Complete VGA 1:2 or 2:1 Multiplexer

The MAX4885 integrates high-bandwidth analog switches and level translating buffers to implement a complete 1:2 or 2:1 multiplexer for VGA signals. The device provides switching for RGB, display data channel (DDC), and horizontal and vertical synchronization (HSYNC, VSYNC) signals. A low-noise charge pump with internal capacitors provides a boosted gate-drive voltage to improve performance of the RGB switches.

In the 1:2 multiplexer mode, HSYNC/VSYNC inputs feature level-shifting buffers to support low voltage CMOS or standard TTL-compatible graphics controllers. In the 2:1 multiplexer mode, the output buffers for the HSYNC/VSYNC inputs are disabled, allowing bidirectional signaling. In both modes, DDC signals are voltage-clamped to an external voltage to provide level translation and protection. The MAX4885 features a 5µA shutdown mode and is ESD protected to ±8kV human body model (HBM) on externally routed pins.

The MAX4885 is specified over the extended (-40°C to +85°C) temperature range, and is available in the 32-pin, 5mm x 5mm TQFN package.

Applications

* Notebook Computers * Servers

* +5V Single-Supply Operation

* Programmable Voltage Clamp for Open-Drain DDC Signals

* Low 5Ω (typ) On-Resistance (R, G, B Signals)

* Low 13pF (typ) On-Capacitance (R, G, B Signals)

* Break-Before-Make Switching Protects Against Circuit Shorts

* Low 300µA Supply Current (Lower than 1µA with Charge Pump Disabled)

* Space-Saving, Lead-Free 32-Pin (5mm x 5mm) TQFN Package