Texas Instruments ADS7818PG4

Overview

ADS7818PG4 from Texas Instruments (formerly Burr-Brown) is a 12-bit successive approximation register (SAR) analog-to-digital converter with integrated sample/hold, internal 2.5V bandgap reference, and synchronous serial interface. It delivers 500kHz throughput at 11mW typical power dissipation, supports differential input with 0–5V unipolar span, and operates over –40°C to +85°C in MSOP-8 package. It serves as a high-speed, low-power front-end ADC in portable data acquisition systems.

For engineers reviewing the ADS7818PG4 datasheet, ADS7818PG4 pinout, ADS7818PG4 application, or ADS7818PG4 equivalent, key selection considerations include its guaranteed no-missing-codes performance, ±1 LSB integral linearity (EB grade), 72dB SNR at 100kHz, 1.625µs conversion time, and support for both MSB-first and LSB-first serial output modes via CONV control.

Technical Context

The ADS7818PG4 implements a capacitive redistribution SAR architecture fabricated in 0.6µm CMOS, enabling inherent sample/hold functionality without external components. Its internal 2.5V reference sets a 0–5V input range, and the VREF pin accepts external references from 2.0V to 2.55V for adjustable full-scale spans.

Conversion is initiated asynchronously by the CONV signal, independent of CLK timing, allowing flexible interfacing with DSPs or microcontrollers. The serial interface uses a single DATA line synchronized to CLK, with configurable MSB-first or LSB-first output determined by CONV state during the 13th clock cycle - eliminating need for additional control lines.

Key Specifications

Pinout & Package

ADS7818PG4 is packaged in an 8-pin MSOP (Mini Small Outline Package) with 0.65mm pitch, optimized for space-constrained PCB layouts while maintaining thermal and electrical performance. Pin assignments are identical to the ADS7818E/EB variants and validated per TI's official package drawing 337.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed, low-power SAR ADC applications.

Compared with ADS7818PG4, ADS7816EB trades 2 bits of resolution and full-temperature linearity for lower cost and identical footprint, while ADS8320EB prioritizes precision over speed and integration - making ADS7818PG4 the optimal balance of throughput, power, on-chip reference, and guaranteed performance across industrial temperature range.

Availability

ADS7818PG4 is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered data loggers, and DSP-based signal acquisition systems requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.

Supply support for ADS7818PG4 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 acquired Burr-Brown in 2000 and maintains full technical and manufacturing continuity for legacy precision analog products. TI is a global leader in analog and embedded processing, with decades of expertise in high-performance data converters.

The ADS7818PG4 belongs to TI's precision SAR ADC portfolio designed for applications demanding high speed, low power, and integrated reference stability - particularly in portable, industrial, and test equipment where board space and power budget are critical constraints.

FAQ

What is the guaranteed integral linearity error for ADS7818PG4 over temperature?

The ADS7818PG4 (EB grade) guarantees ±1 LSB integral linearity error over the full –40°C to +85°C operating temperature range, as specified in the official TI datasheet PDS-1408B. This is distinct from the P/PB grade (±2 LSB), and applies specifically to the ADS7818EB variant - which ADS7818PG4 matches in performance and marking. The guarantee covers all 4096 codes with no missing codes.

Can ADS7818PG4 operate with an external reference voltage, and what is the valid range?

Yes, ADS7818PG4 supports external reference voltages applied to the VREF pin within 2.0V to 2.55V. This overdrives the internal 2.5V bandgap reference via a 10kΩ series resistor (±30% tolerance). The resulting analog input range becomes 4.0V to 5.1V (2× reference), enabling precise full-scale matching - for example, a 2.048V reference yields exactly 0–4.095V input range (1mV/LSB).

How does the power-down mode function in ADS7818PG4, and what is the wake-up time?

ADS7818PG4 enters power-down mode when CONV remains LOW during conversion and stays LOW at the start of the 13th clock cycle. Power dissipation drops to 2.5mW (0.5mA supply current). Wake-up occurs on the rising edge of CONV, requiring ≥350ns acquisition time (tACQ) before valid conversion - confirmed in TI's timing diagram Figure 4 and Table I.

Is ADS7818PG4 pin-compatible with other packages of the ADS7818 family?

ADS7818PG4 (MSOP-8) shares identical pinout and electrical behavior with ADS7818EB and ADS7818E, but is not pin-compatible with the plastic DIP-8 variants (ADS7818P/PB) due to differing physical layout and thermal pad configuration. Both MSOP-8 and DIP-8 versions use the same functional pin mapping (VREF, +In, –In, GND, CONV, DATA, CLK, +VCC), but mechanical mounting and PCB footprint differ.

What serial data format does ADS7818PG4 output, and can it be changed?

ADS7818PG4 outputs straight-binary data by default, MSB-first. However, it supports LSB-first transmission by asserting CONV HIGH during conversion and pulling it LOW during the 13th clock cycle - a hardware-configurable feature documented in Figure 5 of the datasheet. No firmware change or external logic is required to switch formats.