LM358 Pinout: Two Op Amps and Their Real Signal Limits
The LM358 pinout contains two operational amplifiers sharing one supply pair. Reading the pin names is only the start: input common-mode range, output swing and the exact device suffix determine what a circuit can do. An ordinary LM358 is not a rail-to-rail precision amplifier simply because it works from a single supply.
Read the standard eight-pin arrangement
For the common eight-pin package in the linked TI datasheet, amplifier one uses output 1, inverting input 2 and noninverting input 3. Pin 4 is the low supply. Amplifier two uses noninverting input 5, inverting input 6 and output 7, with positive supply on pin 8. Confirm package orientation and any alternative package before wiring.
Separate classic and newer suffix specifications
LM358, LM358A, LM358B and other variants have different limits and performance tables. The B version’s supply, offset or speed specification should not be silently assigned to an unidentified classic LM358. Match the complete manufacturer part code and temperature range, particularly when replacing a device in an existing circuit.
Check the input common-mode window
The input range includes the negative supply or ground in a typical single-supply application, but does not extend to the positive rail under all normal conditions. Both inputs must be used according to the exact device’s valid range. A five-volt supply does not imply that an input swept from zero to five volts is always a valid linear operating condition.
Allow output headroom and a suitable load
Output swing depends on supply, load current, temperature and variant. The output cannot be assumed to reach the positive supply exactly, and it is not a power driver. A simulation or no-load meter reading is not a guarantee of loaded behavior. Choose a different amplifier when the required output approaches rails that this device cannot support.
Use feedback and unused channels deliberately
A linear circuit needs the intended negative feedback and a valid bias point. An unconnected feedback path can send the output into saturation. Do not leave the unused amplifier’s inputs floating; configure it in a stable documented arrangement within its common-mode and output limits. Local supply bypassing is part of the circuit, not an optional cosmetic component.
Do not treat an op amp as every analog part
An LM358 is not automatically a fast comparator, precision voltage reference or battery-charge controller. Saturation recovery, slew rate, input offset and bias currents can matter. Start with a small low-frequency signal that stays comfortably within the valid range, and measure the complete circuit before assigning an accuracy or speed claim.Newest in the store
Relevant Epro listing
Product information and prices were checked on 19 October 2026. This is a current snapshot, not a historical price associated with the publication timestamp. Stock, accessories and checkout prices can change. Listing claims are not independent performance or authenticity certifications.
| Product | Checked price | Stock |
|---|---|---|
| Op-Amp LM358 IC in Pakistan | PKR 24 | In stock |
Frequently asked questions
Is LM358 rail-to-rail?
Do not assume that. Input and output limitations near the positive rail must be checked for the exact variant and load.
Can I copy LM358B specifications to every LM358?
No. Match the actual manufacturer, suffix and conditions in the datasheet.
Related Epro reading
Review breadboard connections before assembling a prototype. For controller expansion, the Mega 2560 pin guide explains why pin names and electrical limits must be checked together.
Technical references and test limitations
This guide uses the documentation linked below. The procedures are for a controlled, low-voltage learning setup; no independent hands-on test of the particular seller board is claimed. Record the actual part markings, wiring and firmware version before drawing conclusions from a test.