Smith was also fined $50,000 by the league for what it called a flagrant violation of player safety rules. In a statement, the NFL said Boldin was in a defenseless position at the time contact was made.
Boldin was resting at home Monday, a day after being carted off the field following the scary collision in the Cardinals' 56-35 loss to the Jets at the Meadowlands. Smith briefly lost consciousness after the play, and still felt "a little fuzzy."
"Everybody was kind of telling me about it when we were in the locker room," Smith said before the suspension was handed down. "But to see something like that and see him have to get carted off the field, you never want to see something like that."
Team spokesman Mark Dalton said Boldin was fully mobile and was "resting comfortably at home" on Monday evening. The team released no other information on Boldin's condition.
Boldin's father, Carl Boldin, said his son suffered a fractured sinus membrane and took stitches to his lip as a result of the hit, according to the Palm Beach Post.
"They did a CT scan that came up negative and he was feeling good, so there was no reason to keep him," Carl Boldin said, according to the report.
"If it was left up to Anquan he would be able to play today," his father said, according to the newspaper. "But we have to err on the side of caution. If he's cleared medically, though, he'll play."
The suspension will sideline Smith for the Jets' game against Cincinnati on Oct. 12. New York has a bye this weekend. Earlier in the day, Smith said he would wait to hear from the league before deciding whether to appeal any suspension or fine.
"We respect and support the league's emphasis on player safety," Jets spokesman Bruce Speight said. "Knowing Eric, we are confident that he did not intend to injure Anquan Boldin. Anquan was hit from behind by another player that accelerated the collision with Eric. Our thoughts are with Anquan and we hope that he has a healthy recovery."
With 27 seconds left, Boldin tried to catch a pass from Kurt Warner in the end zone, but was hit in the back by Kerry Rhodes and then took a shot to his helmet from Smith. After being worked on for several minutes, Boldin was immobilized and placed on a stretcher before he was carted off the field.
Smith, who said he would try to get in touch with Boldin, insisted there was no malicious intent on his part.
"They just look at the end result, rather than everything that goes into the play," Smith said of those who think it was a dirty hit. "I'm coming to break up a pass and if I don't, it's going to be a touchdown. So, I'm going 100 percent and so is Kerry from the backside. Sometimes, somebody gets hit, angles change and things like that happen. It's not like I was directly leading with the top of my head from what I saw on the film."
The NFL's executive V.P. of football operations, Ray Anderson, was clear in his explanation of the league's judgments.
"The message is clear: There are no free passes for illegal technique when someone puts a player at risk, including the [offending player] himself," Anderson told ESPN senior NFL analyst Chris Mortensen. "Once you leave your feet to launch, in the view of the competition committee, you now have strict liability if you end up helmet to helmet with another player. When you launch, you take away your ability to be in control.
"This commissioner just sent a reminder to be read by all teams and the players received a copy of the memo about player safety. We said then, going forward, this is very, very serious stuff. We've had an emphasis here for a couple of years now and the commissioner is very concerned about concussions and potentially catastrophic injuries and we need to avoid putting our players at risk like this. As the memo said, the game is tough enough. we want to make sure players know how we want the game played."
Smith, who wasn't sure if he has a concussion, needed to see a replay after the game to figure out what happened.
"When I was going in, I was going to break up the ball," he said.
Arizona coach Ken Whisenhunt said he believed the hit violated the safety edict issued by commissioner Roger Goodell, but stopped short of calling for Smith to be suspended.
"I think it's one of the hits that falls into the category of being dangerous to players," Whisenhunt said. "Certainly, I'm sure that the league is going to look at this and will address it."
In a Sept. 17 letter to players, the league office stressed it would monitor "illegal and dangerous hits" in an effort to protect players in a violent sport.
"You never coach to go head-to-head," Jets coach Eric Mangini said. "That's something you never coach. Sometimes that stuff happens. You don't want to see it."
Information from ESPN senior NFL analyst Chris Mortensen and The Associated Press was used in this report.