AD8253 datasheet(26/34 Pages) AD

26 / 34 page

LTC6373

Rev. 0

For more information www.analog.com

CCM

6373 F08

CDIFF

180pF

CCM

LTC6373

IN+

IN-

REF

GND

1.8V

VREF

VDD

VREF

ADC

VOCM

VREF

+15V

-15V

VREF/2G

-VREF/2G

V-IN

V+IN

VREF/2

used to

set G

VREF/2G

-VREF/2G

SAR ADC: use any ADC listed in Table 3

- ADC: use AD7134

Figure 8. LTC6373 Driving Precision ADC

As a more specific example, Figure 9 and Figure 10 show

typical Signal-to-Noise Ratio (SNR) and Total Harmonic

Distortion (THD) of the LTC6373 driving the AD4020 SAR

ADC (with high-Z mode enabled) at a near full-scale signal

for various ADC throughputs. The recommended RC filter

values used in Figure 8 for optimum performance at each

throughput are listed in Table 4, as well as the selected

reference voltage (VREF).

Table 4. RC Filter Selection for LTC6373 Driving AD4020 (at Various Throughputs)

ADC

Throughput

(Msps)

VREF

(V)

Signal Level at LTC6373

Outputs = ADC Inputs (VP-P)

R (Ω) CCM

(pF)

CDIFF

(pF)

Typical SNR

(dB)

Typical THD

(dB)

AD4020

1.8

442

180

Open See Figure 9 See Figure 10

887

180

Open See Figure 9 See Figure 10

0.6

887

180

Open See Figure 9 See Figure 10

fIN = 1kHz

THROUGHPUT = 1.8Msps

THROUGHPUT = 1Msps

THROUGHPUT = 0.6Msps

LTC6373 GAIN SETTING (G)

0.25 0.5

100

SNR for LTC6373 Driving AD4020

6373 F09

fIN = 1kHz

THROUGHPUT = 1.8Msps

THROUGHPUT = 1Msps

THROUGHPUT = 0.6Msps

LTC6373 GAIN SETTING (G)

0.25 0.5

–130

–125

–120

–115

–110

–105

–100

–95

–90

THD for LTC6373 Driving AD4020

6373 F10

Figure 9. SNR for LTC6373 Driving AD4020

Figure 10. THD for LTC6373 Driving AD4020

APPLICATIONS INFORMATION

AD8253 Datasheet(PDF) 26 Page - Analog Devices

AD8253 Datasheet(HTML) 26 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

Datasheet Download

Link URL