Overview
The LMC567CMX/NOPB is a low-power, general-purpose tone decoder produced by Texas Instruments. It is functionally similar to the industry standard LM567 but offers several improvements, including lower power consumption and a wider supply voltage range. The device consists of a voltage-controlled oscillator (VCO), quadrature dividers, phase and amplitude detectors, and a phase-locked loop (PLL) that locks onto an input signal frequency within the VCO's control range. This makes it suitable for various applications requiring tone decoding and frequency monitoring.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 2 | 5 | 9 | V |
| Input Frequency (FIN) | 1 Hz | 500 kHz | ||
| Operating Temperature (TA) | -25 | 125 | °C | |
| Input Voltage (IN) | 2 Vp-p | |||
| Output Current (OUT) | 30 mA | |||
| Package Dissipation | 500 mW | |||
| Junction-to-Ambient Thermal Resistance (RθJA) | 111.8 °C/W |
Key Features
- Low supply current drain: The device operates with a nominal supply current of 800 µA.
- Wide supply voltage range: The LMC567 can operate with supply voltages from 2 V to 9 V.
- High oscillator stability: The VCO and PLL ensure high stability and accuracy in frequency locking.
- Ground-referenced input: The input pin is internally ground-referenced, allowing for direct coupling of signals centered on 0 V.
- Hysteresis added to amplitude comparator: This feature helps in rejecting out-of-band signals and noise.
- 20 mA output current capability: The device can handle up to 20 mA of output current.
- No increase in current with output activated: The output switch does not require additional supply current to activate.
Applications
- Touch-Tone Decoding: Suitable for decoding touch-tone signals in telecommunication systems.
- Precision Oscillators: Can be used to create precise oscillators due to its stable VCO.
- Frequency Monitoring and Control: Useful in applications requiring frequency monitoring and control.
- Wide-Band FSK Demodulation: Can be used for demodulating wide-band frequency-shift keying (FSK) signals.
- Ultrasonic Controls: Applicable in ultrasonic control systems.
- Carrier Current Remote Controls: Used in remote control systems that operate over carrier currents.
- Communications Paging Decoders: Suitable for decoding signals in communication paging systems.
Q & A
- What is the supply voltage range of the LMC567CMX/NOPB?
The supply voltage range is from 2 V to 9 V. - What is the maximum input frequency the LMC567CMX/NOPB can handle?
The device can handle input frequencies up to 500 kHz. - How much output current can the LMC567CMX/NOPB handle?
The device can handle up to 20 mA of output current. - Does the output switch require additional supply current to activate?
No, the output switch does not require additional supply current to activate. - What is the typical supply current of the LMC567CMX/NOPB?
The typical supply current is 800 µA. - What are the key components required to set up the oscillator in the LMC567CMX/NOPB?
The oscillator requires timing resistor (Rt) and timing capacitor (Ct) connected to pins 5 and 6 of the IC. - How does the LMC567CMX/NOPB reject out-of-band signals and noise?
The device has hysteresis added to the amplitude comparator, which helps in rejecting out-of-band signals and noise. - What are some common applications of the LMC567CMX/NOPB?
Common applications include touch-tone decoding, precision oscillators, frequency monitoring and control, wide-band FSK demodulation, ultrasonic controls, carrier current remote controls, and communications paging decoders. - What is the operating temperature range of the LMC567CMX/NOPB?
The operating temperature range is from -25°C to 125°C. - How should the power supply be decoupled for the LMC567CMX/NOPB?
A proper decoupling capacitor, typically a 0.1 µF ceramic capacitor with low ESR, should be placed as close as possible to the VCC pin.
