Analog Devices Inc. LTC1099CN#PBF

Overview

LTC1099CN#PBF from Analog Devices (formerly Linear Technology) is a high-speed 8-bit analog-to-digital converter with integrated sample-and-hold, designed for microprocessor interfacing in real-time data acquisition systems. It delivers 2.5 µs conversion time in both RD and WR/RD modes, supports 2.5 V/µs input slew rate, operates from a single 5 V supply, and features latched three-state outputs with overflow flag - enabling direct connection to 8-bit data buses in industrial control and test instrumentation.

For engineers reviewing the LTC1099CN#PBF datasheet, LTC1099CN#PBF pinout, LTC1099CN#PBF application, or LTC1099CN#PBF equivalent, key selection considerations include its internal S/H acquisition time (240 ns), total unadjusted error (±1 LSB), TC-pin-adjustable conversion timing, stand-alone operation capability, and compatibility with common 8-bit microcontrollers such as TMS320C25.

Technical Context

The LTC1099CN#PBF implements a 2-step semi-flash ADC architecture using dual 4-bit flash converters and a shared switched-capacitor comparator, reducing comparator count from 255 (full flash) to 16 while maintaining monotonicity and no missing codes. Its internal sample-and-hold has 110 ns aperture time and 240 ns acquisition time, enabling accurate digitization of up to 156 kHz full-scale sine inputs.

Digital interface supports three operational modes: RD mode (conversion triggered by RD↓), WR/RD mode (WR↓ initiates conversion, RD↓ reads data), and Stand-Alone mode (CS/RD held low). All timing is edge-sensitive and internally generated - eliminating external clock or pulse-shaping requirements.

Key Specifications

Pinout & Package

Package: 20-lead 0.3" wide plastic DIP (N package), through-hole mount, JEDEC MS-001 compliant, operating temperature range 0°C to 70°C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit ADC applications.

Compared with LTC1099ACN#PBF, the LTC1099CN#PBF trades 0.25 LSB accuracy for lower cost in volume production, while MAX1112CPE+ replaces parallel bus simplicity with serial footprint savings - making LTC1099CN#PBF optimal for cost-sensitive, bus-connected industrial controllers requiring cascading.

Availability

LTC1099CN#PBF is available at Aetrix Electronics and suitable for industrial data acquisition, test equipment, embedded control systems, and analog signal processing applications requiring stable component supply, long-term manufacturability, and legacy part continuity.

Supply support for LTC1099CN#PBF 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

Analog Devices acquired Linear Technology in 2017 and maintains full support for legacy Linear ICs including the LTC1099 family. Linear was renowned for high-performance analog and mixed-signal ICs targeting precision measurement and power management.

The LTC1099 belongs to Linear's high-speed precision ADC product line, engineered specifically for microprocessor-based data acquisition where low-latency, single-supply operation, and integrated S/H reduce system complexity and improve reliability in harsh environments.

FAQ

What is the operating temperature range for the LTC1099CN#PBF?

The LTC1099CN#PBF is specified for commercial temperature operation from 0°C to 70°C. This range is defined by the "C" suffix in the part number and applies to all electrical and timing parameters unless otherwise noted in the datasheet. The device uses the N-package (20-lead PDIP), which has θJA = 130°C/W, allowing safe operation within this range under typical PCB thermal conditions.

Does the LTC1099CN#PBF require an external clock source?

No, the LTC1099CN#PBF does not require an external clock. All timing is generated internally and triggered by edge-sensitive digital inputs (RD or WR). This eliminates clock distribution challenges and reduces BOM count. The conversion time is factory-set to 2.5 µs and can be adjusted via the TC pin, but no external oscillator or clock signal is needed for basic operation.

How is the LTC1099CN#PBF interfaced to an 8-bit microcontroller data bus?

The LTC1099CN#PBF connects directly to an 8-bit microcontroller data bus using its latched three-state outputs (DB0–DB7). With CS and RD held low, outputs drive the bus; RD↑ places outputs in high-impedance state. The RDY signal (WR/RDY pin in RD mode) can be tied to the processor's READY input to automatically stretch read cycles until conversion completes - enabling zero-wait-state operation without software polling.

Can the LTC1099CN#PBF be used without a microprocessor?

Yes, the LTC1099CN#PBF supports Stand-Alone (SA) mode. By tying CS and RD low and applying WR pulses, it continuously performs conversions and updates outputs asynchronously. In this configuration, WR↓ starts each conversion, and new data appears on DB0–DB7 after 2.5 µs. No processor or timing logic is required - ideal for simple digitization tasks like LED bar-graph drivers or analog-to-digital front-ends in dedicated hardware.

What is the purpose of the OFL (overflow) pin on the LTC1099CN#PBF?

On the LTC1099CN#PBF, the OFL pin is an active-low output that asserts when the analog input voltage exceeds the reference voltage (VIN > VREF). This flag enables cascading multiple LTC1099CN#PBF devices to achieve higher resolution - for example, using the OFL signal from a primary converter to enable a secondary converter for the overflow range, effectively extending to 9-bit or more without external comparators or logic.