OPA132
,
OPA2132
,
OPA4132
SBOS054B –JANUARY 1995–REVISED SEPTEMBER 2015
www.ti.com
9 Power Supply Recommendations
The OPAx132 is specified for operation from 5 V to 36 V (±2.5 V to ±18 V); many specifications apply from
–40°C to 85°C. Parameters that can exhibit significant variance with regard to operating voltage or temperature
are presented in the Typical Characteristics.
CAUTION
Supply voltages larger than 36 V can permanently damage the device; see the
Absolute Maximum Ratings.
Place 10-nF bypass capacitors close to the power-supply pins to reduce errors coupling in from noisy or high-
impedance power supplies. For more detailed information on bypass capacitor placement, see the Layout
Guidelines.
10 Layout
10.1 Layout Guidelines
For best operational performance of the device, use good PCB layout practices, including:
• Noise can propagate into analog circuitry through the power pins of the circuit as a whole and operational
amplifier itself. Bypass capacitors are used to reduce the coupled noise by providing low-impedance power
sources local to the analog circuitry.
– Connect low-ESR, 10 nF ceramic bypass capacitors between each supply pin and ground, placed as
close to the device as possible. A single bypass capacitor from V+ to ground is applicable for single-
supply applications.
• Separate grounding for analog and digital portions of circuitry is one of the simplest and most-effective
methods of noise suppression. One or more layers on multilayer PCBs are usually devoted to ground planes.
A ground plane helps distribute heat and reduces EMI noise pickup. Make sure to physically separate digital
and analog grounds paying attention to the flow of the ground current. For more detailed information refer to
Circuit Board Layout Techniques, SLOA089.
• In order to reduce parasitic coupling, run the input traces as far away from the supply or output traces as
possible. If these traces cannot be kept separate, crossing the sensitive trace perpendicular is much better as
opposed to in parallel with the noisy trace.
• Place the external components as close to the device as possible. As shown in Layout Example, keeping RF
and RG close to the inverting input minimizes parasitic capacitance.
• Keep the length of input traces as short as possible. Always remember that the input traces are the most
sensitive part of the circuit.
• Consider a driven, low-impedance guard ring around the critical traces. A guard ring can significantly reduce
leakage currents from nearby traces that are at different potentials.
• Cleaning the PCB following board assembly is recommended for best performance.
• Any precision integrated circuit may experience performance shifts due to moisture ingress into the plastic
package. Following any aqueous PCB cleaning process, baking the PCB assembly is recommended to
remove moisture introduced into the device packaging during the cleaning process. A low temperature, post
cleaning bake at 85°C for 30 minutes is sufficient for most circumstances.
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Product Folder Links: OPA132 OPA2132 OPA4132
