MAX186CCAP

ADCs/DACs - Special Purpose Overview

The MAX186CCAP is a low-power, 8-channel, serial 12-bit analog-to-digital converter (ADC) manufactured by Analog Devices Inc./Maxim Integrated. It integrates an 8-channel multiplexer, high-bandwidth track/hold circuitry, and a successive-approximation ADC core within a 20-pin SSOP package. The device operates on a single +5V or dual ±5V supply, achieving a sampling rate of 133ksps with a conversion time of 10µs using the internal clock. Key electrical specifications include a small-signal bandwidth of 4.5MHz, a total harmonic distortion of -80dB, and a spurious-free dynamic range of 80dB. It features software-configurable unipolar/bipolar and single-ended/differential input modes.

ADCs/DACs - Special Purpose Feature Summary

• Integrates an 8-channel multiplexer, track/hold, and 12-bit SAR ADC in a compact 20-SSOP package.
• Features a 4-wire serial interface compatible with SPI, QSPI, MICROWIRE, and TMS320 DSPs.
• Includes an internal 4.096V reference voltage source and a reference-buffer amplifier for gain trimming.
• Supports ultra-low power consumption with two software-selectable power-down modes reducing current to under 10µA.

ADCs/DACs - Special Purpose Applications

• Portable data logging systems
• High-accuracy process control instrumentation
• Automatic testing equipment
• Battery-powered medical instruments

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific grade suffix 'C' corresponds to the required operating temperature range of 0°C to +70°C. Confirm that the 20-SSOP package dimensions match the PCB footprint requirements. Ensure the design accommodates the internal compensation mode if the SHDN pin is pulled high, or external compensation if left unconnected.

ADCs/DACs - Special Purpose Selection Notes

Select the MAX186CCAP when an integrated internal reference is preferred over the MAX188, which requires an external reference. This component is suitable for applications requiring a 133ksps sampling rate with minimal external logic due to its serial interface compatibility. Consider the 1.5mA operating current and 2µA power-down current for battery life calculations in portable designs.

ADCs/DACs - Special Purpose Part Context

The MAX186CCAP belongs to the MAX186/MAX188 family of low-power, 8-channel, serial 12-bit ADCs. The 'C' suffix denotes the commercial temperature grade (0°C to +70°C), while the 'A', 'B', and 'D' grades offer different accuracy specifications. The 'CAP' designation specifically identifies the shrink small-outline package variant.

ADCs/DACs - Special Purpose Replacement Considerations

The MAX188CCAP is a functional substitute within the same package but requires an external reference voltage at the VREF pin instead of utilizing the internal reference found in the MAX186 series.

ADCs/DACs - Special Purpose FAQ

How does the MAX186 handle differential inputs?

In differential mode, the MAX186 samples the difference between paired channels (CH0/CH1, CH2/CH3, CH4/CH5, or CH6/CH7). This configuration is pseudo-differential, meaning only the signal at the positive input (IN+) is sampled while the negative input (IN-) must remain stable relative to AGND during conversion.

What is the function of the SHDN pin regarding the reference buffer?

Pulling the SHDN pin high puts the reference-buffer amplifier into internal compensation mode. Leaving the SHDN pin unconnected places the amplifier in external compensation mode, which requires an external capacitor at the VREF pin.

Can the MAX186 operate without an external clock?

Yes, the MAX186 can use its internal clock for conversions. In this mode, the SSTRB output indicates when the conversion starts and ends, allowing the microprocessor to read the data at its own convenience using any serial clock rate up to 10MHz.