ANALOG DEVICES AD9286 Service Manual

8-Bit, 500 MSPS, 1.8 V

FEATURES

Single 1.8 V supply operation SNR: 49.3 dBFS at 200 MHz input at 500 MSPS SFDR: 65 dBc at 200 MHz input at 500 MSPS Low power: 315 mW at 500 MSPS On-chip interleaved clocking On-chip reference and track-and-hold

1.2 V p-p analog input range for each channel Differential input with 500 MHz bandwidth LVDS-compliant digital output On-chip voltage reference and sample-and-hold circuit DNL: ±0.2 LSB Serial port control options

Interleaved clock timing adjustment Offset binary, Gray code, or twos complement data format Optional clock duty cycle stabilizer

Built-in selectable digital test pattern generation Pin-programmable power-down function Available in 48-lead LFCSP

APPLICATIONS

Battery-powered instruments Handheld scope meters Low cost digital oscilloscopes OTS: video over fiber

Analog-to-Digital Converter (ADC)

AD9286

GENERAL DESCRIPTION

The AD9286 is an 8-bit, monolithic sampling, analog-to-digital converter (ADC) that supports interleaved operation and is optimized for low cost, low power, and ease of use. Each ADC operates at up to a 250 MSPS conversion rate with outstanding dynamic performance.

The AD9286 takes a single sample clock and, with an on-chip clock divider, time interleaves the two ADC cores (each running at one-half the clock frequency) to achieve the rated 500 MSPS. By using the SPI, the user can accurately adjust the timing of the sampling edge per ADC to minimize the image spur energy.

The ADC requires a single 1.8 V supply and an encode clock for full performance operation. No external reference components are required for many applications. The digital outputs are LVDS compatible.

The AD9286 is available in a Pb-free, 48-lead LFCSP that is specified over the industrial temperature range of −40°C to +85°C.

PRODUCT HIGHLIGHTS

1. Integrated 8-Bit, 500 MSPS ADC.

2. Single 1.8 V Supply Operation with LVDS Outputs.

3. Power-Down Option Controlled via a Pin-Programmable

Setting.

FUNCTIONAL BLOCK DIAGRAM

CLK+ CLK–

VIN1+ VIN1–

VCM

VREF

1.0V

REF

VIN2– VIN2+

UXCLK– UXCLK+

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.

REF

SELECT

RBIAS AUXCLKEN AGND AVDD DRVDD DRGND

ADC

×1.5

ADC

SDIO/

PWDN

CLOCK

MANAGEMENT

Figure 1.

CSB

SPI

SCLK

OUTPUT

INTERLEAVE

DCO

GENERATION

AD9286

D7+ (MSB), D7– (MSB)

LVDS

D0+ (LSB), D0– (LSB)

OUTPUT BUFFER

DCO+ DCO–

09338-001