OPA188-Q1 Datasheet, PDF (20/37 Pages) Texas Instruments – Precision, Low-Noise, Rail-to-Rail Output, 36-V, Zero-Drift, Automotive-Grade Operational Amplifier

OPA188-Q1, OPA2188-Q1
SBOS860 – APRIL 2017
www.ti.com
Feature Description (continued)
8.3.5 EMI Rejection
The OPAx188-Q1 series uses integrated electromagnetic interference (EMI) filtering to reduce the effects of EMI
interference from sources such as wireless communications and densely-populated boards with a mix of analog
signal chain and digital components. EMI immunity can be improved with circuit design techniques; the
OPAx188-Q1 series benefits from these design improvements. Texas Instruments™ has developed the ability to
accurately measure and quantify the immunity of an operational amplifier over a broad frequency spectrum
extending from 10 MHz to 6 GHz. Figure 39 shows the results of this testing on the OPAx188-Q1. Table 3 lists
the EMIRR IN+ values for the OPAx188-Q1 devices at particular frequencies commonly encountered in real-
world applications. Applications listed in Table 3 may be centered on or operated near the particular frequency
shown. Detailed information can also be found in EMI Rejection Ratio of Operational Amplifiers, available for
download from www.ti.com.
160
140
120
100
80
60
40
20
0
10M
100M
1G
10G
Frequency (Hz)
Figure 39. EMIRR Testing
FREQUENCY
400 MHz
900 MHz
1.8 GHz
2.4 GHz
3.6 GHz
5 GHz
Table 3. OPAx188-Q1 EMIRR IN+ for Frequencies of Interest
APPLICATION OR ALLOCATION
Mobile radio, mobile satellite, space operation, weather, radar, ultra-high frequency
(UHF) applications
Global system for mobile communications (GSM) applications, radio
communication, navigation, GPS (to 1.6 GHz), GSM, aeronautical mobile, UHF
applications
GSM applications, mobile personal communications, broadband, satellite, L-band
(1 GHz to 2 GHz)
802.11b, 802.11g, 802.11n, Bluetooth^®, mobile personal communications,
industrial, scientific and medical (ISM) radio band, amateur radio and satellite, S-
band (2 GHz to 4 GHz)
Radiolocation, aero communication and navigation, satellite, mobile, S-band
802.11a, 802.11n, aero communication and navigation, mobile communication,
space and satellite operation, C-band (4 GHz to 8 GHz)
EMIRR IN+
62.2 dB
74.7 dB
100.7 dB
102.4 dB
104.8 dB
100.3 dB
8.3.6 Capacitive Load and Stability
The device dynamic characteristics are optimized for a range of common operating conditions. The combination
of low closed-loop gain and high capacitive loads decreases the amplifier phase margin and can lead to gain
peaking or oscillations. As a result, larger capacitive loads must be isolated from the output. The simplest way to
achieve this isolation is to add a small resistor (for example, R_OUT equal to 50 Ω) in series with the output.
Figure 40 and Figure 41 show graphs of small-signal overshoot versus capacitive load for several values of
R_OUT. For details of analysis techniques and application circuits, see Feedback Plots Define Op Amp AC
Performance, available for download from www.ti.com.
20
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: OPA188-Q1 OPA2188-Q1