Texas Instruments ADC78H89CIMT

Overview

ADC78H89CIMT from Texas Instruments is a 12-bit, 7-channel, 500 KSPS successive-approximation ADC with independent analog (AVDD: +2.7V to +5.25V) and digital (DVDD: +2.7V to AVDD) supplies, SPI/QSPI/MICROWIRE-compatible serial interface, and TSSOP-16 packaging. It delivers ±1 LSB INL/DNL, 72.8 dB SNR at 40.2 kHz, and operates across −40°C to +85°C for industrial sensor data acquisition.

For engineers reviewing the ADC78H89CIMT datasheet, ADC78H89CIMT pinout, ADC78H89CIMT application, or ADC78H89CIMT equivalent, key selection considerations include its 7-channel multiplexed analog input architecture, 16-cycle throughput timing, straight-binary output format, low-power shutdown mode (0.3 µW @ 3V), and dual-supply noise isolation capability.

Technical Context

The ADC78H89CIMT employs a charge-redistribution SAR architecture with integrated track-and-hold, acquiring input signals over three SCLK cycles before sampling on the fourth falling edge. Its internal control logic manages channel selection via an 8-bit serial Control Register loaded on DIN during each conversion frame.

It supports variable power management through CS-driven operation: full functionality when CS is low (1.5 mW @ 3V), automatic power-down between conversions, and deep shutdown (0.3 µW) when CS remains high. The device uses AVDD as its reference voltage and requires separate analog/digital bypassing per TI layout guidelines.

Key Specifications

Pinout & Package

ADC78H89CIMT is packaged in a 16-lead TSSOP (PW package), with exposed pad not electrically connected. Pin spacing is 0.65 mm, body dimensions 5.0 mm × 4.4 mm × 1.2 mm, suitable for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and ADS8320EB, ADC78H89CIMT uniquely balances 500 KSPS throughput, 7-channel flexibility, dual-supply noise immunity, and ultra-low shutdown power-making it optimal for battery-operated, multi-signal industrial and medical edge nodes requiring both speed and efficiency.

Availability

ADC78H89CIMT is available at Aetrix Electronics and suitable for automotive navigation systems, portable medical instruments, and industrial process controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADC78H89CIMT 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 and embedded processing technologies, with decades of expertise in precision data converters and industrial-grade IC design.

The ADC78H89CIMT belongs to TI's legacy high-performance SAR ADC product line, engineered specifically for cost-sensitive, low-power, multi-channel data acquisition in harsh industrial and portable environments.

FAQ

What is the maximum clock frequency supported by ADC78H89CIMT?

The ADC78H89CIMT supports a maximum SCLK frequency of 8 MHz, with guaranteed performance at that rate. Minimum clock frequency is 50 kHz. At 8 MHz, the device achieves its rated 500 KSPS throughput using 16 SCLK cycles per conversion. Operating outside this range may cause timing violations or reduced AC performance in ADC78H89CIMT.

Does ADC78H89CIMT require an external voltage reference?

No, ADC78H89CIMT uses AVDD as its internal reference voltage-no external reference is required. The LSB step size equals AVDD / 4096, so reference accuracy and noise directly impact absolute measurement accuracy. For highest precision, AVDD must be clean and stable; TI recommends local 0.1 µF ceramic + 1 µF tantalum bypassing within 1 cm of the AVDD pin on the ADC78H89CIMT.

How does ADC78H89CIMT handle channel selection during continuous conversion?

ADC78H89CIMT loads new channel selection via its 8-bit Control Register on each conversion frame. Writing ADD2–ADD0 bits on DIN during one conversion determines the input channel sampled in the *next* conversion-introducing a one-sample delay. In continuous mode (CS held low), this allows dynamic channel sequencing without gaps, provided the host updates DIN before the 8th rising SCLK edge of each frame in ADC78H89CIMT.

What is the aperture delay specification for ADC78H89CIMT?

The aperture delay for ADC78H89CIMT is specified as 4 ns maximum. This is the time between the fourth falling edge of SCLK (when the track-to-hold transition occurs) and the instant the analog input is acquired for conversion. This low, fixed delay enables precise time-of-flight or phase-sensitive measurements when synchronized to an external clock in ADC78H89CIMT-based systems.

Can ADC78H89CIMT operate with AVDD = 3.3V and DVDD = 1.8V?

No-DVDD must be ≥ +2.7V and ≤ AVDD per the ADC78H89CIMT datasheet. Setting DVDD = 1.8V violates the DVDD minimum rating and risks functional failure or increased digital output leakage. Valid configurations include AVDD = DVDD = 3.3V or AVDD = 5.0V / DVDD = 3.3V. Always ensure DVDD does not exceed AVDD by more than 300 mV to prevent ESD diode conduction in ADC78H89CIMT.