Analog Devices Inc./Maxim Integrated MAX4885ETJ+TG075

Overview

MAX4885ETJ+TG075 from Maxim Integrated is a complete VGA 1:2 or 2:1 analog multiplexer IC integrating RGB, HSYNC/VSYNC, and DDC signal switching with level translation, charge-pump–boosted RGB switches (5Ω typical R_ON), ±8kV HBM ESD protection on signal pins, and 5µA shutdown current. It enables dual-port VGA routing in notebook docking stations and KVM switches.

For engineers reviewing the MAX4885ETJ+TG075 datasheet, MAX4885ETJ+TG075 pinout, MAX4885ETJ+TG075 application, or MAX4885ETJ+TG075 equivalent, key selection criteria include RGB switch R_ON/C_ON, DDC voltage clamping control via VCL, mode-select logic (M/SEL/EN), bidirectional HV signaling capability in 2:1 mode, and TQFN-32 thermal performance under extended temperature operation.

Technical Context

The MAX4885ETJ+TG075 implements three independent SPDT RGB analog switches with internal charge-pump–driven gate bias (QP-controlled), achieving 5Ω typical on-resistance and 13pF typical on-capacitance at +5V supply. Its HV path supports both buffered (1:2 mode, M = 0) and direct-pass (2:1 mode, M = 1) configurations for HSYNC/VSYNC, enabling TTL-level compatibility from low-voltage controllers or bidirectional signaling.

DDC switching uses programmable voltage clamping referenced to VCL (2.7V to V+), allowing +3.3V clamping for I²C-compliant signals or disabling clamping by tying VCL to V+. All signal paths feature break-before-make switching, ±8kV HBM ESD protection, and operation across –40°C to +85°C in a 5mm × 5mm TQFN package with exposed ground paddle.

Key Specifications

Pinout & Package

MAX4885ETJ+TG075 is housed in a 32-pin, 5mm × 5mm thin quad flat no-lead (TQFN-EP) package with exposed paddle thermally and electrically connected to GND. Pin 1 is located at top-left per standard orientation; exposed pad (EP) must be soldered to a solid ground plane for optimal thermal performance and ESD robustness.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar VGA multiplexer applications.

Compared with MAX4885ETJ+TG075, MAX4886ETJ+ sacrifices charge-pump–enhanced analog performance and +5V flexibility for lower supply voltage operation, while TS3V330RGTR requires external components to achieve even basic VGA multiplexing-making MAX4885ETJ+TG075 the only integrated solution supporting full 1:2/2:1 VGA with DDC clamping, HV buffering, and ESD-hardened signal paths.

Availability

MAX4885ETJ+TG075 is available at Aetrix Electronics and suitable for notebook docking stations, digital projectors, computer monitors, and KVM switches requiring stable component supply across industrial temperature ranges and long product lifecycles.

Supply support for MAX4885ETJ+TG075 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, computing, and communications applications.

The MAX4885ETJ+TG075 belongs to Maxim's Graphics Interface product line, designed specifically to simplify VGA signal routing in space-constrained, multi-port systems while maintaining signal fidelity, ESD robustness, and power efficiency.

FAQ

What is the function of the QP pin on the MAX4885ETJ+TG075?

The QP pin on the MAX4885ETJ+TG075 is the charge-pump enable input, active low. When QP is driven low, the internal charge pump operates to generate a boosted gate-drive voltage for the RGB analog switches, achieving 5Ω typical on-resistance. Driving QP high disables the charge pump, reducing noise but increasing R_ON to 6–10Ω. This trade-off allows designers to optimize between analog performance and noise sensitivity in their VGA signal path.

How does the MAX4885ETJ+TG075 handle DDC signal level translation?

The MAX4885ETJ+TG075 handles DDC level translation via the VCL pin, which sets the clamp voltage for open-drain DDCA_ and DDCB_ outputs. When VCL is set to +3.3V, DDC signals are clamped to approximately +2.6V (one diode drop below VCL), ensuring compatibility with VESA-standard I²C devices. If clamping is not needed-for example, when interfacing with +5V-tolerant ASICs-VCL may be tied directly to V+, disabling the clamp function entirely.

Can the MAX4885ETJ+TG075 operate in both 1:2 and 2:1 VGA multiplexer modes simultaneously?

No, the MAX4885ETJ+TG075 cannot operate in both 1:2 and 2:1 modes simultaneously. Mode selection is controlled by the M pin: M = 0 configures the device for 1:2 operation with buffered HSYNC/VSYNC outputs, while M = 1 selects 2:1 operation with unbuffered, bidirectional HV signaling. The M pin must be held static during operation; dynamic reconfiguration is possible but requires coordinated control of M, SEL, and EN to avoid signal contention or undefined states.

What is the maximum operating frequency supported by the RGB switches in the MAX4885ETJ+TG075?

The RGB switches in the MAX4885ETJ+TG075 support a maximum small-signal bandwidth of 350MHz (typical) when the charge pump is enabled (QP = GND). This bandwidth is verified under 50Ω source/load conditions and ensures faithful reproduction of high-resolution VGA timing signals, including UXGA (1600×1200) at 60Hz. Bandwidth remains usable above 300MHz even with charge pump disabled, though insertion loss increases slightly.

Does the MAX4885ETJ+TG075 require external capacitors for its charge pump?

No, the MAX4885ETJ+TG075 does not require external capacitors for its charge pump. The device integrates all necessary capacitors internally, enabling fully self-contained boosted gate-drive generation for the RGB switches. Only standard 0.1µF ceramic decoupling capacitors on each V+ pin and on VCL are required-no additional charge-pump timing or storage capacitors are needed, simplifying PCB layout and reducing bill-of-materials count.