MAX9238EUM+

Serializers, Deserializers Overview

The MAX9238EUM+ is a hot-swappable, 21-bit, DC-balanced LVDS deserializer manufactured by Analog Devices Inc./Maxim Integrated. It operates within a -40°C to +85°C temperature range and utilizes a 48-lead TSSOP package. The device accepts three LVDS serial-data inputs and one parallel-rate LVDS clock input, deserializing them into 21 single-ended LVCMOS/LVTTL outputs. It supports an operating frequency range of 16MHz to 66MHz with a maximum throughput of 1.386Gbps. The main power supply (VCC) ranges from 3.0V to 3.6V, while the output supply (VCCO) allows logic levels from 1.8V to 5V. Worst-case supply current reaches 177mA at 66MHz.

Serializers, Deserializers Feature Summary

• Hot-swappable capability with on-the-fly frequency programming
• DC balance enabling AC-coupling for wider common-mode voltage range
• Falling-edge output strobe for data latching
• High-impedance outputs when PWRDWN is low, allowing output busing

Serializers, Deserializers Applications

• Automotive Navigation Systems
• Automotive DVD Entertainment Systems
• Digital Copiers
• Laser Printers

Serializers, Deserializers Procurement Notes

Verify that the ordering suffix 'T' is added if tape-and-reel packaging is required, as standard units are supplied in tubes. Confirm the specific lead-free/RoHS-compliant status indicated by the '+' suffix matches project requirements. Ensure compatibility with the companion serializer devices such as the MAX9209, MAX9211, MAX9213, or MAX9215 for proper system integration.

Serializers, Deserializers Selection Notes

Select the MAX9238EUM+ over the MAX9234 or MAX9236 when the application requires an operating frequency range between 16MHz and 66MHz. Choose this part specifically for its falling-edge output strobe characteristic. Ensure the design accommodates the separate VCC and VCCO power domains to support the desired output logic voltage levels ranging from 1.8V to 5V.

Serializers, Deserializers Part Context

This component belongs to the MAX9234/MAX9236/MAX9238 family of hot-swappable, 21-bit, DC-balanced LVDS deserializers. It serves as the receiver counterpart to serializers like the MAX9209 series. The MAX9238 variant is distinguished by its higher frequency operation up to 66MHz and its falling-edge output strobe, differentiating it from the rising-edge MAX9234 and lower-frequency MAX9236.

Serializers, Deserializers Replacement Considerations

The MAX9238EUM+ is functionally equivalent to the MAX9222 when operated in DC-balance mode. Pinouts are identical to the MAX9210/MAX9220/MAX9222 family, except pin 6 is No Connect (N.C.) on the MAX9238. Verify that the replacement maintains the required 16MHz to 66MHz frequency range and falling-edge strobe timing.

Serializers, Deserializers FAQ

How does the MAX9238 handle AC-coupling?

The MAX9238 features DC balance, which allows isolation between the serializer and deserializer using AC-coupling capacitors. This increases the receiver's common-mode voltage range and eliminates bit errors caused by ground potential variations.

What is the function of the PWRDWN pin?

Driving PWRDWN low places the outputs in a high-impedance state, stops the PLL, and reduces supply current to 50µA or less. Driving it high drives the outputs low until the PLL locks. It is 5V tolerant and internally pulled down to GND.

Can multiple MAX9238 outputs be bused?

Yes, the high-impedance outputs when PWRDWN is low allow output busing to form a 2:1 mux. A delay of at least 100ns must be observed between disabling one deserializer and enabling another to avoid contention.