AD7478A Analog Devices, AD7478A Datasheet - Page 12

• Manufacturer Part Number: AD7478A
• Description: 8-Bit, 1 MSPS, Low-Power A/D Converter in SC70 and MSOP Packages
• Manufacturer: Analog Devices

Specifications of AD7478A

• Resolution (bits): 8bit
• # Chan: 1
• Sample Rate: 1.2MSPS
• Interface: Ser,SPI
• Analog Input Type: SE-Uni
• Ain Range: Uni Vdd
• Adc Architecture: SAR
• Pkg Type: SC70,SOP

AD7476A/AD7477A/AD7478A
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 7, Figure 8, and Figure 9 each show a typical FFT plot for
the AD7476A, AD7477A, and AD7478A, respectively, at a
1 MSPS sample rate and 100 kHz input frequency. Figure 10
shows the signal-to-(noise + distortion) ratio performance vs.
the input frequency for various supply voltages while sampling
at 1 MSPS with an SCLK frequency of 20 MHz for the
AD7476A.
–115
–105
–15
–35
–55
–75
–95
–25
–45
–65
–85
–5
5
0
0
Figure 7. AD7476A Dynamic Performance at 1 MSPS
Figure 8. AD7477A Dynamic Performance at 1 MSPS
50
50
100
100
150
150
FREQUENCY (kHz)
FREQUENCY (kHz)
200
200
250
250
300
300
8192 POINT FFT
V
f
f
SINAD = 72.05dB
THD = –82.87dB
SFDR = –87.24dB
350
350
8192 POINT FFT
V
f
f
SINAD = 61.67dB
THD = –79.59dB
SFDR = –82.93dB
SAMPLE
IN
SAMPLE
IN
DD
DD
= 100kHz
= 100kHz
= 2.7V
= 2.35V
400
400
= 1MSPS
= 1MSPS
450
450
500
500
Rev. F | Page 12 of 28
Figure 11 and Figure 12 show INL and DNL performance for
the AD7476A. Figure 13 shows a graph of the total harmonic
distortion vs. the analog input frequency for different source
impedances when using a supply voltage of 3.6 V and sampling
at a rate of 1 MSPS (see the Analog Input section). Figure 14
shows a graph of the total harmonic distortion vs. the analog
input signal frequency for various supply voltages while
sampling at 1 MSPS with an SCLK frequency of 20 MHz.
–15
–25
–35
–45
–55
–65
–75
–85
–95
–66
–67
–68
–69
–70
–71
–72
–73
–74
–5
Figure 10. AD7476A SINAD vs. Input Frequency at 1 MSPS
5
10
0
Figure 9. AD7478A Dynamic Performance at 1 MSPS
50
100
150
FREQUENCY (kHz)
FREQUENCY (kHz)
200
V
DD
250
V
= 5.25V
100
DD
= 2.35V
V
300
DD
= 2.7V
350
V
8192 POINT FFT
SINAD = 49.77dB
THD = –75.51dB
SFDR = –70.71dB
V
f
f
SAMPLE
IN
DD
DD
= 100kHz
= 3.6V
= 2.35V
400
V
DD
= 1MSPS
= 4.75V
450
1000
500