AS1538-BTST

Analog To Digital Converters (ADC) Overview

The AS1538-BTST is an 8-channel, 12-bit Analog-to-Digital Converter (ADC) from ams-OSRAM USA INC. It features a serial I²C interface and operates on a single supply voltage ranging from 2.7V to 5.25V. The device integrates a sample-and-hold amplifier, an internal asynchronous clock, and a 2.5V internal reference. Key electrical parameters include a maximum sampling rate of 50kSPS, no missing codes, and a high-speed I²C interface supporting up to 3.4MHz. Quiescent current varies by mode, with full shutdown current below 1.5µA. It is housed in a TSSOP-16 package.

Analog To Digital Converters (ADC) Feature Summary

• 8-Channel Multiplexer with Single-Ended or Differential Input Configuration
• 12-Bit Resolution with No Missing Codes and 50kSPS Sampling Rate
• High-Speed I²C Interface Operating at Up to 3.4MHz
• Integrated 2.5V Internal Reference with External Reference Option

Analog To Digital Converters (ADC) Applications

• Voltage-supply monitoring systems
• Isolated data acquisition circuits
• Transducer interfaces
• Battery-operated portable devices
• Remote data acquisition nodes

Analog To Digital Converters (ADC) Procurement Notes

Verify the ordering suffix BTST corresponds to the TSSOP-16 package variant as specified in the datasheet. Confirm that the component meets RoHS compliance requirements if applicable to the target assembly process. Ensure the supplier provides documentation confirming the revision level matches the source material.

Analog To Digital Converters (ADC) Selection Notes

Select the AS1538-BTST for applications requiring multi-channel analog signal digitization with minimal pin count. The choice between internal and external references depends on required dynamic range; use an external reference if input spans exceed the internal 2.5V limit. Consider the 3.4MHz I²C speed for high-throughput systems and verify power consumption constraints against the specified quiescent currents.

Analog To Digital Converters (ADC) Part Context

The AS1538 is part of the AS1538/AS1540 family of low-power data acquisition devices. While the AS1540 variant offers only 4 channels, the AS1538 provides 8 multiplexed inputs. Both share identical core ADC architecture, timing characteristics, and interface protocols, differing primarily in channel count and pin assignments for unused channels.

Analog To Digital Converters (ADC) Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Verify compatibility with existing I²C bus masters and address configurations when considering alternative components.

Analog To Digital Converters (ADC) FAQ

How is the slave address configured?

The first five bits are factory-set to 10010. The next two bits (A1 and A0) are set by the logic levels on pins A1 and A0 at startup, allowing up to four devices on the same bus.

What is the settling time for the internal reference?

With a 4.7µF reference capacitor, the settling time is approximately 1.4ms. This must be accounted for to achieve 12-bit accuracy when toggling the internal reference.

Can the device operate in differential mode?

Yes, by setting the SD bit in the command byte to 0, the device supports differential inputs using the COM pin as the negative terminal for selected channels.