The "INA105KU" is a high-precision instrumentation amplifier, produced by Texas Instruments. It typically comes in a Dual-in-Line Package (DIP) or a Surface-Mount Package (SMD), and the "KU" suffix indicates a specific package code. Below is the detailed explanation of the pin functions, specifications, and FAQs.
Package Details
Package Type: The INA105KU is commonly found in the SOIC-8 package. Pin Count: 8 pins.Pin Function Table for INA105KU
Pin Number Pin Name Function Description 1 V+ Positive Power Supply Pin (typically +5V to +36V) 2 IN- Negative Input Pin (Inverting input for the instrumentation amplifier) 3 IN+ Positive Input Pin (Non-inverting input for the instrumentation amplifier) 4 REF Reference Pin (Used to set the output voltage reference) 5 V- Negative Power Supply Pin (typically -5V to -36V) 6 OUT Output Pin (The output voltage from the instrumentation amplifier) 7 NC No Connection (This pin is not internally connected to anything) 8 RG Gain Resistor Pin (Used to set the gain of the amplifier by connecting an external resistor between this pin and REF pin)Explanation of Each Pin
V+ (Pin 1): This is the positive power supply pin. It connects to the positive voltage supply to power the INA105KU. Typically, this voltage ranges from +5V to +36V.
IN- (Pin 2): The inverting input pin of the instrumentation amplifier. This pin is where the signal from the system is fed in a differential configuration.
IN+ (Pin 3): The non-inverting input pin of the instrumentation amplifier. It also receives the signal in a differential configuration.
REF (Pin 4): This pin is used to set the reference voltage for the output signal. The output of the INA105KU is a differential signal based on the input voltage difference and this reference voltage. This pin provides a reference for the output voltage.
V- (Pin 5): The negative power supply pin. It connects to the negative voltage supply to complete the power requirements for the INA105KU. Typically, this voltage ranges from -5V to -36V.
OUT (Pin 6): This is the output pin where the amplified signal is provided. The output voltage is the amplified difference between the IN+ and IN- inputs, adjusted by the reference voltage (REF).
NC (Pin 7): This pin has no internal connection and does not serve any purpose. It is typically left floating in a circuit design.
RG (Pin 8): This pin is used to set the gain of the instrumentation amplifier. An external resistor can be placed between this pin and the REF pin to adjust the gain of the amplifier. The gain is set using the formula: [ Gain = 1 + \frac{50 kΩ}{RG} ] Where ( RG ) is the resistor value between the RG and REF pins.
20 Frequently Asked Questions (FAQs) for INA105KU
Q1: What is the recommended supply voltage for INA105KU? A1: The INA105KU can operate with a supply voltage range of +5V to +36V on the V+ pin, and -5V to -36V on the V- pin.
Q2: How do I set the gain of the INA105KU? A2: The gain of the INA105KU is set by placing an external resistor between the RG pin (Pin 8) and the REF pin (Pin 4). The gain is calculated as: [ Gain = 1 + \frac{50 kΩ}{R_G} ]
Q3: What is the maximum output voltage swing of the INA105KU? A3: The maximum output voltage swing of the INA105KU is typically within the supply rails, which means it can swing close to the V+ and V- supply voltages but will not reach them entirely.
Q4: What is the common-mode rejection ratio (CMRR) of the INA105KU? A4: The INA105KU has a typical CMRR of 100dB, which means it rejects common-mode signals and amplifies only the differential signal.
Q5: Can I use the INA105KU in single-supply applications? A5: Yes, the INA105KU can be used in single-supply applications, as long as the supply voltage range meets the requirements of the device.
Q6: What is the input impedance of the INA105KU? A6: The input impedance of the INA105KU is very high, typically 10^12 ohms, which makes it suitable for measuring low-current signals.
Q7: How do I connect the REF pin to ground if I don't want a reference voltage? A7: You can connect the REF pin directly to ground if you want the output to be referenced to 0V.
Q8: Is there any internal filtering on the INA105KU? A8: The INA105KU does not have internal filtering, so you may need to add external filtering components depending on your application needs.
Q9: How do I protect the INA105KU from electrostatic discharge (ESD)? A9: You can use external protection diodes or resistors at the input pins to protect the INA105KU from ESD events.
Q10: What is the input voltage range for the INA105KU? A10: The input voltage range for the INA105KU depends on the supply voltage but generally should be within the common-mode range specified in the datasheet.
Q11: Can the INA105KU handle large differential voltages? A11: The INA105KU is designed to handle large differential voltages, but make sure the voltage difference between the input pins (IN+ and IN-) does not exceed the specified limits in the datasheet.
Q12: How do I calculate the output voltage of the INA105KU? A12: The output voltage is calculated as: [ V{out} = Gain \times (V{in+} - V{in-}) + V{REF} ]
Q13: What is the typical output impedance of the INA105KU? A13: The output impedance of the INA105KU is typically low, around 0.2Ω, making it suitable for driving ADCs or other analog devices.
Q14: Is the INA105KU suitable for low-power applications? A14: Yes, the INA105KU is suitable for low-power applications, with a typical supply current of around 1.5mA.
Q15: What type of external components are needed for the INA105KU? A15: The primary external component required is a resistor to set the gain between the RG and REF pins. Additional capacitor s may be used for filtering or stability if required.
Q16: Can the INA105KU be used for audio applications? A16: Yes, the INA105KU can be used in audio applications where high precision and low noise are important.
Q17: How do I select the appropriate gain resistor? A17: To select the appropriate gain resistor, calculate the desired gain and use the formula: [ R_G = \frac{50 kΩ}{Gain - 1} ]
Q18: What is the typical noise performance of the INA105KU? A18: The INA105KU has low noise performance, with a typical noise density of 25nV/√Hz at 1kHz.
Q19: Can I use the INA105KU in a differential measurement setup? A19: Yes, the INA105KU is ideal for differential measurements, such as strain gauge or thermocouple signal conditioning.
Q20: Is the INA105KU RoHS compliant? A20: Yes, the INA105KU is RoHS compliant and meets environmental standards for lead-free soldering.
Conclusion
This detailed explanation includes the pin functions, gain setting mechanism, and answers to common questions about the INA105KU. The part is ideal for high-precision, differential signal applications and provides an easily configurable solution for instrumentation.
