THS4503-EP_17 Datasheet, PDF (20/40 Pages) Texas Instruments – WIDEBAND, LOW-DISTORTION FULLY DIFFERENTIAL AMPLIFIERS

THS4503−EP
SGLS291A − APRIL 2005 − JANUARY 2012
www.ti.com
APPLICATION INFORMATION
MAXIMUM DIE TEMPERATURE TO PREVENT
OSCILLATION
The THS4503 may have low level oscillation when the die
temperature (also called junction temperature) exceeds
+60°C and is not recommended for new designs where the
die temperature is expected to exceed +60°C.
The oscillation is due to internal design and external
configuration is not expected to mitigate or reduce the
problem. This problem is random due to normal process
variations and normal testing cannot identify problem
units.
The THS4500 and THS4501 are recommended
replacement devices.
The die temperature depends on the power dissipation
and the thermal resistance of the device and can be
approximated with the following formula:
Die Temperature = P_DISS × θ_JA + T_A
Where:
P_DISS ≈ (V_S(TOTAL) × I_Q) + (V_S+ − V_OUT) × I_OUT) × θ_JA + T_A
Table 1 shows the estimated maximum ambient
temperature (T_A max) in °C for package option of the
THS4503 using the thermal dissipation rating given in the
PACKAGE DISSIPATION RATINGS table for a JEDEC
standard High−K test PCB. For each case shown,
V_S(TOTAL) = 10V, R_L = 800 Ω differential, and the quiescent
current = 32mA (the maximum over 0°C to 70°C
temperature range). The last entry for each package
option lists the worst case where the output voltage is 5V
DC.
Table 1. Estimated Maximum Ambient
Temperature Per Package Option
Package/Device
PWR Pad MSOP
THS4503DGN
Worst Case
Vout
0V
2 Vpp
4 Vpp
6 Vpp
8 Vpp
5 DC
q_JA
T_A max
58.4°C/W
41.3°C
40.8°C
40.4°C
40.1°C
39.8°C
39.5°C
FULLY DIFFERENTIAL AMPLIFIERS
Differential signaling offers a number of performance
advantages in high-speed analog signal processing
systems, including immunity to external common-mode
noise, suppression of even-order nonlinearities, and
increased dynamic range. Fully differential amplifiers not
only serve as the primary means of providing gain to a
differential signal chain, but also provide a monolithic
solution for converting single-ended signals into
differential signals for easier, higher performance
processing. The THS4500 family of amplifiers contains
products in Texas Instruments’ expanding line of
high-performance fully differential amplifiers. Information
on fully differential amplifier fundamentals, as well as
implementation specific information, is presented in the
applications section of this data sheet to provide a better
understanding of the operation of the THS4500 family of
devices and to simplify the design process for designs
using these amplifiers.
Applications Section
D Fully Differential Amplifier Terminal Functions
D Input Common-Mode Voltage Range and the
THS4500 Family
D Choosing the Proper Value for the Feedback and
Gain Resistors
D Application Circuits Using Fully Differential
Amplifiers
D Key Design Considerations for Interfacing to an
Analog-to-Digital Converter
D Setting the Output Common-Mode Voltage With the
V_OCM Input
D Saving Power With Power-Down Functionality
D Linearity: Definitions, Terminology, Circuit
Techniques, and Design Tradeoffs
D An Abbreviated Analysis of Noise in Fully
Differential Amplifiers
D Printed-Circuit Board Layout Techniques for Optimal
Performance
D Power Dissipation and Thermal Considerations
D Power Supply Decoupling Techniques and
Recommendations
D Evaluation Fixtures, Spice Models, and Applications
Support
D Additional Reference Material
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