OPA2835 Datasheet, PDF (37/53 Pages) National Semiconductor (TI) – Ultra Low-Power, Rail-to-Rail Out, Negative Rail In, VFB Op Amp

www.ti.com
OPA835
OPA2835
SLOS713E – JANUARY 2011 – REVISED JULY 2013
OPA835 and ADS8326 Combined Performance
To show achievable performance, the OPA835 is tested as the drive amplifier for the ADS8326. The ADS8326 is
a 16-bit, micro power, SAR ADC with pseudo-differential inputs and sample rates up to 250kSPS. It offers
excellent noise and distortion performance in a small 8-pin SOIC or VSSOP (MSOP) package. Low power and
small size make the ADS8326 and OPA835 an ideal solution for portable and battery-operated systems, for
remote data-acquisition modules, simultaneous multichannel systems, and isolated data acquisition.
The circuit shown in Figure 79 is used to test the performance, Figure 80 is the FFT plot with 10kHz input
frequency showing the spectral performance, and the tabulated AC analysis results are in Table 3.
VSIG
0V
VIN
2.7 V
4.02 k
2k
4.02 k
2.7V
VS ₊
OPA835
VS-
VSIG
1.35 V
100
2.2 nF
5 V 2.5 V
+In ^{VDD REF}
ADS 8326
-In
2k
2k
Tone (Hz)
10k
Figure 79. OPA835 and ADS8326 Test Circuit
0
-20
-40
-60
-80
-100
-120
-140
0
20
40
60
80
100
120
f - Frequency - Hz
Figure 80. ADS8326 and OPA835 10kHz FFT
Signal (dBFS)
–0.85
Table 3. AC Analysis
SNR (dBc)
81.9
THD (dBc)
–87.5
SINAD (dBc)
80.8
SFDR (dBc)
89.9
Copyright © 2011–2013, Texas Instruments Incorporated
Product Folder Links: OPA835 OPA2835
Submit Documentation Feedback
37