Texas Instruments ADC0820BCWMX/NOPB

Overview

ADC0820BCWMX/NOPB from Texas Instruments is an 8-bit CMOS analog-to-digital converter with integrated track-and-hold, designed for high-speed µP interfacing in embedded data acquisition systems. It delivers 1.5 µs conversion time in WR-RD mode, ±½ LSB total unadjusted error (for BC-grade), 75 mW max power dissipation at 5 V, and operates ratiometrically with VREF(+) ≤ VCC. It is used in telecom front-ends and multi-channel sensor digitization where external sample-and-hold elimination is critical.

For engineers reviewing the ADC0820BCWMX/NOPB datasheet, ADC0820BCWMX/NOPB pinout, ADC0820BCWMX/NOPB application, or ADC0820BCWMX/NOPB equivalent, key selection criteria include its half-flash architecture enabling single-cycle sampling, TRI-STATE 8-bit parallel output timing, RD/WR dual interface modes, and 20-pin SOIC package compatibility with legacy industrial control boards.

Technical Context

The ADC0820BCWMX/NOPB implements a two-stage half-flash architecture: a 4-bit most-significant-bit (MSB) flash ADC drives an internal DAC that generates a reconstructed analog voltage; the residual difference is converted by a second 4-bit least-significant-bit (LSB) flash ADC. This structure achieves 8-bit resolution without successive approximation delay.

Its sampled-data comparators enable inherent sample-and-hold functionality - VIN is effectively captured at one instant during WR low (WR-RD mode) or RD falling edge (RD mode), supporting input slew rates up to 100 mV/µs without external hold circuitry. Interface logic supports both memory-mapped and I/O-port µP connections via CS, WR, RD, and MODE pins.

Key Specifications

Pinout & Package

ADC0820BCWMX/NOPB is packaged in a 20-pin Small Outline Integrated Circuit (SOIC) with 0.300-inch body width and standard JEDEC MS-013AC footprint. Pin 19 is NC; all logic signals meet MOS/TTL voltage thresholds.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADC0804LCN/NOPB, ADC0820BCWMX/NOPB delivers 66× faster conversion and eliminates external S/H; compared with MAX1112CPE+, it retains parallel throughput and overflow chaining but trades resolution and serial flexibility for deterministic µP timing and analog simplicity.

Availability

ADC0820BCWMX/NOPB is available at Aetrix Electronics and suitable for telecom signal digitization, industrial sensor hubs, and portable data loggers requiring stable component supply, long-lifecycle support, and SOIC-compatible footprint consistency.

Supply support for ADC0820BCWMX/NOPB 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with decades of precision data converter innovation.

The ADC0820-N product line was engineered for µP-centric data acquisition in cost-sensitive industrial and telecom equipment, prioritizing interface simplicity, self-contained sampling, and SOIC/PDIP package compatibility with legacy designs.

FAQ

What is the maximum analog input slew rate supported by ADC0820BCWMX/NOPB without external sample-and-hold?

The ADC0820BCWMX/NOPB supports analog input slew rates up to 100 mV/µs due to its inherent sampled-data comparator architecture, which captures VIN at one instant during WR low (WR-RD mode) or RD falling edge (RD mode). This eliminates need for external S/H in applications like 7 kHz sine wave digitization, as confirmed in the datasheet's Figure 34 and Inherent Sample-Hold section.

Does ADC0820BCWMX/NOPB require external clocking or timing components?

No, ADC0820BCWMX/NOPB requires no external clock. Its half-flash conversion is internally timed: WR-RD mode completes in ≤1.5 µs using internal 800 ns timeout (tI), and RD mode uses fixed 800 ns intervals per stage. All timing is derived from WR/RD edges - no crystal, oscillator, or RC network is needed.

How does the OFL pin on ADC0820BCWMX/NOPB enable extended resolution?

The OFL pin on ADC0820BCWMX/NOPB is an active-low overflow flag that goes low when VIN exceeds VREF(+). This signal can trigger a second ADC0820BCWMX/NOPB to digitize the overflow residue, enabling 9-bit resolution (e.g., MSB device + LSB device), as shown in datasheet Figure 30 - no external logic or glue required.

What are the logic voltage level requirements for CS, WR, and RD inputs on ADC0820BCWMX/NOPB?

CS, WR, and RD inputs on ADC0820BCWMX/NOPB accept MOS/TTL-compatible levels: logical "1" requires ≥2.0 V (min) at VCC = 4.75 V, and logical "0" requires ≤0.8 V (max). These thresholds ensure reliable operation with standard 5 V microcontrollers without level shifters, as specified in DC Electrical Characteristics Table.

Can ADC0820BCWMX/NOPB operate with a 3.3 V supply?

No, ADC0820BCWMX/NOPB is not rated for 3.3 V operation. Its absolute maximum VCC is 10 V, but minimum operating VCC is 4.5 V per Operating Ratings. At 3.3 V, logic thresholds and internal biasing fail - the device will not initialize or convert correctly. Use only 4.5 V to 8 V supplies, with 5 V being the nominal design point.