THS4509 Datasheet, PDF (1/30 Pages) Texas Instruments – WIDEBAND, LOW NOISE, LOW DISTORTION FULLY DIFFERENTIAL AMPLIFIER

THS4509
www.ti.com
SLOS454 – JANUARY 2005
WIDEBAND, LOW NOISE, LOW DISTORTION FULLY DIFFERENTIAL AMPLIFIER
FEATURES
• Fully Differential Architecture
• Centered Input Common-mode Range
• Minimum Gain of 2V/V (6 dB)
• Bandwidth: 1900 MHz (100 mVpp, G = 10 dB,
R_L = 200 Ω)
• Slew Rate: 6600 V/µs (2V step, G = 10 dB)
• 1% Settling Time: 2 ns (2 V step, G = 10 dB)
• HD₂: –75 dBc at 100 MHz (2 Vpp, G = 10 dB,
R_L = 1 kΩ)
• HD₃: –80 dBc at 100 MHz (2 Vpp, G = 10 dB,
R_L = 1 kΩ)
• OIP₂: 79 dBm at 70 MHz (2 Vpp envelope,
G = 10 dB)
• OIP₃: 43 dBm at 70 MHz (2 Vpp envelope,
G = 10 dB)
• Input Voltage Noise: 1.9 nV/√Hz (f >10 MHz)
• Noise Figure: 17.1 dB (50 Ω System, G = 10
dB)
• Output Common-Mode Control
• Power Supply:
– Voltage: 3 V (±1.5 V) to 5 V (±2.5 V)
– Current: 37.7 mA
• Power-Down Capability: 0.65 mA
APPLICATIONS
• 5 V Data Acquisition Systems High
Linearity ADC Amplifier
• Wireless Communication
• Medical Imaging
• Test and Measurement
DESCRIPTION
The THS4509 is a wideband, fully differential op amp
designed for 5 V data acquisition systems. It has very
low noise at 1.9 nV/√Hz, and extremely low harmonic
distortion of –75 dBc HD₂ and –80 dBc HD₃ at 100
MHz with 2 Vpp, G = 10 dB, and 1 kΩ load. Slew rate
is very high at 6600 Vµs and with settling time of 2 ns
to 1% (2 V step) it is ideal for pulsed applications. It is
designed for minimum gain of 6 dB, but is optimized
for gain of 10 dB.
To allow for dc coupling to ADCs, its unique output
common-mode control circuit maintains the output
common-mode voltage within 3 mV offset (typ) from
the set voltage, when set within 0.5 V of mid-supply,
with less than 4 mV differential offset voltage. The
common-mode set point is set to mid-supply by
internal circuitry, which may be over-driven from an
external source.
The input and output are optimized for best perform-
ance with their common-mode voltages set to
mid-supply. Along with high performance at low
power supply voltage, this makes for extremely high
performance single supply 5 V data acquisition sys-
tems. The combined performance of the THS4509 in
a gain of 10 dB driving the ADS5500 ADC, sampling
at 125 MSPS, is 81 dBc SFDR and 69.1 dBc SNR
with a –1 dBFS signal at 70 MHz.
The THS4509 is offered in a Quad 16-pin leadless
QFN package (RGT), and is characterized for oper-
ation over the full industrial temperature range from
–40°C to 85°C.
V_IN
From
50 Ω
Source
100 Ω
69.8 Ω
348 Ω
2.5 V
0.22 µF
49.9 Ω
100 Ω
THS 4509
69.8 Ω
CM
−2.5 V
348 Ω
487 Ω
1:1
487 Ω ^{56.3 Ω}
V_OUT
To 50 Ω
Test
Equipment
Open
-75
G = 10 dB,
-80 VO = 2 VPP,
R_L = 1 kW
-85
-90
-95
HD₃
-100
-105
-1 10
1
HD₂
10
100
f - Frequency - MHz
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.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005, Texas Instruments Incorporated