1FEATURES

2• High Speed:

– Data Rate: 1.25MSPS

– Bandwidth: 615kHz

• Outstanding Performance:

– SNR: 92dB at f IN = 100kHz, –1dBFS

– THD: –103dB at fIN = 100kHz, –6dBFS

– SFDR: 105dB at fIN = 100kHz, –6dBFS

• Ease-of-Use:

– High-Speed 3-Wire Serial Interface

– Directly Connects to TMS320 DSPs

– On-Chip Digital Filter Simplifies Anti-Alias

Requirements

– Simple Pin-Driven Control—No On-Chip

Registers to Program

– Selectable On-Chip Voltage Reference

– Simultaneous Sampling with Multiple

ADS1601s

• Low Power:

– 330mW at 1.25MSPS

– 145mW at 625kSPS

– Power-Down Mode

APPLICATIONS

• Sonar

• Vibration Analysis

• Data Acquisition

DESCRIPTION

The ADS1601 is a high-speed, high-precision,

delta-sigma analog-to-digital converter (ADC)

manufactured on an advanced CMOS process. The

ADS1601 oversampling topology reduces clock jitter

sensitivity during the sampling of high-frequency,

large amplitude signals by a factor of four over that

achieved by Nyquist-rate ADCs. Consequently,

signal-to-noise ratio (SNR) is particularly improved.

Total harmonic distortion (THD) is –103dB, and the

spurious-free dynamic range (SFDR) is 105dB

Optimized for power and performance, the ADS1601

dissipates only 330mW while providing a full-scale differential input range of ±0.94VREF. Having such a

wide input range makes out-of-range signals

uncommon. The OTR pin indicates if an analog input

out-of-range condition does occur. The differential

input signal is measured against the differential

reference, which can be generated internally on the

ADS1601 or supplied externally.

The ADS1601 uses an inherently stable advanced

modulator with an on-chip decimation filter. The filter

stop band extends to 19.3MHz, which greatly

simplifies the anti-aliasing circuitry. The modulator

samples the input signal up to 20MSPS, depending

on fCLK, while the 16x decimation filter uses a series

of four half-band FIR filter stages to provide 75dB of

stop band attenuation and 0.001dB of passband

ripple.

Output data is provided over a simple 3-wire serial

interface at rates up to 1.25MSPS, with a –3dB

bandwidth of 615kHz. The output data or its

complementary format directly connects to DSPs

such as TI’s TMS320 family, FPGAs, or ASICs. A

dedicated synchronization pin enables simultaneous

sampling with multiple ADS1601s in multi-channel

systems. Power dissipation is set by an external

resistor that allows a reduction in dissipation when

operating at slower speeds. All of the ADS1601

features are controlled by dedicated I/O pins, which

simplify operation by eliminating the need for on-chip

registers.

The high performing, easy-to-use ADS1601 is

especially suitable for demanding measurement

applications in sonar, vibration analysis, and data

acquisition. The ADS1601 is offered in a small, 7mm

× 7mm TQFP-48 package and is specified

from –40°C to +85°C.