NXP Semiconductors 74HC4046AD,652

Overview

74HC4046AD,652 from Nexperia is a high-speed CMOS phase-locked loop (PLL) IC with integrated linear voltage-controlled oscillator (VCO) and three selectable phase comparators (XOR, edge-triggered J-K, and RS flip-flop). It operates from 3.0 V to 6.0 V (VCO section), delivers up to 17 MHz typical center frequency at 4.5 V, and supports FM demodulation, frequency synthesis, and motor-speed control.

For engineers reviewing the 74HC4046AD,652 datasheet, 74HC4046AD,652 pinout, 74HC4046AD,652 application, or 74HC4046AD,652 equivalent, key selection factors include VCO linearity (±0.4% relative frequency variation), low temperature drift (0.15%/K), triple comparator architecture, inhibit-controlled standby power, and SO16 package compatibility with standard PCB layouts.

Technical Context

The 74HC4046AD,652 implements a second-order PLL using external R1/R2 and C1 components to set VCO frequency range and offset. Its VCO features high input impedance and buffered DEM_OUT that mirrors VCO_IN voltage-enabling accurate low-pass filter design without loading effects.

All three phase comparators share a common signal input amplifier and comparator input. PC1 (XOR) requires 50% duty-cycle inputs for maximum lock range; PC2 (J-K) and PC3 (RS) are edge-triggered and tolerant of arbitrary duty cycles, with PC2 providing 3-state output and locked-status indication via PCP_OUT.

Key Specifications

Pinout & Package

74HC4046AD,652 is supplied in SO16 (SOT109-1) plastic small outline package, 16 leads, 3.9 mm body width.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar phase-locked loop applications.

Compared with CD74HC4046M96 and MC14046BDG, the 74HC4046AD,652 offers superior VCO linearity (±0.4% vs. ±1.5%), lower temperature drift (0.15%/K vs. 0.3%/K), and integrated DEM_OUT buffering - reducing BOM count and improving closed-loop stability in precision frequency control.

Availability

74HC4046AD,652 is available at Aetrix Electronics and suitable for FM demodulation, frequency synthesis, and motor-speed control applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for 74HC4046AD,652 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Nexperia is a global semiconductor expert delivering high-performance logic, analog, and MOSFET solutions with focus on efficiency, reliability, and sustainability.

The 74HC4046AD,652 belongs to Nexperia's 74HC logic family, engineered for high-speed, low-power phase-locked loop applications in industrial, automotive, and communications systems where precision frequency control and thermal stability are essential.

FAQ

What is the maximum operating frequency of the VCO in the 74HC4046AD,652?

The 74HC4046AD,652 VCO achieves a typical center frequency of 17 MHz at VCC = 4.5 V with R1 = 3 kΩ and C1 = 40 pF. Under optimized conditions (VCC = 6.0 V), it reaches 21 MHz. This frequency is set externally by R1, R2, and C1 values and remains stable across temperature due to its 0.15 %/K drift coefficient. The 74HC4046AD,652 datasheet confirms these values in Table 7 under dynamic characteristics.

How does the DEM_OUT pin function in the 74HC4046AD,652?

The DEM_OUT pin on the 74HC4046AD,652 provides a buffered, unity-gain replica of the VCO_IN voltage - unlike conventional designs where DEM_OUT lags by one threshold voltage. This eliminates feedback path errors and allows direct connection to low-pass filters without loading. When unused, DEM_OUT must be left open; if used, a series resistor (50–300 kΩ) is required to ground. This behavior is explicitly defined in Section 8.1 of the 74HC4046AD,652 datasheet.

Which phase comparator should I use for data synchronization with noisy input signals?

For data synchronization with noisy inputs, Phase Comparator 1 (PC1) is recommended in the 74HC4046AD,652. Its XOR architecture maintains lock even with high input noise and harmonically rich signals, and its capture range can match the lock range when paired with an appropriate low-pass filter. PC1 requires 50% duty-cycle inputs, so ensure signal conditioning if needed. This guidance is derived from Figure 5 and Section 8.2.1 of the 74HC4046AD,652 functional description.

Can the 74HC4046AD,652 operate with separate supply voltages for the VCO and digital sections?

No - the 74HC4046AD,652 uses a single VCC pin (pin 16) powering both digital logic and VCO sections. However, the VCO section is specified for 3.0–6.0 V operation while the digital section functions down to 2.0 V, allowing safe operation at 3.0–6.0 V where both domains are fully compliant. Supply decoupling is critical: a 100 nF ceramic capacitor must be placed close to VCC and GND pins to prevent VCO instability. This constraint is stated in Table 4 (Recommended Operating Conditions) of the 74HC4046AD,652 datasheet.

What external components are required to configure the VCO in the 74HC4046AD,652?

The 74HC4046AD,652 VCO requires at minimum one external capacitor C1 (40–no limit pF) connected between pins C1A (6) and C1B (7), and one external resistor R1 (3–300 kΩ) from pin R1 (11) to GND. Optionally, R2 (3–300 kΩ) from pin R2 (12) to GND adds frequency offset. The parallel value of R1 and R2 must exceed 2.7 kΩ, and values >10 kΩ yield optimum linearity. These requirements are detailed in Section 8.1 and Table 5 of the 74HC4046AD,652 datasheet.