Texas Instruments ADS7841P

Overview

ADS7841P from Texas Instruments is a 12-bit, 4-channel sampling analog-to-digital converter (ADC) with synchronous serial interface, programmable 8-/12-bit resolution, ±1 LSB max INL/DNL, 200 kHz conversion rate at +5 V, and DIP-16 package. It operates from 2.7 V to 5 V, supports single-ended or differential inputs, and targets battery-powered data acquisition systems.

For engineers reviewing the ADS7841P datasheet, ADS7841P pinout, ADS7841P application, or ADS7841P equivalent, key selection criteria include its 4-channel multiplexer architecture, shutdown mode (<15 µW), reference voltage flexibility (100 mV to VCC), and compatibility with low-cost isolation in remote sensing.

Technical Context

The ADS7841P implements a capacitive redistribution successive approximation register (SAR) ADC with integrated sample-and-hold, enabling true simultaneous sampling across four analog inputs via an internal multiplexer. Its conversion timing is clocked externally via DCLK, supporting 15–24 clock cycles per conversion depending on resolution and power mode.

Digital control is delivered through an 8-bit serial command byte (START, A2–A0, MODE, SGL/DIF, PD1/PD0), with configurable channel selection, input mode (single-ended/differential), and power-down behavior. The MODE pin overrides the MODE bit to force 12-bit operation when held low.

Key Specifications

Pinout & Package

DIP-16 package (Ordering Code N, Package Drawing 180); 0.3-inch wide dual in-line format compatible with through-hole prototyping and industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog-to-digital conversion applications.

Compared with MAX1247BCPP+, ADS7841P offers hardware-selectable resolution and lower power in shutdown; versus ADS7842P, it trades internal reference convenience for wider VREF flexibility (100 mV–VCC) and broader input range adaptability.

Availability

ADS7841P is available at Aetrix Electronics and suitable for portable data loggers, handheld test instruments, and industrial sensor interfaces requiring stable component supply and long-term manufacturability.

Supply support for ADS7841P 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 high-reliability components for industrial, automotive, and communications markets.

The ADS7841P belongs to TI's precision data acquisition portfolio, designed specifically for low-power, multi-channel measurement in portable and distributed sensing systems.

FAQ

What is the maximum conversion rate of the ADS7841P at 2.7 V supply?

The ADS7841P achieves up to 125 kHz conversion rate at +2.7 V supply, VREF = +2.5 V, and fCLK = 2 MHz. This is specified over the full –40°C to +85°C operating range and reflects reduced clock speed tolerance at lower supply voltages. At +5 V, the ADS7841P supports 200 kHz - confirming its scalable performance across battery voltage droop conditions.

Does the ADS7841P require an external reference voltage?

Yes, the ADS7841P requires an external reference voltage applied to the VREF pin. It accepts any stable voltage from 100 mV to +VCC, directly setting the full-scale input range (e.g., 0–VREF for single-ended). Unlike the pin-compatible ADS7842P, the ADS7841P has no internal reference, giving designers full flexibility to match sensor output ranges.

How does the MODE pin affect resolution configuration in the ADS7841P?

The MODE pin on the ADS7841P provides hardware-level resolution control: when LOW, it forces all conversions to 12-bit regardless of the MODE bit in the control byte; when HIGH, the MODE bit determines whether each conversion is 8-bit (HIGH) or 12-bit (LOW). This dual-control scheme enables robust firmware-independent resolution locking in safety-critical applications.

Can the ADS7841P perform differential measurements between arbitrary channel pairs?

No - the ADS7841P supports only predefined differential configurations: CH0–CH1 and CH2–CH3, as defined by the SGL/DIF and A2–A0 bits per Tables I and II in the datasheet. It does not support cross-pair differential inputs (e.g., CH0–CH2). For such flexibility, a separate instrumentation amplifier or higher-channel-count ADC like the ADS8684 would be required.

What is the purpose of the COM pin on the ADS7841P?

On the ADS7841P, the COM pin serves as the analog ground reference for single-ended input mode. When SGL/DIF = HIGH, the selected channel (CH0–CH3) is measured relative to COM - which must be tied to a stable low-impedance ground or bias point. In differential mode, COM is unused. Proper COM decoupling is essential to maintain offset error < ±3 LSB across temperature.