Analog Devices Inc./Maxim Integrated DS1099U-BC+T

Overview

DS1099U-BC+T from Maxim Integrated is a factory-programmed, low-power dual-output silicon oscillator generating independent square-wave outputs at 4Hz (OUT0) and 2Hz (OUT1), operating from 2.7V to 5.5V, sinking up to 16mA per output, and rated for -40°C to +125°C - used in LED status indicators and switch-mode power supply timing.

For engineers reviewing the DS1099U-BC+T datasheet, DS1099U-BC+T pinout, DS1099U-BC+T application, or DS1099U-BC+T equivalent, this page delivers verified electrical specs, validated µSOP-8 pin mapping, confirmed temperature-stable dual-frequency operation, and real-world design context for embedded timing replacement and LED-driving oscillator selection.

Technical Context

The DS1099U-BC+T integrates a fixed 1.048MHz master oscillator with two independent binary dividers (X0=18 → ÷262,144 = 4Hz; X1=19 → ÷524,288 = 2Hz), each controlled by dedicated OE pins. Outputs are asynchronous, CMOS/TTL-compatible, and remain active even when disabled (forced high).

It requires no external timing components, draws ≤275µA in standby, and maintains ±100ppm/°C frequency stability across its full industrial temperature range. The device's internal EEPROM stores divider settings, eliminating field programming needs.

Key Specifications

Pinout & Package

DS1099U-BC+T is housed in an 8-pin µSOP package (2.0mm × 2.5mm, 0.5mm pitch) 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+T (1Hz/0.5Hz) and DS1099U-DC+T (8Hz/4Hz), the DS1099U-BC+T offers a balanced mid-range timing pair ideal for general-purpose status signaling - avoiding excessive visual distraction while maintaining clear perceptibility across ambient lighting conditions.

Availability

DS1099U-BC+T is available at Aetrix Electronics and suitable for flashing LED status indicators, switch-mode power supplies, and consumer appliances requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for DS1099U-BC+T 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 power management ICs for industrial, computing, and communications markets.

The DS1099U-BC+T belongs to the EconOscillator™ family - engineered specifically to replace discrete timing circuits and microcontroller-based blink generators with factory-calibrated, ultra-low-power silicon oscillators for embedded status and control timing.

FAQ

What is the exact factory-programmed output frequency of DS1099U-BC+T?

The DS1099U-BC+T is factory-programmed with OUT0 = 4Hz and OUT1 = 2Hz, derived from the fixed 1.048MHz master oscillator divided by 2¹⁸ and 2¹⁹, respectively. These frequencies are permanently stored in on-chip EEPROM and cannot be reconfigured in-circuit. No external components or software are needed to achieve these outputs - the DS1099U-BC+T delivers them immediately upon power-up with OE0 and OE1 asserted low.

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

Yes - the DS1099U-BC+T outputs can sink up to 16mA per channel at VCC ≥ 2.7V and within -40°C to +85°C, enabling direct connection to standard 2V forward-voltage LEDs at 3.3V supply (e.g., ~11mA through LED). At 5V, a series resistor is recommended to limit current to ≤16mA. The DS1099U-BC+T's VOL remains ≤0.4V under full load, ensuring reliable low-state drive without external buffering.

What happens to the outputs when OE0 or OE1 is held high?

When OE0 or OE1 is high, the corresponding output (OUT0 or OUT1) is disabled and forced high-impedance - but critically, the DS1099U-BC+T documentation specifies that the output is "forced high", not high-impedance. This means the driver actively pulls the pin to VCC level, not floats it. The master oscillator and divider continue running regardless, so re-enabling the output results in immediate activity - though phase alignment with prior cycles is not guaranteed due to asynchronous reset behavior.

Is DS1099U-BC+T suitable for automotive applications?

The DS1099U-BC+T is rated for -40°C to +125°C operation and meets industrial reliability standards, but Maxim's datasheet explicitly removed automotive references in Revision 2 (May 2015) and does not specify AEC-Q200 qualification. While functionally capable in under-dash environments, DS1099U-BC+T is not certified for automotive use. For automotive-grade timing, consider AEC-Q200-qualified alternatives - the DS1099U-BC+T remains optimal for industrial servers, appliances, and power supplies where extended temperature range is required without formal automotive certification.

How does supply voltage variation affect DS1099U-BC+T output frequency?

Over 2.7V–5.5V, DS1099U-BC+T exhibits ±2.5% frequency variation - equivalent to ±25,000ppm - with worst-case drift of 3300ppm/V near mid-supply. This voltage sensitivity is inherent to its silicon oscillator topology. For applications demanding tighter regulation, maintain VCC within ±5% of nominal (e.g., 3.3V ±0.17V) or add a low-dropout regulator. Unlike crystal-based solutions, the DS1099U-BC+T trades absolute accuracy for integration, cost, and robustness - making it ideal where relative timing consistency matters more than ppm-level precision.