Analog Devices Inc./Maxim Integrated DS1099U-PR+

Overview

DS1099U-PR+ from Maxim Integrated is a factory-programmed, low-frequency dual-output silicon oscillator with fixed 1.048MHz master clock and two independent binary dividers (X0/X1), delivering programmable square-wave outputs from 0.25Hz to 1.048MHz. It operates from 2.7V to 5.5V, sinks up to 16mA per output, and is rated for -40°C to +125°C - used in LED status indicators, printers, and switch-mode power supplies.

For engineers reviewing the DS1099U-PR+ datasheet, DS1099U-PR+ pinout, DS1099U-PR+ application, or DS1099U-PR+ equivalent, key selection criteria include factory-set divider values (α₀/α₁), independent OE-controlled output enable/disable, ±100ppm/°C temp drift, CMOS/TTL-compatible 16mA-sink capability, and µSOP-8 package compatibility with space-constrained industrial timing designs.

Technical Context

The DS1099U-PR+ integrates a fixed 1.048MHz master oscillator feeding two independent binary dividers (X0 and X1, each 0–22), enabling asynchronous, non-overlapping output frequencies. Divider settings are stored in factory-programmed EEPROM and cannot be modified in-circuit.

Each output (OUT0/OUT1) features dedicated enable inputs (OE0/OE1): logic-low enables sinking operation; logic-high forces output high without disabling internal oscillation or division. Outputs remain functional across full 2.7V–5.5V supply range and exhibit 45–55% duty cycle stability.

Key Specifications

Pinout & Package

DS1099U-PR+ is housed in an 8-pin µSOP package (2.0mm × 2.5mm, 0.5mm pitch), RoHS-compliant, with exposed pad thermally connected to GND. Pin 1 is OUT1; pins 7–8 are no-connect.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-frequency dual-output oscillator applications.

Compared with DS1086L-025+ and MAX7375AUB+, the DS1099U-PR+ uniquely delivers two factory-set, independently enabled square-wave outputs across seven decades of frequency - enabling hardware-decoupled timing in cost-sensitive, space-constrained industrial systems without MCU involvement.

Availability

DS1099U-PR+ is available at Aetrix Electronics and suitable for flashing LED status indicators, switch-mode power supplies, and printers requiring stable component supply with guaranteed long-term manufacturability and extended temperature support.

Supply support for DS1099U-PR+ 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 applications.

The DS1099U-PR+ belongs to Maxim's EconOscillator™ family - designed specifically for low-cost, low-power, factory-programmed timing in space- and firmware-constrained embedded systems where simplicity and reliability outweigh programmability.

FAQ

What is the factory-programmed frequency configuration of the DS1099U-PR+?

The DS1099U-PR+ has its divider settings α₀ and α₁ permanently programmed at the factory - indicated by the "U" and "R" suffixes per Maxim's ordering nomenclature. These correspond to specific binary exponent values (X0/X1) that set OUT0 and OUT1 frequencies within the 0.25Hz–1.048MHz range. The exact values are laser-marked on the package (a₀/a₁) and documented in the order-specific datasheet revision. DS1099U-PR+ cannot be reprogrammed in-system.

Can both outputs of the DS1099U-PR+ operate at different frequencies simultaneously?

Yes - the DS1099U-PR+ uses two independent binary dividers fed by a common 1.048MHz master oscillator, allowing OUT0 and OUT1 to run at entirely different frequencies (e.g., 1Hz and 100kHz) based on their respective factory-programmed divider exponents X0 and X1. This asynchronous dual-output capability is intrinsic to the DS1099U-PR+ architecture and requires no external coordination.

How does the DS1099U-PR+ behave when OE0 or OE1 is held high?

When OE0 or OE1 is high, the corresponding output (OUT0 or OUT1) is immediately forced high-impedance - but critically, the internal master oscillator and divider continue running. The output driver is disabled, not the timing core. This allows fast re-enablement without startup delay. DS1099U-PR+ does not enter a low-power shutdown mode; standby current remains ~145–275µA regardless of OE state.

Is the DS1099U-PR+ suitable for driving LEDs directly without current-limiting resistors?

The DS1099U-PR+ outputs can sink up to 16mA (at -40°C to +85°C) and 12mA (up to +125°C), making direct LED drive feasible - but a series resistor is still required to limit current to safe LED levels and prevent damage under worst-case VOL conditions. For example, with a 2.0V LED and 3.3V VCC, a minimum 82Ω resistor ensures ≤16mA. DS1099U-PR+ simplifies design but does not eliminate basic current limiting.

What is the power-up behavior of the DS1099U-PR+ and how long until outputs stabilize?

The DS1099U-PR+ requires ≤10ms after VCC reaches valid operating voltage (2.7V–5.5V) before outputs become active and stable. During this time, outputs remain in high-impedance or undefined state until internal oscillator lock and divider settling complete. OE pins must be asserted low *after* this 10ms window to guarantee deterministic output phase. DS1099U-PR+ does not guarantee initial output state - design must tolerate one uncertain half-cycle upon first enable.