Datasheet
1
FEATURES
APPLICATIONS
DESCRIPTION
THS4508
V
IN
R =75
S
W
V
Signal
V
S-
V
CM
R
O
R
O
V
OUT-
V
OUT+
V =5V
S+
175 W
175 W
75 W
130 W
130 W
348 W
348 W
THS4508
www.ti.com
.................................................................................................................................... SLAS459E – SEPTEMBER 2005 – REVISED SEPTEMBER 2008
WIDEBAND, LOW NOISE, LOW DISTORTION FULLY DIFFERENTIAL AMPLIFIER
To allow for dc coupling to analog-to-digital
converters (ADCs), its unique output common-mode
• Fully Differential Architecture
control circuit maintains the output common-mode
• Common-Mode Input Range Includes the
voltage within 5-mV offset (typical) from the set
Negative Rail
voltage, when set within 0.5 V of mid-supply. The
common-mode set point is set to mid-supply by
• Minimum Gain of 2 V/V (6 dB)
internal circuitry, which may be over-driven from an
• Bandwidth: 2 GHz
external source.
• Slew Rate: 6400 V/ µ s
The THS4508 is a high-performance amplifier that
• 1% Settling Time: 2 ns
has been optimized for use in high performance, 5-V
• HD
2
: – 72 dBc at 100 MHz
single-supply data acquisition systems. The output
has been optimized for best performance with its
• HD
3
: – 79 dBc at 100 MHz
common-mode voltages set to mid-supply, and the
• OIP
2
: 78 dBm at 70 MHz
input has been optimized for best performance with
• OIP
3
: 42 dBm at 70 MHz
its common-mode voltage set to 0.7 V. High
performance at a low power-supply voltage is ideal
• Input Voltage Noise: 2.3 nV/ √ Hz (f > 10 MHz)
for high-performance, single-supply 5-V
• Noise Figure: 19.2 dB (G = 10 dB)
data-acquisition systems with a minimum parts count.
• Output Common-Mode Control
The combined performance of the THS4508 in a gain
• 5-V Power Supply Current: 39.2 mA
of 10-dB driving the ADS5500 ADC, sampling at 125
MSPS, is 82-dBc SFDR, and 68.3-dBc SNR with a
• Power-Down Capability: 0.65 mA
– 1-dBFS signal at 70 MHz.
The THS4508 is offered in a quad 16-pin leadless
QFN package (RGT), and is characterized for
• 5-V Data-Acquisition Systems
operation over the full industrial temperature range
• High Linearity ADC Amplifier
from – 40 ° C to +85 ° C.
• Wireless Communication
• Medical Imaging
• Test and Measurement
The THS4508 is a wideband, fully-differential
operational amplifier designed for single-supply 5-V
data acquisition systems. It has very low noise at 2.3
nV/ √ Hz, and extremely low harmonic distortion of – 72
dBc HD
2
and – 79 dBc HD
3
at 100 MHz with 2 V
PP
,
G = 10 dB, and 1-k Ω load. Slew rate is very high at
6400 V µ s, and with settling time of 2 ns to 1% (2 V
Figure 1. Video Buffer
step), it is ideal for pulsed applications. It is designed
for minimum gain of 6 dB, but is optimized for gain of
10 dB.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Copyright © 2005 – 2008, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.