Analog Devices Inc./Maxim Integrated MAX9250GCM+

Overview

MAX9250GCM+ from Maxim Integrated is a 27-bit DC-balanced LVDS deserializer IC for automotive and industrial video interfaces, converting serial LVDS input (5–35MHz) into 18-bit RGB video data and 9-bit control data with programmable latch edge, output enable, and ±2% reference clock tolerance. It operates from +3.3V core supply and supports 1.8V–3.3V logic-level outputs, targeting in-vehicle displays and camera links.

For engineers reviewing the MAX9250GCM+ datasheet, MAX9250GCM+ pinout, MAX9250GCM+ application, or MAX9250GCM+ equivalent, key selection criteria include its 35MHz max parallel clock frequency, output enable (OUTEN) for busing, -40°C to +105°C operation, and compatibility with MAX9247 serializer in AC-coupled LVDS video systems.

Technical Context

The MAX9250GCM+ implements a PLL-based clock recovery architecture synchronized to REFCLK before locking to the incoming LVDS stream, with lock indication via LOCK output. Its deserialization separates video (RGB_OUT[17:0]) and control (CNTL_OUT[8:0]) phases using DE_OUT signaling, enabling timing-efficient blanking-period data transfer.

It features proprietary DC-balanced encoding/decoding for AC-coupling support, staggered RGB output switching across three 6-bit groups to reduce EMI, and output transition time scaling per RNG[1:0] settings-enabling optimized signal integrity across 5–35MHz operating range without external termination tuning.

Key Specifications

Pinout & Package

MAX9250GCM+ is housed in a 48-lead LQFP package (7mm × 7mm, 0.5mm pitch) with exposed thermal pad. Pin functions are electrically and physically distinct from MAX9248; OUTEN replaces SS functionality.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LVDS deserializer applications.

Compared with MAX9250ECM+, the MAX9250GCM+ trades 7MHz bandwidth for automotive-grade temperature margin and cost efficiency; versus MAX9248GCM+, it swaps spread-spectrum for output enable-making it the only choice for bused display backplanes in extended-temperature environments.

Availability

MAX9250GCM+ is available at Aetrix Electronics and suitable for navigation system displays, in-vehicle entertainment systems, and automotive video cameras requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX9250GCM+ 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, designs high-performance analog and mixed-signal ICs for automotive, industrial, and communications markets, with emphasis on signal integrity and power efficiency.

The MAX92xx deserializer family targets high-speed, noise-immune digital video transmission in space-constrained automotive and industrial systems, specifically addressing EMI, ground shift, and thermal reliability challenges in LVDS-based display links.

FAQ

What is the maximum parallel clock frequency supported by the MAX9250GCM+?

The MAX9250GCM+ supports a maximum parallel clock frequency of 35MHz, as specified in its AC Electrical Characteristics table. This limit distinguishes it from the MAX9250ECM+ variant (42MHz). The 35MHz rating applies across the full -40°C to +105°C operating range and is validated with worst-case process, voltage, and temperature corners. Exceeding this frequency may result in failed lock, increased bit-error rate, or invalid LOCK assertion.

How does the OUTEN pin function on the MAX9250GCM+?

The OUTEN pin on the MAX9250GCM+ is an active-high LVTTL/LVCMOS input that enables or disables all single-ended outputs (RGB_OUT[17:0], CNTL_OUT[8:0], DE_OUT, PCLK_OUT) except LOCK. When OUTEN is low, those outputs enter high-impedance state - allowing multiple MAX9250GCM+ devices to share a common bus. The datasheet specifies 10–30ns enable/disable timing, requiring ≥30ns dead time between disabling one device and enabling another to prevent contention.

Can the MAX9250GCM+ be used with the MAX9247 serializer?

Yes, the MAX9250GCM+ is explicitly designed to pair with the MAX9247 serializer as a complete digital video transmission system. The MAX9250GCM+ recovers clock and data from the MAX9247's LVDS output, supports its DC-balanced encoding, and synchronizes automatically without external control lines. The combination is validated for operation up to 35MHz parallel clock (840Mbps serial data rate) over CAT5 cable up to 10m with BER <10⁻¹².

What is the purpose of the R/F pin on the MAX9250GCM+?

The R/F pin on the MAX9250GCM+ selects whether RGB_OUT[17:0] and CNTL_OUT[8:0] are latched on the rising edge (R/F = high) or falling edge (R/F = low) of PCLK_OUT. This setting directly controls timing alignment with downstream devices such as display controllers or FPGAs. The latch edge polarity need not match the MAX9247 serializer's input latch edge - providing independent optimization of transmit and receive timing margins.

Does the MAX9250GCM+ support AC-coupling on its LVDS inputs?

Yes, the MAX9250GCM+ supports AC-coupling on IN+/IN- via internal 42–88kΩ bias resistors to 1.2V, enabling capacitor-isolated LVDS links. This blocks ground potential differences and low-frequency noise between transmitter and receiver. For optimal performance, use 0.1µF ceramic capacitors per line at frequencies ≤18MHz; for 18–35MHz, refer to Figure 16 for calculated values (e.g., 33nF for two-capacitor-per-link at 35MHz). The device maintains DC balance to ensure reliable AC-coupled operation.