HEF4046B(2016) Ver la hoja de datos (PDF) - NXP Semiconductors.

Número de pieza

componentes Descripción

Fabricante

HEF4046B
(Rev.:2016)

Phase-locked loop

NXP Semiconductors. 

Nexperia

HEF4046B

Phase-locked loop

5.2 Pin description

Table 2. Pin description

Symbol

Pin

PCP_OUT

1

PC1_OUT

2

COMP_IN

3

VCO_OUT

4

INH

5

C1A

6

C1B

7

VSS

8

VCO_IN

9

SF_OUT

10

R1

11

R2

12

PC2_OUT

13

SIG_IN

14

ZENER

15

VDD

16

6. Functional description

Description

phase comparator pulse output

phase comparator 1 output

comparator input

VCO output

inhibit input

capacitor C1 connection A

capacitor C1 connection B

ground supply voltage

VCO input

source-follower output

resistor R1 connection

resistor R2 connection

phase comparator 2 output

signal input

Zener diode input for regulated supply

supply voltage

6.1 VCO control

The VCO requires an external capacitor (C1) and resistor (R1) with an optional resistor

(R2). Resistor R1 and capacitor C1 determine the frequency range of the VCO, while

resistor R2 enables the VCO to have a frequency off-set if required. The high input

impedance of the VCO simplifies the design of low-pass filters; it permits the designer a

wide choice of resistor/capacitor ranges. In order not to load the low-pass filter, a

source-follower output of the VCO input voltage is provided at SF_OUT (pin 10). If this is

used, a load resistor (RL) should be connected from SF_OUT to VSS; if unused, SF_OUT

should be left open. The VCO output (pin 4) can either be connected directly to the

comparator input COMP_IN (pin 3) or via a frequency divider. A LOW-level at the inhibit

input INH_IN (pin 5) enables the VCO and the source follower, while a HIGH-level turns

both off to minimize standby power consumption.

6.2 Phase comparators

The phase-comparator signal input SIG_IN (pin 14) can be direct-coupled, provided the

signal swing is between the standard HE4000B family input logic levels. The signal must

be capacitively coupled to the self-biasing amplifier at the signal input with smaller swings.

Phase comparator 1 is an EXCLUSIVE-OR network. The signal and comparator input

frequencies must have a 50 % duty factor to obtain the maximum lock range. The average

output voltage of the phase comparator is equal to 0.5VDD when there is no signal or noise

at the signal input. The average voltage to the VCO input VCO_IN is supplied by the

low-pass filter connected to the output of phase comparator 1. This also causes the VCO

to oscillate at the center frequency (f0). The frequency capture range (2fC) is defined as

HEF4046B

Product data sheet

All information provided in this document is subject to legal disclaimers.

Rev. 6 — 24 March 2016

© Nexperia B.V. 2017. All rights reserved

3 of 19

Share Link: