herunterladen
SLOS214C − OCTOBER 1998 − REVISED MARCH 2007
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
D Separate Low Noise Preamp and PGA
Stages
D Shutdown Control
D Preamp Features
− Low Voltage Noise . . . 1.7 nV/√Hz
− Accessible Output Pin for External
Filtering
− Voltage Feedback, G
min
= −1, 2
− 100 MHz Bandwidth (−3 dB)
D PGA Features
− Digitally Programmable Gain
− −22 dB to 20 dB Gain/Attenuation Range
− 6 dB Step Resolution
− Output Clamp Protection
− 70 MHz Bandwidth (−3 dB)
− 175 V/µs Slew Rate
D Wide Supply Range ±4.5 V to ±16 V
D PowerPAD Package for Enhanced
Thermal Performance
description
The THS7001 (single) and THS7002 (dual) are high-speed programmable-gain amplifiers, ideal for applications
where load impedance can often vary. Each channel on this device consists of a separate low-noise input
preamp and a programmable gain amplifier (PGA). The preamp is a voltage-feedback amplifier offering a low
1.7-nV/√Hz
voltage noise with a 100-MHz (−3 dB) bandwidth. The output pin of the preamp is accessible so that
filters can be easily added to the amplifier.
The 3-bit digitally-controlled PGA provides a −22-dB to 20-dB attenuation/gain range with a 6-dB step
resolution. In addition, the PGA provides both high and low output clamp protection to prevent the output signal
from swinging outside the common-mode input range of an analog-to-digital converter. The PGA provides a
wide 70-MHz (−3 dB) bandwidth, which remains relatively constant over the entire gain/attenuation range.
Independent shutdown control is also provided for power conservation and multiplexing. These devices operate
over a wide ±4.5-V to ±16-V supply voltage range.
_
+
PREAMP V
CC+
PREAMP IN+
PREAMP IN−
PREAMP V
CC−
Preamp
PREAMP
OUT
PGA IN− G
2
G
1
G
0
PGA REFSHDN PGA
V
CC+
GNDPGA
V
CC−
CLAMP+ (V
H
)
CLAMP− (V
L
)
PGA OUT
_
+
Figure 1. THS7001 Block Diagram
Copyright 1999, Texas Instruments Incorporated
!"# $ %&'# "$ (&)*%"# +"#',
+&%#$ %! # $('%%"#$ (' #-' #'!$ '."$ $#&!'#$
$#"+"+ /""#0, +&%# (%'$$1 +'$ # '%'$$"*0 %*&+'
#'$#1 "** (""!'#'$,
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.
CAUTION: The THS7001 and THS7002 provides ESD protection circuitry. However, permanent damage can still occur if this
device is subjected to high-energy electrostatic discharges. Proper ESD precautions are recommended to avoid any performance
degradation or loss of functionality.
PowerPAD is a trademark of Texas Instruments Incorporated.
Verzeichnis
