics, fanout buffering for clock/data distribution, and signal regeneration.Fail-safe circuitry forces the outputs to a differential low condition for undriven inputs or when the common-mode voltage exceeds the specified range. The MAX9390 provides high-level input fail-safe detection for LVDS, HSTL, and other GND-referenced differential inputs. The MAX9391 provides low-level input fail-safe detection for LVPECL, CML, and other VCC-referenced differential inputs.Ultra-low 82ps(P-P)(max) pseudorandom bit sequence (PRBS) jitter ensures reliable communications in high-speed links that are highly sensitive to timing error, especially those incorporating clock-and-data recovery, or serializers and deserializers. The high-speed switching performance guarantees 1.5GHz operation and less than 65ps (max) skew between channels.LVDS inputs and outputs are compatible with the TIA/EIA-644 LVDS standard. The LVDS outputs drive 100Ω loads. The MAX9390/MAX9391 are offered in a 32-pin TQFP package and operate over the extended temperature range (-40°C to +85°C).Also refer to the MAX9392/MAX9393 with flow-through pinout.ApplicationsCentral Office Backplane Clock DistributionDSLAMFault-Tolerant SystemsHigh-Speed Telecom/Datacom EquipmentProtection Switching