ADS7818PB Equivalent & Substitute Parts

Part Overview

The ADS7818PB is a 12-bit Analog to Digital Converter (ADC) manufactured by Texas Instruments, designed for single-channel data acquisition applications. It features a Successive Approximation Register (SAR) architecture with an internal reference, 500 kSPS sampling rate, and differential input configuration. The device is packaged in an 8-PDIP through-hole format and operates across the industrial temperature range of -40°C to 85°C.

The ADS7818PB is classified as obsolete. Identifying equivalent and substitute parts is necessary to support legacy system maintenance, design updates, and procurement continuity when original inventory becomes unavailable.

Substiute Parts

ADS7818PB

Texas InstrumentsIn Stock: 1448ADS7818PB Datasheet

Current PartRFQ

MCP3201-BI/P

Microchip TechnologyIn Stock: 2703MCP3201-BI/P Datasheet

MFR RecommendedRFQ

MCP3201-CI/P

Microchip TechnologyIn Stock: 6202MCP3201-CI/P Datasheet

MFR RecommendedRFQ

ADS7818P

Texas InstrumentsIn Stock: 2070ADS7818P Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the ADS7818PB is evaluated based on core functional parameters: resolution, sampling rate, input configuration, data interface, and package compatibility. The substitute parts are grouped into two categories:

MFR Recommended Substitutes (MCP3201-BI/P, MCP3201-CI/P): These Microchip Technology devices maintain 12-bit resolution, SPI interface, SAR architecture, and 8-PDIP packaging. However, they operate at 100 kSPS (lower sampling rate) and feature pseudo-differential inputs with external reference requirements. Supply voltage range is expanded to 2.7V–5.5V, providing greater flexibility for mixed-voltage systems.

Parametric Equivalent (ADS7818P): This Texas Instruments part is a direct parametric match to the ADS7818PB, sharing identical specifications including 500 kSPS sampling rate, differential input type, internal reference, and fixed 5V supply requirements. The primary difference is packaging designation and product status classification.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Parametric Equivalence): The ADS7818P provides identical electrical and thermal performance to the ADS7818PB. Both devices maintain 500 kSPS sampling rate, differential input configuration, and internal reference architecture. Selection between these two Texas Instruments parts depends on packaging availability and inventory status. Both are classified as obsolete and carry ROHS3 compliance.

For Active Product Substitution: The MCP3201-BI/P and MCP3201-CI/P are active products from Microchip Technology, offering improved long-term availability and supply chain stability. These devices are suitable for applications where the following conditions are met: (1) sampling rate requirements do not exceed 100 kSPS, (2) pseudo-differential input configuration is acceptable for the signal source, (3) external reference voltage can be provided, and (4) supply voltage flexibility (2.7V–5.5V range) is beneficial or required. Both MCP3201 variants maintain ROHS3 compliance and identical package geometry.

Frequently Asked Questions (FAQ)

Q: Can the MCP3201 series directly replace the ADS7818PB without circuit modifications?

A: Partial compatibility exists. The 8-DIP package footprint is identical, and SPI interface pinouts are compatible. However, the MCP3201 requires an external reference voltage circuit, whereas the ADS7818PB has an internal reference. Additionally, the MCP3201 input stage is pseudo-differential rather than fully differential. Circuit redesign is necessary to accommodate these differences.

Q: What is the impact of the 100 kSPS sampling rate on MCP3201 substitutes compared to the 500 kSPS ADS7818PB?

A: The MCP3201 sampling rate is 5 times lower. Applications requiring high-speed signal acquisition or bandwidth above 50 kHz (Nyquist limit at 100 kSPS) cannot use the MCP3201 without performance degradation. Applications with sampling requirements below 100 kSPS are unaffected.

Q: Are the ADS7818PB and ADS7818P interchangeable?

A: Yes, from an electrical and thermal specification standpoint. Both devices are parametrically identical 12-bit SAR ADCs with 500 kSPS sampling rate, differential inputs, and internal references. Both are obsolete products. Substitution depends solely on package availability and inventory status.

Q: What are the compliance and regulatory implications of these substitutes?

A: All listed parts (ADS7818PB, ADS7818P, MCP3201-BI/P, MCP3201-CI/P) are ROHS3 compliant, REACH unaffected, and classified under ECCN EAR99. No regulatory barriers exist for substitution within this product group.

Q: Can the ADS7818PB operate at supply voltages other than 5V?

A: No. The ADS7818PB requires fixed 5V supply for both analog and digital domains. The MCP3201 series supports 2.7V–5.5V operation, providing voltage flexibility if system redesign is feasible.