Features
• Operating Frequency Range
- Up to 18MHz (Typ) at VCC = 5V
- Minimum Center Frequency of 12MHz at VCC = 4.5V
• 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 for Low
Standby Power Consumption
• Minimal Frequency Drift
• Operating Power Supply Voltage Range
- VCO Section . . . . . . . . . . . . . . . . . . . . . . . . . . 3V to 6V
- Digital Section . . . . . . . . . . . . . . . . . . . . . . . . 2V to 6V
• Fanout (Over Temperature Range)
- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
• Wide Operating Temperature Range . . . -55oC to 125oC
• Balanced Propagation Delay and Transition Times
• Significant Power Reduction Compared to LSTTL
Logic ICs
• HC Types
- 2V to 6V Operation
- High Noise Immunity: NIL = 30%, NIH = 30% of VCC
at VCC = 5V
• HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
VIL= 0.8V (Max), VIH = 2V (Min)
- 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

Description
The ’HC4046A and ’HCT4046A are high-speed silicon-gate
CMOS devices that are pin compatible with the CD4046B of
the “4000B” series. They are specified in compliance with
JEDEC standard number 7.
The ’HC4046A and ’HCT4046A are phase-locked-loop
circuits that contain a linear voltage-controlled oscillator
(VCO) and three different phase comparators (PC1, PC2 and
PC3). A signal input and a comparator input are common to
each comparator.
The signal input can be directly coupled to large voltage
signals, or indirectly coupled (with a series capacitor) to small
voltage signals. A self-bias input circuit keeps small voltage
signals within the linear region of the input amplifiers. With a
passive low-pass filter, the 4046A forms a second-order loop
PLL. The excellent VCO linearity is achieved by the use of
linear op-amp techniques.