Introduction to LM747
- Designed by National Semiconductor, LM747 is a general-purpose dual operational amplifier integrated chip.
- Two operational amplifiers are incorporated that share common power supply leads and a bias network.
- And these amplifiers are capable of performing two different operations at the same time which makes them a suitable pick for a number of applications. Though these amplifiers share a common bias network, they are completely independent of each other
- As two general-purpose amplifiers are used in this chip, it is used to construct op-amp circuits like differential amplification, comparator, and mathematical operations.
- This device features offset pins which are mainly used to make the output more accurate and efficient.
- It comes with no latch-up when the input common-mode range is exceeded which sets it free from oscillations.
LM747 DatasheetBefore you incorporate this device into your electrical project, it’s better to scan through the datasheet of the component that features the main characteristics of the component. You can download the datasheet of LM747 from the link given below.
LM747 PinoutLM747 incorporates 14 pins on board. The following figure shows the pinout diagram of LM747. The following table details the pin name and pin description of each pin on LM747.
|Pin Description of JRC4558|
|Pin No.||Pin Description||Pin Name|
|1||Inverting input of op-amp 1||1IN-|
|2||A non-Inverting input of op-amp 1||1IN+|
|3||Offset null pin used to remove the offset voltage and control the input voltages for op-amp 1||OFFSET NULL 1|
|4||Common negative supply voltage for both Op-amps||V-|
|5||Offset null pin used to remove the offset voltage and control the input voltages for op-amp 1||OFFSET NULL 2|
|6||The non-Inverting input of op-amp 2||2IN+|
|7||Inverting input of op-amp 2||2IN-|
|8||Offset null pin used to remove the offset voltage and control the input voltages for the op-amp 2||OFFSET NULL 2|
|9||Positive supply voltage for op-amp 2||V2+|
|10||The output pin of the op-amp 2||2OUT|
|12||The output pin of the op-amp 1||1OUT|
|13||Positive supply voltage for op-amp1||V1+|
|14||Offset null pin used to remove the offset voltage and control the input voltages for op-amp 1||OFFSET NULL 1|
- Offset null pins are used to remove the offset voltage and balance the output voltages for both operational amplifiers.
- While pin 11 is not connected. It is not used for any purpose.
LM747 FeaturesThe following are the main features of LM747.
- No latch-up
- Large differential voltage and common mode range
- Low noise interference among op-amps
- Total power dissipation = 800mW
- Differential input voltage = ±30V
- Low power consumption
- Supply voltage Max. = ±22V
- Frequency Compensation not required
- Comes with short-circuit protection
- Common-Mode Rejection Ratio CMRR = 90dB
- Operating temperature range = -55ºC to +125ºC
LM747 ApplicationsThe following are the main applications of LM747.
- Employed in mathematical operations
- Used in amplifiers
- Used in analog circuits
- Used for Measuring instruments
- Incorporated in voltage comparators
- Employed for Industrial applications
- Used in Peak detectors