Texas Instruments ADS900E

Overview

ADS900E from Texas Instruments is a 10-bit, 20MHz pipelined analog-to-digital converter (ADC) with internal reference, single-ended input range of +1.0V to +2.0V, wideband track-and-hold (350MHz small-signal bandwidth), and SSOP-28 package. It delivers 49dB SNR at 500kHz input and supports portable instrumentation, cable modems, and set-top boxes.

For engineers reviewing the ADS900E datasheet, ADS900E pinout, ADS900E application, or ADS900E equivalent, this page provides verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternative parts with functional differences, and supply support for industrial embedded and communications hardware development.

Technical Context

The ADS900E implements a 9-stage pipelined architecture with 2-bit quantizers per stage and digital error correction to guarantee no missing codes and ±0.7LSB differential linearity at 500kHz. Its internal resistor ladder establishes +1.25V (REFB) and +1.75V (REFT) references, yielding a +1.5V common-mode voltage (CM) at Pin 26.

It uses a non-overlapping two-phase internal clock for track-and-hold operation, supports straight offset binary output coding, and features dedicated LVDD (Pin 2) for independent digital output driver supply control. Aperture jitter is specified at 7ps rms, directly limiting SNR in high-frequency sampling applications.

Key Specifications

Pinout & Package

ADS900E is housed in a 28-pin SSOP (DB) package with 0.635mm pitch, moisture sensitivity level MSL-2 (260°C peak reflow), and RoHS-compliant NiPdAu lead finish. Thermal resistance θ_JA is 89°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed ADC applications.

Compared with ADS900E, ADS830U trades resolution and integration for speed and smaller package, while MAX1186EEE+ offers higher speed and same resolution but requires different supply and packaging - neither is pin-compatible, making ADS900E preferred for legacy SSOP-28 designs needing 10-bit/20MSPS with internal reference.

Availability

ADS900E is available at Aetrix Electronics and suitable for portable instrumentation, IF/baseband communications, and cable modem applications requiring stable component supply across extended temperature ranges (–40°C to +85°C).

Supply support for ADS900E 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 high-performance data converters.

The ADS900E belongs to TI's precision high-speed ADC product line, designed specifically for demanding communications, test equipment, and video digitization applications where resolution, linearity, and low-power operation are critical.

FAQ

What is the maximum sampling rate supported by the ADS900E?

The ADS900E is fully specified for operation at 20 million samples per second (20MSPS). This rate is validated across the full operating temperature range (–40°C to +85°C) and supply voltage range (+2.7V to +3.7V). At 20MSPS, the device maintains its published dynamic performance including 49dB SNR at 500kHz and 53dBFS SFDR, making it suitable for IF sampling in communications receivers and real-time test instrumentation where timing determinism is essential. The ADS900E does not support guaranteed operation above 20MSPS.

Does the ADS900E require external reference components?

No, the ADS900E does not require external reference components. It integrates a precision internal reference ladder that provides fixed +1.25V (REFB) and +1.75V (REFT) reference voltages, generating a stable +1.5V common-mode voltage (CM) at Pin 26. Pins 21 (LpBy) and 25 (LnBy) are provided for optional 0.1µF bypass capacitors to enhance reference stability, but no external resistors, op-amps, or voltage references are needed for basic operation. The +1.0V output at Pin 23 is unbuffered and intended to remain unconnected.

How does the power-down mode function on the ADS900E?

The ADS900E enters power-down mode when Pin 17 (Pwrdn) is driven high, reducing supply current by approximately 70% to ~10mW. During power-down, digital outputs enter high-impedance state and conversion accuracy is suspended. After Pwrdn is returned low, the first five clock cycles produce invalid data due to internal pipeline reset latency. An internal 50kΩ pull-down resistor ensures the device remains active by default if Pwrdn is left unconnected. Power-down recovery time is 18ns from Pwrdn high-to-low transition to valid output enable.

What is the purpose of the LVDD pin on the ADS900E?

The LVDD pin (Pin 2) supplies power exclusively to the digital output drivers of the ADS900E, allowing independent control of logic voltage levels. This enables direct interfacing with 3V FPGA or ASIC I/O banks without level shifters. When LVDD = +3V, output high voltage (VOH) is ≥+2.4V and output low voltage (VOL) is ≤+0.4V - meeting TTL/HCT and low-voltage CMOS thresholds. Driving LVDD to other voltages scales VOH/VOL proportionally, but TI specifies performance only at +3V. LVDD must be decoupled locally with a 0.1µF capacitor.

Can the ADS900E operate with a single-ended input configuration?

Yes, the ADS900E is explicitly designed for single-ended operation. In this mode, the complementary input (Pin 24) is tied to the common-mode voltage (Pin 26, +1.5V), converting the single-ended signal (applied to Pin 27) into a fully differential signal internally. This configuration provides 2× gain, improving SNR performance. The specified single-ended input range is +1.0V to +2.0V, centered at +1.5V. TI provides application circuits (e.g., Figure 3 and Figure 6 in SBAS058A) using op-amps like OPA680 to condition ground-referenced signals for this mode.