Texas Instruments THS0842IPFB

Overview

THS0842IPFB from Texas Instruments is a dual-channel, 8-bit, 40 MSPS analog-to-digital converter with simultaneous sample-and-hold inputs, single- or dual-parallel bus output, and 3.3 V TTL/CMOS-compatible digital I/O. It delivers 6.8-bit effective number of bits (ENOB) at 15 MHz input, supports differential or single-ended analog inputs, and operates on a single 3.3 V supply. It is used in baseband sampling for cable modems and set-top boxes.

For engineers reviewing the THS0842IPFB datasheet, THS0842IPFB pinout, THS0842IPFB application, or THS0842IPFB equivalent, this page provides verified specifications including 40 MSPS sampling rate, 600 MHz analog input bandwidth, dual I/Q channel architecture, internal/external reference flexibility, and TQFP-48 package compatibility - all critical for high-speed communication receiver design.

Technical Context

The THS0842IPFB implements a single-pipeline ADC architecture with six 2-bit stages plus a final flash stage, using digital correction logic to generate an 8-bit result without missing codes across –40°C to 85°C. Its dual-input path supports independent I+ / I– and Q+ / Q– differential analog channels, each sampled simultaneously with 3 ns aperture delay and 1.5 ps RMS jitter.

Timing is synchronized to an 80 MHz clock (enabling 40 MSPS conversion), with pipeline latency of 5.5 CLK cycles for I-channel and 6.5 CLK cycles for Q-channel data. Output timing is referenced to COUT/COUT latch clocks-not CLK-ensuring reliable data capture on falling edges due to output delay exceeding half a clock period at maximum rate.

Key Specifications

Pinout & Package

THS0842IPFB is housed in a 48-pin Thin Quad Flat Pack (TQFP) with 0.5 mm pitch, thermally enhanced for high-speed ADC operation. Pin functions are validated per TI SLAS246A datasheet Rev. August 2000.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel, 8-bit, 40 MSPS ADC applications.

Compared with ADS830U and MAX1186ECM+, the THS0842IPFB uniquely integrates dual simultaneous S/H, 3.3 V CMOS parallel buses, and internal reference flexibility - making it the only drop-in solution for space-constrained, single-supply I/Q digitizers requiring minimal external components.

Availability

THS0842IPFB is available at Aetrix Electronics and suitable for cable modem downstream receivers, set-top box digital tuners, and wireless local loop base stations requiring stable component supply across extended product lifecycles.

Supply support for THS0842IPFB 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 high-performance signal chain solutions for industrial, communications, and consumer markets.

The THS0842IPFB belongs to TI's high-speed data converter product line, designed specifically for cost-sensitive, power-efficient I/Q digitization in broadband communication infrastructure and test equipment.

FAQ

What is the maximum sampling rate supported by the THS0842IPFB?

The THS0842IPFB supports a maximum sampling rate of 40 MSPS, achieved with an 80 MHz master clock input. This rate applies to both I and Q channels simultaneously, as confirmed in the SLAS246A datasheet Section 8 (Timing Requirements). The device uses a single-pipeline architecture where each clock cycle initiates one conversion, and the 40 MSPS rate reflects the effective throughput after accounting for pipeline latency and dual-channel interleaving.

Does the THS0842IPFB require external voltage references?

No, the THS0842IPFB does not require external voltage references. It includes internal top (REFT) and bottom (REFB) reference circuits that generate stable reference voltages from AVDD. These internal references can be used directly, or disabled via PWDN_REF to allow external reference sources - offering design flexibility without mandatory external components. The datasheet specifies internal reference performance across temperature and supply variations.

How does the dual-bus output mode work on the THS0842IPFB?

In dual-bus output mode (SELB = low), the THS0842IPFB drives I-channel data on DA0–DA7 and Q-channel data on DB0–DB7 concurrently. This eliminates time-division multiplexing, allowing simultaneous capture of both I and Q words on separate 8-bit buses. The COUT and COUT signals serve as complementary latch clocks for their respective buses, ensuring deterministic timing alignment between I and Q data streams - critical for coherent demodulation.

What is the analog input configuration supported by the THS0842IPFB?

The THS0842IPFB supports both differential (I+/I–, Q+/Q–) and single-ended analog inputs. Its input structure includes internal common-mode level (CML) generation at (AVDD – AVSS)/2, enabling simplified ac-coupled differential designs. The datasheet confirms differential operation delivers optimal SFDR (>47 dBc) and crosstalk (< –52 dBc), while single-ended use is possible with appropriate biasing and reduced dynamic performance.

Is the THS0842IPFB pin-compatible with other members of the THS08xx family?

No, the THS0842IPFB is not pin-compatible with other THS08xx variants such as THS0830 or THS0820. While sharing functional similarities, the THS0842IPFB has a unique 48-pin TQFP pinout optimized for dual I/Q inputs, dual parallel buses, and dedicated reference/control terminals. Pin assignments for DA/DB buses, COUT/COUT, PWDN_REF, and SELB differ from earlier family members - requiring distinct PCB layout and signal routing.