Analog Devices Inc./Maxim Integrated DS21610SN

Overview

DS21610SN 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 carrier rates, delivers two frequency-locked clock outputs (CLKOUT1/CLKOUT2), provides an 8kHz frame-sync output, operates from 3.3V or 5V supply, and supports industrial temperature range (-40°C to +85°C) in 16-pin SO package for telecom timing systems.

For engineers reviewing the DS21610SN datasheet, DS21610SN pinout, DS21610SN application, or DS21610SN equivalent, this page delivers verified pin functions, jitter performance data (e.g., 0.005 UI_P-P typical in 10Hz–40kHz band), mode-select logic (P1–P4, SEL, FSP), phase-alignment capability with SYNCIN, and direct LXP610SE replacement context - all critical for synchronous digital hierarchy (SDH/SONET) interface design and carrier-grade clock distribution.

Technical Context

The DS21610SN implements dual PLL architecture: one analog PLL for clock synthesis and one digital feedback circuit for frame-sync generation. It accepts CLKIN at 1.544MHz or 2.048MHz and generates programmable CLKOUT1/CLKOUT2 outputs (e.g., 2.048/6.144MHz or 3.088/8.192MHz) with fixed integer ratios relative to CLKIN.

All outputs are frequency-locked to CLKIN; phase alignment to external SYNCIN (8kHz or subrates like 1–4kHz) is achieved within ≤50ms. The device uses four program pins (P1–P4) and mode select (SEL) to configure 32 distinct clock/sync combinations, with SYNCOUT pulse width selectable as "long" or "short" relative to CLKIN period.

Key Specifications

Pinout & Package

DS21610SN is housed in a 16-pin Small Outline (SO) package, 300-mil body width, RoHS-compliant, with standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LXP610SE and DS21610QN, the DS21610SN offers identical timing performance in a compact 16-pin SO package with added 3.3V support and RoHS compliance - making it the optimal choice for space-constrained, dual-voltage, and environmentally regulated telecom applications.

Availability

DS21610SN is available at Aetrix Electronics and suitable for E1/T1 line card timing, PDH multiplexer clocking, central office synchronization, and legacy network migration requiring stable component supply and long-term obsolescence management.

Supply support for DS21610SN 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 DS21610SN belongs to Maxim's telecom timing product line, engineered specifically for carrier-grade E1/T1 clock adaptation, frame-sync distribution, and PDH network synchronization with low jitter and industrial reliability.

FAQ

What is the supply voltage range supported by the DS21610SN?

The DS21610SN operates from either 3.3V ±5% or 5V ±5%, enabling seamless integration into both legacy 5V and modern low-voltage telecom line cards. This dual-supply capability eliminates the need for external level shifters or regulators when upgrading existing LXP610SE-based designs. The DS21610SN maintains full specification compliance across the entire temperature range (-40°C to +85°C) under both supply conditions.

Does the DS21610SN require external passive components for PLL operation?

No, the DS21610SN integrates all necessary PLL circuitry, dividers, and logic on-die and requires no external crystals, capacitors, or resistors for basic operation. Its self-contained architecture simplifies layout, reduces bill-of-materials cost, and improves reliability in vibration-prone telecom environments. The DS21610SN achieves this while delivering jitter performance compliant with ITU-T G.823 standards across its full operating range.

How does the DS21610SN achieve phase alignment between clock outputs and an external frame-sync signal?

The DS21610SN uses its SYNCIN pin to accept an external 8kHz or integer subrate (1kHz, 2kHz, 4kHz) frame-sync pulse, which locks the phase of CLKOUT1, CLKOUT2, and SYNCOUT to system boundaries within ≤50ms. This alignment is implemented via internal digital feedback circuitry that adjusts output edges relative to SYNCIN transitions. The DS21610SN maintains this lock even during CLKIN frequency variations within its ±10,000 ppm capture range.

Is the DS21610SN pin-compatible with the LXP610SE?

Yes, the DS21610SN is fully pin-compatible with the LXP610SE in the 16-pin SO package, including identical pin numbering, function mapping, and DC/AC timing behavior. This allows direct replacement on existing PCBs without layout changes. The DS21610SN extends compatibility by adding 3.3V operation and RoHS compliance while preserving all functional modes defined in the LXP610SE datasheet - ensuring backward compatibility for DS21610SN deployment.

What clock output combinations are supported by the DS21610SN when CLKIN = 1.544MHz?

When CLKIN = 1.544MHz, the DS21610SN supports multiple CLKOUT1/CLKOUT2 pairs including 2.048MHz/6.144MHz, 2.048MHz/8.192MHz, 2.560MHz/7.680MHz, and 4.096MHz/8.192MHz - all programmable via P1–P4 and SEL pins. Each combination is validated per Table 2-A of the datasheet and maintains <0.010 UI_P-P max jitter. The DS21610SN guarantees these outputs are frequency-locked to CLKIN and phase-alignable to SYNCIN in all configurations.