AD7877 Analog Devices, AD7877 Datasheet - Page 11

• Manufacturer Part Number: AD7877
• Description: Touch Screen Controller
• Manufacturer: Analog Devices

Specifications of AD7877

• Resolution (bits): 12bit
• # Chan: 9
• Sample Rate: 125kSPS
• Interface: Ser
• Analog Input Type: SE-Uni
• Ain Range: Uni (Vref),Uni 2.5V
• Adc Architecture: SAR
• Pkg Type: CSP

Data Sheet
3145
3135
3125
3115
3105
3095
3085
3075
3065
3055
3045
1183
1182
1181
1180
1179
1178
1177
1176
982
981
980
979
978
977
976
975
–50
2.7
2.7
Figure 18. ADC Code vs. Temperature (2.7 V Supply)
2.8
2.8
–30
2.9
2.9
Figure 19. Temp1 vs. V
Figure 20. Temp0 vs. V
–10
3.0
3.0
TEMPERATURE (°C)
10
3.1
3.1
V
V
CC
CC
(V)
(V)
3.2
3.2
30
CC
CC
3.3
3.3
50
3.4
3.4
70
3.5
3.5
3.6
3.6
90
Rev. D | Page 11 of 44
Figure 22. Typical FFT Plot for the Auxiliary Channels of the AD7877
–110
–130
–150
2.5
3.50
3.25
3.00
2.75
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
–10
–30
–50
–70
–90
10
6
0
–20
0
0
0
at 90 kHz Sample Rate and 10 kHz Input Frequency
Figure 23. DAC Source and Sink Current Capability
DAC O/P SINK ABILITY
NO CAP
0.711µs SETTLING TIME
1
Figure 21. Internal V
0
2
10k
20
SOURCE/SINK CURRENT (mA)
SNR 70.25dB
THD 78.11dB
3
TURN-ON TIME (µs)
4
40
FREQUENCY
20k
REF
5
vs. Turn-On Time
100nF CAP
54.64µs SETTLING TIME
DAC O/P SOURCE ABILITY
60
6
30k
80
7
8
100
AD7877
40k
9
120
10