How to get all children product from parent configurable product in magento2

You have to just keep below code inside block file and call function inside your template,

protected $productFactory;
protected $dataObjectHelper;
protected $productRepository;

public function __construct(        
    \Magento\Framework\View\Element\Template\Context $context,                   
    \Magento\Catalog\Api\Data\ProductInterfaceFactory $productFactory,  
    \Magento\Catalog\Api\ProductRepositoryInterface $productRepository,    
    \Magento\Framework\Api\DataObjectHelper $dataObjectHelper,
    array $data = [] 
){      
    $this->productFactory = $productFactory;      
    $this->productRepository = $productRepository;        
    $this->dataObjectHelper = $dataObjectHelper;
    parent::__construct($context,$data);    
}


     public function getConfigChildProductIds($id){
            $product = array();
            if(is_numeric($id)){           
                $product = $this->productRepository->getById($id); 
            }else{
                return;
            } 

            if(!isset($product)){
                return;
            }

            if ($product->getTypeId() != \Magento\ConfigurableProduct\Model\Product\Type\Configurable::TYPE_CODE) {
                return [];
            }

            $storeId = $this->_storeManager->getStore()->getId();

            $productTypeInstance = $product->getTypeInstance();
            $productTypeInstance->setStoreFilter($storeId, $product);
            $usedProducts = $productTypeInstance->getUsedProducts($product);
            $childrenList = [];       

            foreach ($usedProducts  as $child) {
                $attributes = [];
                $isSaleable = $child->isSaleable();

                //getting in-stock product
                if($isSaleable){
                    foreach ($child->getAttributes() as $attribute) {
                        $attrCode = $attribute->getAttributeCode();
                        $value = $child->getDataUsingMethod($attrCode) ?: $child->getData($attrCode);
                        if (null !== $value && $attrCode != 'entity_id') {
                            $attributes[$attrCode] = $value;
                        }
                    }

                    $attributes['store_id'] = $child->getStoreId();
                    $attributes['id'] = $child->getId();
                    /** @var \Magento\Catalog\Api\Data\ProductInterface $productDataObject */
                    $productDataObject = $this->productFactory->create();
                    $this->dataObjectHelper->populateWithArray(
                        $productDataObject,
                        $attributes,
                        '\Magento\Catalog\Api\Data\ProductInterface'
                    );
                    $childrenList[] = $productDataObject;
                }
            }

            $childData = array();
            foreach($childrenList as $child){
                $childData[] = $child;
            }

            return $childData;
        }

// Inside template file call ,


 $productId = 10 //parent product id..
 $childObj = $block->getConfigChildProductIds($productId);
    foreach ($childObj as $child){                 
       $getChildId[] = $child->getData();
    }
    echo "<pre>";print_r($getChildId);