Analog Devices Inc. AD9240AS

Overview

AD9240AS from Analog Devices is a monolithic 14-bit, 10 MSPS analog-to-digital converter (ADC) with integrated sample-and-hold amplifier and programmable voltage reference. It operates on a single +5 V supply, delivers 77.5 dB SNR+D at 500 kHz input, exhibits ±2.5 LSB INL and 0.36 LSB input-referred noise (VREF = 2.5 V), and is used in direct-IF downconversion receivers up to 45 MHz.

For engineers reviewing the AD9240AS datasheet, AD9240AS pinout, AD9240AS application, or AD9240AS equivalent, this page provides verified DC/AC specifications, MQFP-44 terminal mapping, differential/single-ended input configuration guidance, and validated alternative ADCs for data acquisition, communications, and imaging systems requiring 14-bit resolution at 10 MSPS.

Technical Context

The AD9240AS employs a four-stage differential pipelined architecture with digital error correction logic to guarantee no missing codes across –40°C to +85°C. Each stage uses MDACs with gains of 16 (first stage) and 8 (subsequent stages), plus 1-bit redundancy for flash error correction.

Its analog front-end supports flexible input configurations: differential (VINA–VINB) or single-ended, with selectable 2 V or 5 V p-p spans via internal reference (1 V or 2.5 V) and SENSE pin control. Clock-driven sampling occurs on the rising edge, with 3-cycle pipeline latency and aperture jitter of 4 ps rms.

Key Specifications

Pinout & Package

AD9240AS is housed in a 44-lead Metric Quad Flatpack (MQFP) with 0.8 mm lead pitch and exposed thermal pad. Package thermal resistance is θ_JA = 53.2°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 14-bit, 10 MSPS ADC applications.

Compared with AD9240BSTZ, the AD9240AS offers identical conversion performance in a more compact MQFP package with superior thermal resistance (θ_JA = 53.2°C/W vs. ~65°C/W for LQFP), while ADS8325IPFB trades speed and integration for higher static accuracy - making it unsuitable as a drop-in replacement but viable for low-speed precision alternatives.

Availability

AD9240AS is available at Aetrix Electronics and suitable for communications infrastructure, medical imaging, industrial PLCs, and test equipment requiring stable component supply with long-term lifecycle support.

Supply support for AD9240AS 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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD9240AS belongs to Analog Devices' high-speed precision ADC product line, designed specifically for demanding data acquisition, communications, and instrumentation applications requiring 14-bit resolution at multi-MSPS rates with integrated analog front-end functionality.

FAQ

What is the maximum sampling rate supported by the AD9240AS?

The AD9240AS supports a maximum sampling rate of 10 MSPS under standard operating conditions (AVDD = DVDD = DRVDD = +5 V, f_CLK = 10 MHz). Its clock period must be ≥100 ns, and performance remains stable up to 1 ms period at +25°C. The actual achievable rate can be reduced via the BIAS pin resistor to lower power consumption, but 10 MSPS is the rated maximum specified in the datasheet for the AD9240AS.

Does the AD9240AS require an external voltage reference?

No, the AD9240AS does not require an external voltage reference. It integrates a programmable internal reference delivering either 1 V or 2.5 V, selected via the SENSE pin. However, an external reference may be connected to the VREF pin if tighter dc accuracy or lower temperature drift is required - the AD9240AS fully supports this configuration while maintaining all specified performance metrics.

What is the meaning of the OTR signal on the AD9240AS?

The OTR (Out-of-Range) signal on the AD9240AS is an active-high digital output indicating that the analog input exceeded the valid full-scale range (±VREF). When asserted, OTR works in conjunction with the MSB (BIT 1) to distinguish between high overflow (MSB = 1, OTR = 1) and low overflow (MSB = 0, OTR = 1), enabling robust saturation detection in real-time signal processing chains using the AD9240AS.

Can the AD9240AS operate with a 3.3 V digital interface?

Yes, the AD9240AS supports 3.3 V digital interfacing through its dedicated DRVDD supply pin. When DRVDD = +3.3 V, the digital outputs meet CMOS logic thresholds: VOH ≥ +2.4 V (IOH = 50 µA) and VOL ≤ +0.7 V (IOL = 50 µA). This allows direct connection to 3.3 V FPGAs or processors without level-shifting, while AVDD and DVDD remain at +5 V to maintain analog and core digital performance - a key flexibility feature of the AD9240AS.

How does the BIAS pin affect power consumption and performance of the AD9240AS?

The BIAS pin on the AD9240AS controls power consumption and maximum sampling rate via an external resistor (RBIAS). A 2 kΩ resistor yields the rated 10 MSPS operation at 285 mW typ; increasing RBIAS reduces both clock rate capability and power draw - e.g., 10 kΩ lowers power to ~200 mW and max rate to ~6 MSPS. All AC/DC specifications in the AD9240AS datasheet are measured at RBIAS = 2 kΩ, so deviation affects timing and dynamic performance predictably.