What is JRC4558 Op Amp : Pin Configuration & Its Applications

A Japan Radio Company designed a dual operational amplifier called JRC4558 with bipolar transistors constructed and compensated internally in a single silicon chip. In 1974, Raytheon Semiconductors developed the first JRC4558 dual op-amp. It is employed in pedal circuit designs, sample & hold amplifiers due to its better input impedance of 5 MΩ, high voltage gain of 100dB, and better 1.7V/µs slew rate. This article gives a brief description of a JRC4558 Op-Amp with pin configuration, circuit diagram, technical specifications, applications, and alternatives.

What is JRC4558 Op-Amp?

A general-purpose 8-pin dual operational amplifier available with good input impedance and high voltage gain is known as JRC4558 Op-Amp. It is a silicon monolithic integrated chip available in different packages like SOP and DIP. It is extremely used in pedal circuits because it gives a high voltage gain of 100dB, 5MΩ of input impedance with a power supply range of ±4V to 18V. It became popular among engineers and hobbyists due to its high performance and low cost.

It is an 8-pin silicon chip, in which pin 8 is for positive voltage supply and pin 4 is for negative power supply. Pins 1 and 7 are the output terminals of the two operational amplifiers, which are integrated inside the chip. Pins 2 and 6 are the inverting input terminals with -V of both operational amplifiers. While pins 3 and 5 are the non-inverting input terminals with +Vof both operational amplifiers.

The two operational amplifiers integrated into the device are independent and internally compensated op-amps with better input impedance. These can be operated with a single power supply over wide voltage ranges. They are different from ideal op-amps because they have a voltage gain of only 100dB when compared to the infinite voltage gain of an ideal op-amp. The rate of change of output voltage gives the maximum slew rate of 1.7V/µs.

The output voltage produced by this op-amp is very high when compared to the potential difference in the input voltage. It is used as a general-purpose operational amplifier in various electronic circuit applications, comparators, differential amplification, and mathematical operations with only a positive power supply of +5V without any requirement of a negative power supply of -5V.

JRC4558 Op-Amp Pin Configuration/Pin Diagram:

The JRC4558 is an 8-pin dual op-amp used for general purpose applications. This section gives details of pin configuration/pin diagram of the JRC4558 op-amp that contains two operational amplifiers inside the chip connected as shown in the figure below.

Pin 1: (OUTPUT A): This pin represents the output terminal of the first op-amp (A).

Pin 2: (INV. INPUT A): This pin represents the inverting input terminal of the first op-amp (A).

Pin 3: (NON-INV. INPUT A): This pin represents the non-inverting input terminal of the first op-amp (A).

Pin 4: (POWER (-Vs)): This pin represents the negative voltage supply of the op-amp.

Pin 5: (NON.INV INPUT B)): This pin represents the non-inverting input terminal of the second op-amp.

Pin 6: (INV INPUT B): This pin represents the inverting input terminal of the second op-amp.

Pin 7: (OUTPUT B): This pin represents the output terminal of the second op-amp.

Pin 8: (POWER (+Vs)): This pin represents the positive voltage or power supply given to the op-amp.

Alternatives of JRC4558 Op-Amp:

The replacement or alternatives of the JRC4558 op-amp are LM158A, LM158, LM358A, LM358, LM2904Q, LM2904, LM747, and LM4558 op-amps.

Features & Specifications:

The features & technical specifications of the JRC4558 op-amp include the following.

• The range of supply voltage of a JRC4558 is ±5V to ±15V.
• The bandwidth is 3MHz.
• The internal circuit requires two operational amplifiers.
• It is an 8-pin integrated circuit.
• The maximum operating temperature is 70°C.
• The minimum operating temperature is 0°C.
• Its slew rate is 1.7V/microseconds.
• It is manufactured in 8-pin SOP and DIP packages.
• No requirement of frequency compensation.
• No latch-up.
• Differential voltage range and large common mode.
• Provides tracking of a parameter over the specified temperature range.
• Phase and gain match between the amplifiers.
• Low noise input transistors.
• Compatible with LM358 or MC1458.

Circuit Diagram/How to use JRC4558 Op-Amp?

The JRC4558 is used as a general-purpose op-amp amplification, differentiation, and mathematical and comparator circuit operations. It is designed for single voltage systems, transducers, amplifiers, dc amplification blocks, and various analog circuits.

Consider the circuit diagram of the JRC4558 op-amp shown below that illustrates how to use the JRC4558 op-amp in a differential amplifier circuit. Consider an example circuit shown below for converting single-ended input to differential output. The requirements of the circuit design are,

• 15V supply voltage
• 12V reference voltage
• 2V to 10V input voltage
• Differential output ±8V

Make the connections as per the circuit diagram shown above to convert a single-ended input voltage of 2V – 10V to a differential output voltage of ±8V with a supply voltage of 15V. To maximize linearity, the output is limited intentionally.

The circuit is designed with two amplifiers, in which the first one acts as a buffer amplifier with an output voltage of Vout+ and the second amplifier inverts the input voltage and generates the output voltage Vout- by adding the reference voltage 12V. The output voltage signals of amplifiers (Vout+ and Vout-) range from 2V to 10V. The difference between the Vout+ and Vout- gives the differential output voltage Vdiff.

From the circuit, the equations for output voltages generated by the amplifiers are given as,

Vout+ = Vin ——> eq 1

Vout- = Vref x (R4/(R3+R4)) x (1+(R2/R1)) – Vin x (R2/R1) ——-> eq 2

Where ‘Vout+’ is the output signal generated by the buffer (first) amplifier.

‘Vi’n is the input voltage single-ended input voltage signal given to the buffer amplifier.

‘Vout-‘ is output signal generated by the 2nd amplifier

‘Vref’ is the reference voltage

The difference between the single-ended output signals Vout+ and Vout- of the amplifiers gives the differential output signal Vdiff.

From eq 1 & 2 we get,

Vdiff = Vout+ – Vout- ——> eq 3

Where Vout+ = Vin —–> eq 4

If R1= R2 and R3=R4 then

Vout- =Vref – Vin ——> eq 5

By substituting the eq 4 & 5 in eq 3 we get

Vdiff = 2 X Vin – Vref —–> eq 6

From this, the common-mode reference voltage is given as the half of reference voltage Vref,

Vcm = ((Vout+ – Vout-)/2) = ½Vref

Where to use/Applications of JRC4558 Op-Amp:

The applications of the JRC4558 op-amp are listed below

• Used in automobiles and signal amplifiers with ground reference.
• Used in hold and sample amplifiers.
• Used in portable and photocurrent instrumentation.
• Employed in intrusion alarm systems.
• Used in function generators.
• Used in comparators.
• Used in instrumentation amplifiers.
• Used in timers and multivibrators.
• Used in DVD players, recorders, and Pro audio mixers.

Please refer to this link to know more about JRC4558 Op-Amp Datasheet.

Thus, this is all about an overview of the JRC4558 op-amp. Thus, the two onboard operational amplifiers used in the device helps to perform any two operations simultaneously. It is used as either an individual device or a component in complex electronic circuits, scientific devices, consumer and industrial applications. Here is a question for you, “What are the features of the JRC4558 op-amp?”