ADA4960-1

Data Sheet

Rev. A | Page 16 of 19

ADC INTERFACING

The ADA4960-1 is a high speed amplifier with linearity

performance to drive high speed ADCs up to 1 GHz. Several

options are available to the designer to interface with an ADC.

The ADA4960-1 in Figure 38 is a differential input configuration,

using an input balun to provide the differential input signal. The

25 Ω resistors provide the input source match. The ADA4960-1

outputs can be directly connected to the ADC inputs as long as

the ADC input common mode is within the output common-

mode range of the ADA4960-1. The ADC V

connected to the ADA4960-1 VOCM input pin to align the

ADA4960-1 output voltages with the ADC inputs.

A 100 Ω resistor across the outputs of the ADA4960-1 enhances

system bandwidth and distortion performance when the ADA4960-1

is driving an ADC with high input impedance. Lighter load

resistance improves distortion performance and lowers the

overall bandwidth.

IIP

VIP

25Ω

25Ω

50Ω

100Ω

0.1µF

5V

ETC1-1-13

ADA4960-1

0.1µF

AC

IIN

VIN

VOP

ADC

VON

VOCM

Figure 38. Differential Input Configuration Directly Driving the ADC

The ADA4960-1 in Figure 39 is a single-ended input configura-

tion. The input is matched to the source with 50 Ω resistors. The

ADA4960-1 outputs can be directly connected to the ADC inputs

as long as the ADC input common mode is within the output

common-mode range of the ADA4960-1.

ADA4960-1

VOP

ADC

5V

VON

VOCM

IIP

VIP

50Ω

25Ω

50Ω

0.1µF

0.1µF

AC

IIN

VIN

100Ω

Figure 39. Single-Ended Input Configuration Directly Driving the ADC

The signal source can be directly connected to the ADA4960-1

inputs as long as the source dc level is within the common-mode

input range of the ADA4960-1, as shown in Figure 40.

ADA4960-1

VOP

ADC

5V

VON

VOCM

IIP

VIP

50Ω

25Ω

50Ω

AC

IIN

VIN

100Ω

Figure 40. Single-Ended Input Configuration, DC-Coupled Inputs and

Outputs

When the ADC input common mode is outside the output

common-mode range of the ADA4960-1, the outputs can be

ac-coupled to provide coupling, as shown in Figure 41.

ADA4960-1

VOP

ADC

5V

VON

IIP

VIP

50Ω

25Ω

50Ω

0.1µF

0.1µF

0.1µF

AC

IIN

VIN

0.1µF

100Ω

Figure 41. Single-Ended Input Configuration, AC-Coupled to the ADC

LINE DRIVER APPLICATIONS

The user accessible gain adjust and bandwidth extension

features allow configuration of the ADA4960-1 for line driver

and channel equalization applications from dc to 6.5 Gbps.

Because of its extremely low distortion performance and high

linearity, the ADA4960-1 can be deployed in cable and backplane

channels to extend channel length and improve signaling

margin for serial links using receive equalization and transmit

pre-emphasis. The ADA4960-1 unidirectional signal path is

protocol and encoding agnostic, supporting myriad signaling

types such as NRZ and PAM2/4/8/N, coded (8b/10b), uncoded,

and out-of-band (SATA-OOB) data.