OPA211AIDRGR Datasheet, PDF (19/37 Pages) Texas Instruments – 1.1nV/√Hz Noise, Low Power, Precision Operational Amplifier in Small DFN-8 Package

OPA211
OPA2211
www.ti.com...................................................................................................................................................... SBOS377G – OCTOBER 2006 – REVISED MAY 2009
most likely will not operate normally. If the supplies
are low impedance, then the current through the
steering diodes can become quite high. The current
level depends on the ability of the input source to
deliver current, and any resistance in the input path.
THERMAL CONSIDERATIONS
A primary issue with all semiconductor devices is
junction temperature (T_J). The most obvious
consideration is assuring that T_J never exceeds the
absolute maximum rating specified for the device.
However, addressing device thermal dissipation has
benefits beyond protecting the device from damage.
Even modest increases in junction temperature can
decrease op amp performance, and
temperature-related errors can accumulate.
Understanding the power generated by the device
within the specific application and assessing the
thermal effects on the error tolerance lead to a better
understanding of system performance and
thermal-dissipation needs. For dual-channel products,
the worst-case power resulting from both channels
must be determined. Products with a thermal pad
(DFN and PowerPAD devices) provide the best
thermal conduction away from the junction; see the
Thermal Resistance from Junction to Pad parameter
(θ_JP) in the Electrical Characteristics section. The use
of packages with a thermal pad improves thermal
dissipation. The device achieves its optimal
performance through careful board and system
design that considers characteristics such as board
thickness, metal layers, component spacing, airflow,
and board orientation. Refer to these application
notes (available for download at www.ti.com) for
additional details: SZZA017A, SCBA017, and
SPRA953A. For unusual loads and signals, see
SBOA022.
DFN packages are physically small, and have a
smaller routing area, improved thermal performance,
and improved electrical parasitics. Additionally, the
absence of external leads eliminates bent-lead
issues.
The DFN package can be easily mounted using
standard printed circuit board (PCB) assembly
techniques. See Application Note QFN/SON PCB
Attachment (SLUA271) and Application Report Quad
Flatpack No-Lead Logic Packages (SCBA017), both
available for download at www.ti.com.
The exposed leadframe die pad on the bottom of
the package must be connected to V–. Soldering
the thermal pad improves heat dissipation and
enables specified device performance.
DFN LAYOUT GUIDELINES
The exposed leadframe die pad on the DFN package
should be soldered to a thermal pad on the PCB. A
mechanical drawing showing an example layout is
attached at the end of this data sheet. Refinements to
this layout may be necessary based on assembly
process requirements. Mechanical drawings located
at the end of this data sheet list the physical
dimensions for the package and pad. The five holes
in the landing pattern are optional, and are intended
for use with thermal vias that connect the leadframe
die pad to the heatsink area on the PCB.
Soldering the exposed pad significantly improves
board-level reliability during temperature cycling, key
push, package shear, and similar board-level tests.
Even with applications that have low-power
dissipation, the exposed pad must be soldered to the
PCB to provide structural integrity and long-term
reliability.
DFN PACKAGE
The OPA211 is offered in an DFN-8 package (also
known as SON). The DFN package is a QFN
package with lead contacts on only two sides of the
bottom of the package. This leadless package
maximizes board space and enhances thermal and
electrical characteristics through an exposed pad.
Copyright © 2006–2009, Texas Instruments Incorporated
Submit Documentation Feedback
19
Product Folder Link(s): OPA211 OPA2211