Differential Inputs, 1 MSPS/500 kSPS, Dual

Simultaneous Sampling SAR ADCs

Data Sheet

AD4680/AD4681

Rev. 0

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FEATURES

16-bit ADC family

Dual simultaneous sampling

Fully differential analog inputs

Throughput conversion rate

1 MSPS for AD4680

500 kSPS for AD4681

SNR (typical)

100 dB with 8× OSR, RES = 1

On-chip oversampling function

Resolution boost function

INL (maximum) 1.5 LSBs

2.5 V internal reference at 10 ppm/°C

High speed serial interface

−40°C to +125°C operation

3 mm × 3 mm, 16-lead LFCSP

Wide common-mode range

Alert function

APPLICATIONS

Motor control position feedback

Motor control current sense

Sonar

Power quality

Data acquisition systems

Erbium doped fiber amplifier (EDFA) applications

Inphase (I) and quadrature (Q) demodulation

GENERAL DESCRIPTION

The AD4680/AD4681 are 16-bit, pin-compatible, dual simultane-

ous sampling, high speed, low power, successive approximation

register (SAR) analog-to-digital converters (ADCs) that operate

from a 3.0 V to 3.6 V power supply and feature throughput rates

of 1 MSPS for the AD4680 and 500 kSPS for the AD4681. The

analog input type is differential, accepts a wide common-mode

input voltage, and is sampled and converted on the falling edge

of CS. Integrated on-chip oversampling blocks improve dynamic

range and reduce noise at lower bandwidths. A buffered internal

2.5 V reference is included. Alternatively, an external reference

up to 3.3 V can be used.

The conversion process and data acquisition use standard control

inputs, allowing easy interfacing to microprocessors or digital

signal processors (DSPs). The device is compatible with 1.8 V,

2.5 V, and 3.3 V interfaces using a separate logic supply. The

AD4680/AD4681 are available in a 16-lead lead frame chip scale

package (LFCSP) with operation specified from −40°C to +125°C.

COMPANION PRODUCTS

ADC Drivers: ADA4896-2, ADA4940-2, ADA4807-2, LTC6227

Voltage References: ADR4533, ADR4525

Low Dropout Regulators: ADP166, ADP7104, ADP7182

Additional companion products on the AD4680 and AD4681

product pages

Table 1. Related Products

Input Type

16-Bit

14-Bit

12-Bit

Differential

AD7380

AD7381

Pseudo Differential

AD7383

AD7384

Single-Ended

AD7386

AD7387

AD7388

FUNCTIONAL BLOCK DIAGRAM

ADC A

SDOA

DIGITAL

CONTROLLER

SCLK

1µF

3.3V

1µF

3.3V

GND

SDI

CS

SDOB/ALERT

REFIO

REFCAP

GND

REGCAP

OVER-

SAMPLING

ADC B

OVER-

SAMPLING

OSC

REF

LDO

CONTROL

LOGIC

AD4680/AD4681

C1

R

R

0V

0V

C1

C2

C2

C1

C1

0V

(

(

0V

R

R

Figure 1.