It has been another busy week for Australia's top brokers. This has led to the release of a number of broker notes.

Three broker buy ratings that you might want to know more about are summarised below. Here's why brokers think these ASX shares are in the buy zone:

According to a note out of Goldman Sachs, its analysts have retained their buy rating on this mining giant's shares with a trimmed price target of $49.00. This follows the release of a quarterly update that was slightly stronger than the broker was expecting. Goldman was pleased with BHP's iron ore and copper production, noting that both were ahead of its estimates for the period. However, taking some of the shine off the quarterly performance was its metallurgical coal operations, which reported production 17% lower than Goldman was expecting. This was due partly to wet weather. Nevertheless, the broker remains positive and thinks its shares are good value at 0.9x net asset value. The BHP share price is trading at $44.64 on Friday.

A note out of Bell Potter reveals that its analysts have resumed coverage on this retail conglomerate's shares with a buy rating and $35.00 price target. The broker believes that Premier Investments' shares are good value at 14x estimated FY 2026 earnings. In fact, the broker feels this valuation is conservative given the value it sees emerging from the potential demerger of its two key brands, Smiggle and Peter Alexander. The broker highlights that these brands are worthy of a global roll-out and are highly profitable. Bell Potter also expects 4%+ dividend yields through to at least FY 2026. The Premier Investments share price is fetching $29.04 this afternoon.

Analysts at Morgan Stanley have retained their overweight rating and $31.80 price target on this sleep disorder treatment company's shares. This follows news that pharmaceutical giant Eli Lily & Co (NYSE: LLY) has reported positive phase three top-line data for its sleep apnoea-focused weight loss drug trial. Morgan Stanley notes that the trial delivered strong results and reduced the apnoea-hypopnea index (HPI) materially. However, it believes this is actually good news for ResMed as it grows the awareness of sleep apnoea. It is also worth noting that the strongest results from the trial came from the combination of the drug and a sleep treatment device. The ResMed share price is trading at $27.79 on Friday.