Overview
The LM567CMX/NOPB, produced by Texas Instruments, is a general-purpose tone decoder integrated circuit. It is designed to provide a saturated transistor switch to ground when an input signal is present within the specified passband. The device utilizes a voltage-controlled oscillator (VCO) and phase-locked loop (PLL) to determine the center frequency of the decoder. External components such as resistors and capacitors are used to set the center frequency, bandwidth, and output delay independently. This flexibility makes the LM567CMX/NOPB versatile for various applications requiring precise frequency detection.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage | 3.5 | 9 | V | |
| Operating Temperature Range | 0 | 70 | °C | |
| Power Dissipation | 1100 | mW | ||
| Input Resistance | 15 | 18 | 20 | kΩ |
| Smallest Detectable Input Voltage | 20 | 22.5 | 25 | mVrms |
| Largest No Output Input Voltage | 10 | 12.5 | 15 | mVrms |
| Largest Simultaneous Outband Signal to Inband Signal Ratio | 6 | 6 | dB | |
| Largest Detection Bandwidth | 10 | 13 | 18 | % of fo |
| Power Supply Current | 11 | 13 | 15 | mA |
Key Features
- Logic compatible output with 100-mA current sinking capability
- Bandwidth adjustable from 0 to 14% of the center frequency
- High rejection of out-of-band signals and noise
- Immunity to false signals
- Highly stable center frequency adjustable from 0.01 Hz to 500 kHz
- Open collector transistor output requiring an external load resistor
- External components for setting center frequency, bandwidth, and output delay
Applications
- Touch-tone decoding
- Precision oscillator
- Frequency monitoring and control
- Wide band FSK demodulation
- Ultrasonic controls
- Carrier current remote controls
- Communications paging decoders
Q & A
- What is the primary function of the LM567CMX/NOPB?
The LM567CMX/NOPB is a general-purpose tone decoder designed to provide a saturated transistor switch to ground when an input signal is present within the specified passband.
- What is the range of the supply voltage for the LM567CMX/NOPB?
The supply voltage range is from 3.5 V to 9 V.
- How is the center frequency of the decoder set?
The center frequency is set by an external timing circuit composed of a capacitor and a resistor.
- What is the typical bandwidth adjustment range for the LM567CMX/NOPB?
The bandwidth can be adjusted from 0 to 14% of the center frequency.
- What type of output does the LM567CMX/NOPB provide?
The device provides an open collector transistor output that requires an external load resistor.
- What are some common applications of the LM567CMX/NOPB?
Common applications include touch-tone decoding, precision oscillators, frequency monitoring and control, wide band FSK demodulation, ultrasonic controls, and communications paging decoders.
- How is the detection bandwidth affected by input voltage levels?
The detection bandwidth varies based on the input voltage levels (Vi), with different behaviors for Vi < 200 mVRMS and Vi > 200 mVRMS.
- What is the recommended operating temperature range for the LM567CMX/NOPB?
The recommended operating temperature range is from 0°C to 70°C.
- How should the power supply be decoupled for the LM567CMX/NOPB?
A well-regulated power supply is recommended, and a decoupling capacitor should be placed as close as possible to the VCC pin.
- What are the package options available for the LM567CMX/NOPB?
The device is available in SOIC (8-pin) and PDIP (8-pin) packages.
