TDA8798 Datasheet, PDF (17/24 Pages) NXP Semiconductors – Dual 8-bit, 100 Msps A/D converter with DPGA

Philips Semiconductors
Dual 8-bit, 100 Msps A/D converter with
DPGA
Objective specification
TDA8798
TEST AND APPLICATION INFORMATION
handbook, full pagewidth
100 nF
(2)
100 nF
(2)
3.3 V
3.3 V
100 nF⁽¹⁾
VSSA
100 nF⁽¹⁾
VSSD
VSSA
VSSD
100 nF
VSSD
VSSD
3.3 V
100 nF⁽¹⁾
VSSO
VSSO
DPGA2N
1
DPGA2
2
VSSA ^{68 pF(3) DPGAC2} ₃
VSSA
3.3 V
VIN2N
VIN2
Vref2
100 nF⁽¹⁾ _VDDA2 ⁴
5
100 nF⁽⁴⁾ _VIN2N
6
100 nF⁽⁴⁾
VIN2
7
VSSA2
8
VIN1
VIN1N
100 nF⁽⁴⁾
100 nF⁽⁴⁾
VSSA1
9
VIN1
10
VIN1N
11
3.3 V
VDDA1
12
100 nF^{(1) Vref1}
VSSA
13
DPGAC1
VSSA
14
68 pF⁽³⁾ _DPGA1
15
DPGA1N
16
TDA8798HL
B7
48
B7
B6
47
B6
B5
46
B5
B4
45
B4
B3
44
B3
B2
43
B2
B1
42
B1
B0
41
B0
A0
40
A0
A1
39
A1
A2
38
A2
A3
37
A3
A4
36
A4
A5
35
A5
A6
34
A6
A7
33
A7
100 nF
(2)
100 nF
(2)
VSSA
VSSD
100 nF⁽¹⁾
100 nF
VSSD
VSSA
100 nF⁽¹⁾
VSSD
VSSO
100 nF⁽¹⁾
VSSO
3.3 V
3.3 V
3.3 V
MGM867
Analog and digital supplies must be separate and decoupled.
(1) Supply decoupling capacitor must be placed as close as possible to the chip’s pin. Value may need changing depending on the external filter
characteristics.
(2) Capacitor may be replaced when an external filter is used with AC coupling.
(3) Capacitor value may be changed to adjust settling time between DPGA gain changes.
(4) Capacitor value may need changing depending on the high-pass cut-off frequency of the external filter.
Fig.7 Application diagram.
1999 Sep 16
17