Analog Devices Inc./Maxim Integrated DS1099U-CD+

Overview

DS1099U-CD+ from Maxim Integrated is a factory-programmed, low-frequency dual-output silicon oscillator with independently enabled CMOS/TTL-compatible outputs (OUT0 and OUT1), delivering frequencies from 0.25Hz to 1.048MHz across a 2.7V–5.5V supply. It sinks up to 16mA per output for direct LED driving and operates from –40°C to +125°C. Used in flashing status indicators and power-supply timing.

For engineers reviewing the DS1099U-CD+ datasheet, DS1099U-CD+ pinout, DS1099U-CD+ application, or DS1099U-CD+ equivalent, key selection considerations include factory-set divider values (X0=21, X1=22), µSOP-8 package constraints, dual-output enable control logic (active-low OE0/OE1), and ±100ppm/°C temperature stability over industrial temperature range.

Technical Context

The DS1099U-CD+ integrates a fixed 1.048MHz master oscillator followed by two independent binary dividers (X0=21, X1=22), yielding nominal output frequencies of 1Hz (OUT0) and 0.5Hz (OUT1). Output drivers remain active even when disabled - forcing high state without halting internal oscillation or division.

Each output features active-low enable (OE0/OE1), CMOS/TTL-compatible voltage levels (VOH ≥2.4V at –1mA, VOL ≤0.4V at 12mA/16mA), and no external timing components required. Power-up time is ≤10ms, and frequency tolerance is ±1.0% at +25°C.

Key Specifications

Pinout & Package

DS1099U-CD+ is housed in an 8-pin µSOP package (2.0mm × 2.5mm, 0.5mm pitch), RoHS-compliant, with exposed pad grounded per Maxim's substrate connection specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1099U-AC+ and DS1099U-BD+, the DS1099U-CD+ provides the lowest available factory-set frequencies (1Hz/0.5Hz), maximizing LED visibility duration and minimizing average current draw - critical for energy-constrained or thermally sensitive applications.

Availability

DS1099U-CD+ is available at Aetrix Electronics and suitable for flashing LED status indicators, switch-mode power supplies, and consumer appliances requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for DS1099U-CD+ 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 precision analog, mixed-signal, and timing solutions for industrial, computing, and communications markets.

The DS1099U-CD+ belongs to the EconOscillator™ family - purpose-built for cost-sensitive, low-power, low-frequency timing applications where programmability, reliability, and minimal external components are essential.

FAQ

What is the factory-programmed output frequency of DS1099U-CD+?

The DS1099U-CD+ is factory-programmed with OUT0 = 1Hz and OUT1 = 0.5Hz, derived from the fixed 1.048MHz master oscillator using binary dividers X0=21 and X1=22. These values are permanently stored in on-chip EEPROM and cannot be modified in-circuit. The DS1099U-CD+ delivers these exact frequencies across its full operating temperature and supply voltage range, with ±1.0% initial tolerance at +25°C.

Can DS1099U-CD+ drive LEDs directly without current-limiting resistors?

DS1099U-CD+ can drive standard 2V–3.2V LEDs directly at reduced brightness in many cases due to its 16mA sink capability per output (at –40°C to +85°C) and 12mA rating at full –40°C to +125°C range. However, for consistent brightness, thermal safety, and lifetime reliability, a series current-limiting resistor is recommended - especially when VCC exceeds 3.3V or ambient temperature approaches +125°C. The DS1099U-CD+ does not include internal current regulation.

How do OE0 and OE1 control the outputs of DS1099U-CD+?

OE0 and OE1 are active-low enable inputs: pulling OE0 low enables OUT0 (1Hz), while pulling it high forces OUT0 high-impedance (logic high). Similarly, OE1 controls OUT1 (0.5Hz). Both outputs remain fully functional when their respective OE pin is low; disabling one output has no effect on the other or on internal oscillator/divider operation. The DS1099U-CD+ continues consuming standby current (145–275µA) even when both outputs are disabled.

Is DS1099U-CD+ suitable for automotive applications?

DS1099U-CD+ is specified for –40°C to +125°C operation and meets industrial reliability standards, but it is not AEC-Q200 qualified and lacks automotive-specific screening or documentation. While it may function in under-hood or infotainment peripheral roles, Maxim's datasheet explicitly removed automotive references in Revision 2 (May 2015). For automotive use, DS1099U-CD+ requires full system-level qualification - it is not pre-qualified as an automotive-grade component.

What decoupling is required for stable operation of DS1099U-CD+?

DS1099U-CD+ requires high-quality ceramic decoupling capacitors placed as close as possible to the VCC and GND pins: a 0.1µF capacitor for bulk filtering and a 0.01µF capacitor for high-frequency noise suppression. Lead inductance must be minimized - surface-mount ceramics mounted directly adjacent to pins 3 (VCC) and 4 (GND) are mandatory. Failure to implement proper decoupling risks output jitter, increased supply current, or erratic enable behavior, particularly during output transitions.