Overview
The CD74HC4046A is a high-speed silicon-gate CMOS phase-locked-loop (PLL) circuit produced by Texas Instruments. It is pin compatible with the CD4046B of the '4000B' series and is specified in compliance with JEDEC standard number 7. This device contains a linear voltage-controlled oscillator (VCO) and three different phase comparators (PC1, PC2, and PC3), making it versatile for various applications.
Key Specifications
| Parameter | Description |
|---|---|
| Operating Frequency Range | Up to 18MHz (Typ) at VCC = 5V, Minimum Center Frequency of 12MHz at VCC = 4.5V |
| Phase Comparators | Choice of Three: EXCLUSIVE-OR, Edge-Triggered JK Flip-Flop, Edge-Triggered RS Flip-Flop |
| VCO Frequency Linearity | Excellent VCO frequency linearity |
| VCO-Inhibit Control | For ON/OFF keying and low standby power consumption |
| Operating Power Supply Voltage Range | VCO Section: 3V to 6V, Digital Section: 2V to 6V |
| Operating Temperature Range | -55°C to 125°C |
| Package | SOIC (D) with 16 pins |
| Fanout | Standard Outputs: 10 LSTTL Loads, Bus Driver Outputs: 15 LSTTL Loads |
Key Features
- High-speed silicon-gate CMOS technology
- Choice of three phase comparators: EXCLUSIVE-OR, Edge-Triggered JK Flip-Flop, Edge-Triggered RS Flip-Flop
- Excellent VCO frequency linearity
- VCO-Inhibit control for ON/OFF keying and low standby power consumption
- Minimal frequency drift
- Wide operating temperature range: -55°C to 125°C
- Balanced propagation delay and transition times
- Significant power reduction compared to LSTTL logic ICs
- High noise immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5V
- CMOS input compatibility, IL ≤ 1µA at VOL, VOH
Applications
- FM modulation and demodulation
- Frequency synthesis and multiplication
- Frequency discrimination
- Tone decoding
- Data synchronization and conditioning
- Voltage-to-frequency conversion
- Motor-speed control
Q & A
- What is the operating frequency range of the CD74HC4046A?
The operating frequency range is up to 18MHz (Typ) at VCC = 5V, with a minimum center frequency of 12MHz at VCC = 4.5V.
- What types of phase comparators are available in the CD74HC4046A?
The device includes three phase comparators: EXCLUSIVE-OR, Edge-Triggered JK Flip-Flop, and Edge-Triggered RS Flip-Flop.
- What is the VCO-Inhibit control used for?
The VCO-Inhibit control is used for ON/OFF keying and to achieve low standby power consumption.
- What is the operating power supply voltage range for the VCO and digital sections?
The VCO section operates from 3V to 6V, and the digital section operates from 2V to 6V.
- What is the operating temperature range of the CD74HC4046A?
The operating temperature range is -55°C to 125°C.
- What is the fanout capability of the CD74HC4046A?
The standard outputs can drive up to 10 LSTTL loads, and the bus driver outputs can drive up to 15 LSTTL loads.
- What are some common applications of the CD74HC4046A?
Common applications include FM modulation and demodulation, frequency synthesis and multiplication, frequency discrimination, tone decoding, data synchronization and conditioning, voltage-to-frequency conversion, and motor-speed control.
- Is the CD74HC4046A compatible with other CMOS devices?
- How does the CD74HC4046A achieve excellent VCO frequency linearity?
The excellent VCO frequency linearity is achieved by the use of linear op-amp techniques.
- What is the significance of the self-bias input circuit in the CD74HC4046A?
The self-bias input circuit keeps small voltage signals within the linear region of the input amplifiers.
- Can the CD74HC4046A be used in high-noise environments?
