Analog Devices Inc./Maxim Integrated DS21610QN

Overview

DS21610QN from Maxim Integrated is a multirate, low-jitter clock adapter IC that converts E-carrier (2.048MHz) and T-carrier (1.544MHz) clocks to multiple PDH rates, delivers two frequency-locked clock outputs (CLKOUT1/CLKOUT2), and provides an 8kHz frame-sync output (SYNCOUT) phase-alignable to SYNCIN. It operates from 3.3V or 5V supply, supports industrial temperature range (−40°C to +85°C), and targets telecom line-card timing in E1/T1 multiplexing systems.

For engineers reviewing the DS21610QN datasheet, DS21610QN pinout, DS21610QN application, or DS21610QN equivalent, key selection criteria include jitter performance (≤0.020 UI_P-P), dual-output synchronization capability, PLCC-28 package compatibility with legacy LXP610 designs, and support for both T-carrier/E-carrier mode selection via SEL pin.

Technical Context

The DS21610QN integrates an analog PLL with feedback divider and frame-sync generator to achieve precise frequency conversion between 1.544MHz and 2.048MHz carrier rates and their integer multiples (e.g., 6.144MHz, 8.192MHz). Its dual-clock architecture allows CLKOUT1 and CLKOUT2 to be independently configured via P1–P4 program pins under SEL control, while maintaining fixed phase alignment to SYNCIN within ≤50ms.

It features programmable SYNCOUT pulse width (long/short), selectable frame-sync polarity (FSP), and jitter transfer peaking in 4kHz–8kHz band (typical gain ≈1.4–1.6). The device requires no external components and maintains 8kHz output across all modes, supporting synchronous digital hierarchy (SDH/PDH) timing integrity in legacy telecom infrastructure.

Key Specifications

Pinout & Package

DS21610QN uses a 28-pin Plastic Leaded Chip Carrier (PLCC) package, compatible with standard surface-mount reflow profiles and socketed evaluation setups. Pin layout follows JEDEC MO-047A outline (56-G4001-001).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar clock rate adaptation applications.

Compared with LXP610SE and DS21610SN, the DS21610QN offers the unique combination of dual-output capability, 3.3V/5V flexibility, and industry-leading jitter performance in PLCC-28 - making it optimal for new E1/T1 timing designs requiring upgrade path and thermal robustness.

Availability

DS21610QN is available at Aetrix Electronics and suitable for telecom infrastructure, network access equipment, and industrial communications systems requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for DS21610QN 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 precision analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The DS21610QN belongs to Maxim's telecom timing portfolio, designed specifically to replace legacy clock adapters in E1/T1 infrastructure while meeting stringent jitter, phase-alignment, and environmental requirements of carrier-class equipment.

FAQ

What is the primary function of the DS21610QN in telecom timing systems?

The DS21610QN serves as a multirate clock adapter that converts between E-carrier (2.048MHz) and T-carrier (1.544MHz) clock rates while maintaining low jitter and phase alignment to frame-sync signals. In telecom timing systems, the DS21610QN generates two frequency-locked outputs (CLKOUT1 and CLKOUT2) plus an 8kHz SYNCOUT, enabling synchronized operation across E1/T1 line cards, multiplexers, and cross-connect equipment without external components.

Does the DS21610QN support both 3.3V and 5V supply voltages simultaneously?

No, the DS21610QN operates from a single supply rail-either 3.3V ±5% or 5V ±5%, selected at power-up. The device does not support dual-supply operation. Supply voltage must be stable within tolerance across the full −40°C to +85°C temperature range, and proper decoupling (e.g., 0.1µF ceramic near VDD pin) is required for reliable DS21610QN performance in high-speed clock applications.

How does the DS21610QN achieve phase alignment between CLKOUT1, CLKOUT2, and SYNCOUT?

The DS21610QN achieves phase alignment using internal frame-sync generation logic synchronized to either CLKIN or an external SYNCIN signal. When SYNCIN is asserted, the device locks all outputs-including CLKOUT1, CLKOUT2, and SYNCOUT-to the same frame boundary within ≤50ms. The DS21610QN's block diagram confirms this is implemented via feedback-controlled PLL and dedicated frame-sync generator circuitry, ensuring deterministic alignment regardless of input clock frequency.

Can the DS21610QN replace the LXP610SE without hardware changes?

Yes, the DS21610QN is pin-compatible with the LXP610SE in the 28-pin PLCC package and shares identical pin functions per Table 1-B (e.g., P1–P4, SEL, SYNCIN, CLKIN, CLKOUT1, CLKOUT2, SYNCOUT). No PCB modifications are needed for replacement. However, the DS21610QN adds 3.3V support and improved jitter performance, so firmware or configuration may require verification to ensure identical mode selection behavior in the DS21610QN.

What jitter specifications does the DS21610QN meet for CLKOUT1 at 1.544MHz?

At CLKOUT1 = 1.544MHz, the DS21610QN meets TR62411 jitter limits: maximum 0.020 UI_P-P (unfiltered), 0.010 UI_P-P (10Hz–40kHz band), and 0.012 UI_P-P (8kHz–40kHz band). These values are measured under standard conditions (VDD = 3.3V/5V, TA = −40°C to +85°C) and confirmed in Table 3-A of the DS21610QN datasheet-ensuring compliance with T1/E1 timing standards in deployed telecom gear.