How to emit an event in angular from parent to child

child.ts

private eventsSubscription: any

@Input() events: Observable<void>;

ngOnInit(){
  this.eventsSubscription = this.events.subscribe(() => doSomething())
}

ngOnDestroy() {
  this.eventsSubscription.unsubscribe()
}

parent.html

<child [events]="eventsSubject$"> </child>    

parent.ts

private eventsSubject: Subject<void> = new Subject<void>();
private eventsSubject$ = this.tabChanged.asObservable();

emitEventToChild() {
  this.eventsSubject.next()
}