Traitement en cours

Veuillez attendre...

Paramétrages

Paramétrages

Aller à Demande

1. US6353403 - Fast ramping of control voltage with enhanced resolution

Office États-Unis d'Amérique
Numéro de la demande 09544583
Date de la demande 06.04.2000
Numéro de publication 6353403
Date de publication 05.03.2002
Numéro de délivrance 6353403
Date de délivrance 05.03.2002
Type de publication B1
CIB
H03M 1/66
HÉLECTRICITÉ
03CIRCUITS ÉLECTRONIQUES FONDAMENTAUX
MCODAGE, DÉCODAGE OU CONVERSION DE CODE, EN GÉNÉRAL
1Conversion analogique/numérique; Conversion numérique/analogique
66Convertisseurs numériques/analogiques
H03L 3/00
HÉLECTRICITÉ
03CIRCUITS ÉLECTRONIQUES FONDAMENTAUX
LCOMMANDE AUTOMATIQUE, DÉMARRAGE, SYNCHRONISATION OU STABILISATION DES GÉNÉRATEURS D'OSCILLATIONS OU D'IMPULSIONS ÉLECTRONIQUES
3Démarrage des générateurs
CPC
H03L 3/00
HELECTRICITY
03BASIC ELECTRONIC CIRCUITRY
LAUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
3Starting of generators
Déposants Ericsson Inc.
Inventeurs Williams, Rodney Owen
Mandataires Coats & Bennett, P.L.L.C.
Données relatives à la priorité 09544583 06.04.2000 US
Titre
(EN) Fast ramping of control voltage with enhanced resolution
Abrégé
(EN)

A logic circuit for generating a control voltage includes a ramp DAC and a main DAC. When the control voltage is needed, such as when an associated crystal oscillator is being “turned on,” an input reference voltage is supplied to both the ramp DAC and the main DAC. The ramp DAC generates an output based on the input reference voltage and L supplied control bits for a (preferably short) ramp time period. The output from the ramp DAC is fed to a filter circuit that includes a capacitor to charge the capacitor and the control voltage is generated at least in part from the ramp DAC output as filtered by the capacitor. When the ramp period ends, the state of the input reference voltage is changed and the output from the main DAC, based on the changed input reference voltage and N control bits, is input to the filter. Such a two DAC arrangement allows for a shorter time constant circuit to be employed in association with the ramp DAC and a longer time constant circuit to be employed in association with the main DAC, allowing for quick ramp up of the control voltage.

Également publié en tant que