Information

Texas Instruments Signal Chain Guide 2013 | 17
Amplifiers and Comparators
High-Speed Amplifiers (>50 MHz)
Get more information: www.ti.com/product/THS4531
Get more information: www.ti.com/product/LMH6554
Ultra-Low-Power, Fully-Differential Operational Amplifier
THS4531
2.8 GHz Ultra-Linear Fully Differential Amplifier
LMH6554
The THS4531 is a low-power, fully-differential op amp with input common-mode range
below the negative rail and rail-to-rail output. The device is designed for low-power
data acquisition systems and high density applications where power consumption and
dissipation is critical.
The device features accurate output common-mode control that allows for dc coupling
when driving analog-to-digital converters (ADCs). This control, coupled with the input
common-mode range below the negative rail and rail-to-rail output, allows for easy
interface from single-ended ground-referenced signal sources to successive-approxi
-
mation registers (SARs), and delta-sigma (Δ∑) ADCs using only single-supply 2.5-V to
5-V power. The THS4531 is also a valuable tool for general-purpose, low-power differ-
ential signal conditioning applications.
The LMH6554 is a high performance fully dif
ferential amplifier designed to provide the
exceptional signal fidelity and wide large-signal bandwidth necessary for driving 8- to
16-bit high-speed data acquisition systems. This device has unity gain, small-signal
bandwidth of 2.8 GHz and allows operation at gains greater than unity without sacrific
-
ing response flatness, bandwidth, harmonic distortion, or output noise performance.
Key Features
• Ultra-lowpower
• Fully-differentialarchitecture
• Bandwidth:36MHz
• Slewrate:200V/µs
• THD:–120dBcat1kHz
(1 V
RMS
,RL=2kΩ)
• Inputvoltagenoise:
10 nV/
√
—
Hz (f = 1 kHz)
•
HighDCaccuracy:
• V
OS
drift:±4µV/°C(–40°Cto+125°C)
• A
OL
: 114 dB
• Rail-to-railoutput
• Negativerailinput
• Outputcommon-modecontrol
Applications
• Medicalequipment
• Military:sonarandradar
• Motorcontrol
• Personalnavigationdevice
• Smartmeters
Key Features
• Smallsignalbandwidth:2.8GHz
• 2V
PP
large signal bandwidth: 1.8 GHz
0.1 dB gain flatness: 830 MHz
• OIP3at150MHz:46.5dBm
• HD2/HD3at75MHz:–96/–97dBc
• Inputnoisevoltage:0.9nV/
√
—
Hz
• Inputnoisecurrent:11pA/
√
—
Hz
• Slewrate:6200V/μs
• Power:260mW
• Typicalsupplycurrent:52mA
• Package:14-leadLLP
Applications
• Cablemodemterminationsystem
• Militaryradar/sonar
• Softwaredefinedradio
• Wirelesscommunications
−140
−130
−120
−110
−100
−90
−80
−70
−60
−50
−40
−30
−20
−10
0
0 5 k 10 k 15 k 20 k 24 k
Frequency (Hz)
Magnitude (dBV)
V
S
= 5 V
G = 1 V/V
V
OUT
= 1 V
RMS
R
F
= 2 k Ω
R
L
= 600 Ω
LMH6554
Bias
Circuitry
Q2
Q1
I Tail
R
R
20k
Supply
Mid-Point
10k
V
–
V
+
V
EN
R1
ESD Proteciont
R2
LMH6554 functional block diagram