Microchip Technology MCP3208-BI/P

Overview

MCP3208-BI/P from Microchip Technology is a 12-bit successive-approximation analog-to-digital converter (ADC) with 8 single-ended or 4 pseudo-differential input channels, on-chip sample-and-hold, SPI serial interface (modes 0,0 and 1,1), ±1 LSB max INL (B-grade), and industrial temperature range (–40°C to +85°C). It enables high-accuracy sensor digitization in battery-powered data loggers.

For engineers reviewing the MCP3208-BI/P datasheet, MCP3208-BI/P pinout, MCP3208-BI/P application, or MCP3208-BI/P equivalent, key selection criteria include guaranteed ±1 LSB integral nonlinearity at 12-bit resolution, 100 ksps sampling rate at 5V, SPI timing compatibility with microcontroller hardware ports, and support for both single-ended and pseudo-differential analog input configurations.

Technical Context

The MCP3208-BI/P implements a SAR architecture with internal 20 pF sample-and-hold capacitor, requiring 1.5 clock cycles for analog acquisition starting on the fourth rising CLK edge after the start bit. Conversion completes in 12 clock cycles, delivering straight-binary 12-bit output MSB-first on DOUT at the falling edge of each clock.

Its SPI interface supports dual modes (0,0 and 1,1), accepts channel configuration via DIN (SGL/DIFF + D2:D0 bits), and uses CS/SHDN for both communication initiation and standby entry. Input voltage range is VSS to VREF in single-ended mode, and IN− ±100 mV with IN+ ranging from IN− to VREF + IN− in pseudo-differential mode.

Key Specifications

Pinout & Package

Package: 16-pin PDIP (Plastic Dual In-line Package), 0.300-inch body width, through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit SAR ADC applications.

Compared with MCP3208-I/P, the MCP3208-BI/P guarantees tighter ±1 LSB INL for metrology-grade accuracy; versus ADS7822U, it trades maximum speed for integrated sample-and-hold, lower power, and pseudo-differential capability-making it superior for portable, noise-sensitive, or calibration-critical designs.

Availability

MCP3208-BI/P is available at Aetrix Electronics and suitable for industrial sensor interface, portable data acquisition, process control loop, and medical instrumentation requiring stable component supply and long-term manufacturability.

Supply support for MCP3208-BI/P 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

Microchip Technology Inc. is a leading provider of microcontrollers, analog devices, and Flash-IP solutions, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.

The MCP3208-BI/P belongs to Microchip's precision SAR ADC product line, designed specifically for embedded systems needing low-power, multi-channel, SPI-compatible analog digitization with minimal external components.

FAQ

What is the maximum sampling rate of the MCP3208-BI/P at 3.3V supply?

The MCP3208-BI/P achieves a maximum sampling rate of 50 ksps when operated at VDD = 2.7V; at 3.3V, its performance aligns with the 2.7V specification since the limiting factor is minimum clock frequency constraints-not supply voltage headroom. The device maintains full 12-bit accuracy and ±1 LSB INL across this range, with clock frequency capped at 1.0 MHz per datasheet Section 1.0 Electrical Specifications.

Does the MCP3208-BI/P support true differential input mode?

No, the MCP3208-BI/P supports only pseudo-differential input mode-where one channel serves as IN+ and another as IN−, with IN− restricted to ±100 mV around VSS. It does not implement fully differential inputs (e.g., balanced ±VREF swing). This architecture enables common-mode noise rejection while retaining single-ended signal chain simplicity, as confirmed in Section 4.1 Analog Inputs of DS21298E.

Can the MCP3208-BI/P operate with an internal reference?

No, the MCP3208-BI/P requires an external reference voltage applied to the VREF pin; it has no internal voltage reference. The reference input determines full-scale range (VSS to VREF), and LSB size equals VREF ÷ 4096. External reference selection directly impacts absolute accuracy-microcontroller AVCC or precision ICs like REF3025 may be used depending on system requirements.

What is the purpose of the NC pins on the MCP3208-BI/P PDIP package?

The MCP3208-BI/P in 16-pin PDIP has two No-Connect (NC) pins: Pin 5 and Pin 6. These pins are physically present but internally unconnected and must remain unconnected in PCB layout. They serve mechanical spacing and package symmetry purposes only-no routing, grounding, or pulling is permitted, as stated in Table 3-1 Pin Function Table of DS21298E.

How does the CS/SHDN pin function during conversion and standby?

The CS/SHDN pin serves dual roles: pulled low to initiate SPI communication and conversion, and pulled high to terminate conversion and place the MCP3208-BI/P into 500 nA standby mode. It must be held high between conversions to minimize power; asserting CS low mid-conversion aborts the current cycle and resets internal logic. This behavior is defined in Section 3.7 and Figure 5-1 of DS21298E.