bq2050hsn is 'HDQ'or'DQ'

Hi,

We are using bq2050h in our application, recently we bought some bq2050h but they did not work properly.On checking we found that some of the IC's are 'DQ' version while some are 'HDQ' version .

But both have same code printed on them that is "bq2050hsn-09A40K8D336" .

Can someone give some clarification about this problem?