Texas Instruments ADC081S101CISD

Overview

ADC081S101 from Texas Instruments is a single-channel, 8-bit successive-approximation ADC with SPI/QSPI/MICROWIRE/DSP-compatible serial interface, operating at 0.5–1 Msps sample rates on a single 2.7V–5.25V supply, delivering 49.7 dB SNR and ±0.05 LSB INL for portable instrumentation and remote data acquisition systems.

For engineers reviewing the ADC081S101 datasheet, ADC081S101 pinout, ADC081S101 application, or ADC081S101 equivalent, key selection considerations include its guaranteed performance across 500 ksps–1 Msps (not just at one rate), low 2.0 mW power at 3V, WSON/SOT-23 package compatibility, and straight-binary output timing aligned to SCLK falling edges.

Technical Context

The ADC081S101 implements a charge-redistribution DAC core with internal track-and-hold, acquiring input voltage on the falling edge of CS and completing conversion within 16 SCLK cycles. Its analog input range is 0V to VA, and it uses straight-binary coding with no missing codes.

It supports variable power management via CS-controlled shutdown mode, reducing consumption to 2.5 µW at 5V, and features tri-state SDATA output with configurable quiet time (tQUIET ≥ 50 ns) between conversions to prevent bus contention in multi-device systems.

Key Specifications

Pinout & Package

The ADC081S101 is available in 6-lead WSON (NGF) and SOT-23 (DBV) packages; both share identical pinout and are functionally interchangeable. The exposed center pad (CISD suffix) must be connected to GND for thermal and electrical stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit SAR ADC applications.

Compared with ADC081S051 and ADC081S021, the ADC081S101 uniquely guarantees full 8-bit linearity and 49.7 dB SNR at 1 Msps - making it the only option in the family for high-speed portable instrumentation requiring both speed and precision without interpolation or oversampling.

Availability

ADC081S101 is available at Aetrix Electronics and suitable for portable medical sensors, remote environmental monitoring, and industrial PLC analog input modules requiring stable component supply across extended product lifecycles.

Supply support for ADC081S101 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 is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in precision data converters and low-power design.

The ADC081Sxx family was engineered for space-constrained, battery-operated measurement systems needing guaranteed performance across variable sample rates - targeting portable instrumentation, sensor nodes, and industrial diagnostics.

FAQ

What is the maximum guaranteed sample rate for ADC081S101 with full specifications met?

The ADC081S101 is fully specified and guaranteed to meet all electrical characteristics-including INL ±0.3 LSB, SNR ≥49 dB, and DNL ±0.3 LSB-at sample rates up to 1 Msps. This is confirmed in the Electrical Characteristics table and Operating Ratings section of the SNAS310D datasheet, with test conditions explicitly covering fSAMPLE = 500 ksps to 1 Msps.

Does ADC081S101 require an external reference voltage?

No, the ADC081S101 uses its VA supply pin as the reference voltage-its analog input range is 0V to VA, and all conversion results scale accordingly. No external reference is needed, simplifying BOM and layout; however, VA must be clean and well-bypassed to preserve SNR performance.

Can ADC081S101 interface directly with a 1.8V microcontroller?

Yes - while VA must be 2.7V–5.25V, the digital inputs (CS and SCLK) tolerate −0.3V to +5.25V regardless of VA, per the Absolute Maximum Ratings. A 1.8V MCU can drive CS and SCLK directly; SDATA output swings from 0V to VA, so level translation may be required for 1.8V logic capture unless the MCU input accepts 5.25V-tolerant signals.

What is the purpose of the three leading zeros and four trailing zeros in ADC081S101's serial output format?

The ADC081S101 outputs 15 bits per frame: 3 leading zeros + 8 data bits (MSB first) + 4 trailing zeros. This fixed 15-bit structure ensures consistent framing and simplifies synchronization in DSP or FPGA receivers. The leading zeros allow time for bus stabilization before valid data arrives; trailing zeros provide margin for clock jitter and enable clean tri-state reversion after the 16th SCLK falling edge.

How does ADC081S101 handle power-down, and what is the recovery time?

The ADC081S101 enters shutdown mode when CS is held high before the 10th SCLK falling edge after initiation. Power drops to 2.5 µW (at 5V). Recovery is immediate: bringing CS low starts conversion on the next falling edge, with full performance achieved after the first complete 16-SCLK cycle - no additional power-up delay is required, as confirmed by tPOWER-UP = 1 µs in the timing specifications.