Low-Capacitance VGA 2:2 Dual-Graphics Crossover Switch

The MAX14885E integrates high-bandwidth analog switches, level-translating buffers, and level-translating FET switches. The device implements a complete 2:2 dual-graphics crossover solution for VGA signal switching. The MAX14885E provides 12 very high-frequency 700MHz (typ) SPST switches for RGB signals, four low-frequency clamping switches for the display data channel (DDC) signals, two pairs of level-translating buffers for the HSYNC and VSYNC signals, and integrated extended ESD protection. The MAX14885E is used to select one of two sources to either of two destinations (see Typical Operating Circuit in the full data sheet) within a laptop computer.

Horizontal and vertical synchronization (SH/SV) inputs feature level-shifting buffers to support low-voltage controllers and standard 5V TTL-level monitors. DDC, consisting of SDA and SCL, are FET switches that protect the low-voltage VGA source from potential damage from high-voltage presence on the monitor while reducing capacitive load.

All 14 output terminals of the MAX14885E feature high-ESD protection to ±15kV Human Body Model (HBM) and ±6kV IEC 61000-4-2 Contact Discharge (see the Pin Description in the full data sheet). All other pins are protected to ±2kV HBM.

The MAX14885E is specified over the extended -40°C to +85°C temperature range, and is available in a 40-pin TQFN (5mm x 5mm) package.

Applications

* Notebook Computer—Switchable Graphics

* Low Quiescent Current ≤ 5µA (max)

* Low 5Ω (typ) On-Resistance (RGB Signals)

* High Bandwidth, 700MHz (typ), RGB

* DDC Level Shifting, Isolation with Internal Pullup Termination, and Protection

* Horizontal and Vertical Sync Level Shifting and Buffering

* Inputs Compatible with VL, Outputs TTL Compatible

* Source/Sink ±10mA on Each SH, SV Output

* Independent Selectable Logic Inputs for Switching

* High ESD Protection on Outputs

* ±15kV ESD HBM

* ±6kV IEC 61000-4-2 Contact Discharge

* Small, 40-Pin TQFN (5mm x 5mm) Package