No, it is a type of democracy better described as a constitutional republic.
Here's the way I think of it - the US is a constitutional republic; republic describes the type of state that it is (as opposed to a monarchy); it's constitutional because it's based on and confined to a constitution. With a constitution, a republic is like a mission with a plan & without a constitution, it's like a mission without a plan.
Democracy refers to the type of government system; the reason it's different from being a description of a state per se is because governments are "maintained" like a vehicle or "updated" like computer software; they have to go through periodic or ad hoc changes, such as elections or laws that are passed or repealed.
In reality, states can change (I think this boils down to where its geographic borders are, which can move around), but in principle, they can be perpetual (i.e., borders always stay the same).
The US Constitution, including the amendments, doesn't specifically grant voting rights to individuals*; being a democracy entails specifically being granted voting rights. Because of this, it is not accurate to refer to the US as a "constitutional democratic republic".
However, the US is a democracy in the sense that the states do grant voting rights to individuals, which the states and the people have the right to do because of the 10th Amendment:
The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.
Theoretically, the US could exist without individual voting rights (in practice today, it doesn't), and if this hypothetical US without individual voting rights were to exist, then it would literally be incorrect to describe the US as a "constitutional democratic republic" - it would be false in that scenario.
* What the US Constitution and amendments do say about individual voting rights (as opposed to votes by members of congress) are conditional stipulations to the states; they can sort of be paraphrased like this: you - the state - don't have to give your people the right to vote, but if you do, then you can't limit this right based on this or that characteristic or condition (race, sex, paying a poll tax, etc.).