MC1648M - Voltage-Controlled Oscillator | Motorola
MPN： MC1648M ✗ 停產MC1648M 概覽
A voltage-controlled oscillator, or VCO, generates an output signal whose frequency varies with an applied control voltage. The MC1648 belongs to the broader clock and timing IC family, where it provides a tunable oscillator rather than a fixed-frequency clock. Its external tank circuit allows the designer to select inductance and capacitance for the target operating range, while the control voltage provides fine frequency adjustment. This architecture is useful in FM transmitters, frequency synthesizers, clock-generation circuits, and frequency-discriminator systems.
The main verified technical characteristics are its external parallel LC-tank requirement and the recommended tank quality factor of QL at least 100 for maximum performance. The device also supports voltage-variable operation when a varactor diode is incorporated into the tank circuit. The supplied search results identify MC1648M as a Motorola voltage-controlled oscillator and associate it with a DIP-style MC1648 package family, but the detailed electrical ratings, frequency limits, supply voltage, output characteristics, pin names, and package dimensions were not included in the verified dataset.
For design implementation, the external tank components should be placed close to the oscillator pins and selected for the intended frequency range. Component tolerance, parasitic capacitance, and inductor Q can shift the operating frequency. The control-voltage range and permitted control-voltage slew rate should be verified in the manufacturer datasheet before relying on the part for precision frequency control.
Typical uses include FM radio modulation, tone generation, frequency conversion, and tunable clock sources. The MC1648M is most appropriate when an external LC network and application-specific frequency calibration are acceptable. Modern designs may instead choose a higher-integration oscillator when smaller size, digital calibration, or a specified phase-noise performance is required. This page combines the verified Motorola MC1648 tank-circuit requirements, distributor availability information, pricing context, and practical selection guidance.
The verified distributor listing shows MC1648M in stock at LCSC with a starting price of $1.0043. Pricing and inventory should be checked with the authorized supplier before purchase, especially because legacy semiconductor availability can vary by package, region, and production status.
直接替換替代品，適用於 MC1648M — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此產品無可直接替換的替代品。
申請替代品MC1648M 規格
| Product Type | Voltage-controlled oscillator |
| Manufacturer | Motorola |
| Required External Tank | Parallel LC tank circuit |
| Tank Components | Inductor and capacitor |
| Recommended Tank Quality Factor | QL greater than or equal to 100 |
| Voltage-Variable Operation | Supported with varactor diode in tank circuit |
MC1648M standard 腳位配置指南
MC1648M（standard 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： MC1648M.
請參閱 資料表 以查看完整腳位配置。
典型應用
MC1648M 適用於 6 應用s: FM Transmitter Modulation, Frequency Synthesizer Clock, Tone Generation and Frequency Control, Frequency Discriminator and Detection, RF Signal Source, Educational and Laboratory Oscillator Circuits.
FM Transmitter Modulation
The MC1648M fits FM signal generation because its voltage-controlled oscillator function allows the output frequency to be varied by a control signal. In an FM transmitter, a varactor diode can be placed in the external parallel LC tank so that modulation voltage changes the tank capacitance. The verified MC1648 documentation identifies QL greater than or equal to 100 as the recommended tank condition for maximum performance. The design must confirm modulation linearity, control-voltage range, carrier frequency, and allowable distortion before production.
推薦
Frequency Synthesizer Clock
The MC1648M can provide the tunable oscillator element in a frequency-synthesis or clock-generation design. Its external LC tank gives the engineer direct control over the nominal resonant frequency, while a varactor diode supplies voltage-based fine tuning. Compared with a fully integrated clock generator, this architecture offers greater circuit visibility but requires careful layout and component selection. Designers should verify startup, tuning range, temperature stability, and output waveform using the complete manufacturer data.
推薦
Tone Generation and Frequency Control
A voltage-controlled oscillator is useful for tone generators and frequency-control test fixtures because the control voltage can move the operating point without changing the external tank in discrete steps. The MC1648M requires an external parallel tank, and the verified documentation notes that a varactor diode can provide a voltage-variable input. The circuit is appropriate when a tunable analog oscillator and external component adjustment are preferred over a digitally programmed clock. Validate frequency accuracy and temperature behavior in the finished enclosure.
推薦
Frequency Discriminator and Detection
The MC1648M can serve as the tunable oscillator in frequency-discriminator and signal-detection circuits where an input frequency must be compared with a controllable reference. A varactor-tuned tank lets the control loop adjust the oscillator over its usable range. The verified external-tank requirement makes component parasitics and layout important, particularly when small frequency shifts must be detected. Engineers should establish sensitivity and stability from the complete oscillator specification rather than assuming performance from the tank requirement alone.
推薦
RF Signal Source
The MC1648M may be used in a low-complexity RF signal source when the required operating frequency and output characteristics are compatible with the MC1648 family. The external inductor-capacitor network enables tuning around a selected center frequency, and the varactor option provides voltage control. For RF layouts, keep the resonant network compact, minimize parasitic capacitance, and use a controlled ground return. The verified dataset does not specify RF output power or frequency limits, so these must be confirmed before selecting the device.
推薦
Educational and Laboratory Oscillator Circuits
The MC1648M is suitable for laboratory and educational experiments that demonstrate voltage-controlled oscillator behavior, resonant tanks, varactor tuning, and frequency adjustment. Its external LC network makes the resonant elements visible to the learner and allows direct experimentation with inductor and capacitor values. The verified documentation recommends a tank quality factor of QL greater than or equal to 100 for maximum performance. Use current datasheets and appropriate instrumentation when measuring frequency, amplitude, and control sensitivity.
推薦
推薦產品摘要
工程參考資料，適用於 MC1648M — 比較、設計指引及合規資訊。
選型指南
主要差異化特點
- External parallel LC architecture (對比[DATA_NEEDED: compared part])
- Tank-quality guidance (對比[DATA_NEEDED: compared part])
- Distributor availability signal (對比[DATA_NEEDED: compared part])
設計說明
Place the inductor and capacitor that form the external parallel tank as close as practical to the oscillator pins. Minimize trace length and loop area because parasitic inductance and capacitance can shift the resonant frequency. Use a stable ground reference and avoid routing sensitive tank nodes beneath noisy digital or switching circuitry. The verified MC1648 documentation emphasizes an external parallel tank and recommends QL greater than or equal to 100 for maximum performance.
If a varactor diode provides voltage-variable control, keep its control connection and tank layout electrically clean and decouple supply pins according to the complete manufacturer guidance. The varactor’s capacitance-voltage curve, leakage, and bias polarity determine usable tuning range. Do not assume the control voltage is safe for the diode or that the oscillator has unlimited tuning bandwidth; verify both against the MC1648 datasheet.
Do not treat the external LC tank as a cosmetic detail. Inductor tolerance, capacitor tolerance, diode capacitance, PCB parasitics, and temperature can all move the oscillator frequency. Establish the nominal tank values from the target frequency, then validate tuning range and stability across temperature and supply conditions. The available data does not provide MC1648M frequency limits, so use the manufacturer datasheet before selecting final values.
合規資訊
The supplied verified data contains product listings, a datasheet reference, tank-circuit guidance, stock information, and a starting price, but no compliance declarations.