General Purpose LDO Cross Reference HP1117 Against AMS1117

AMS1117 is the default on a great many boards. For an input under 15V, a load under 1A and a 3.3V or 5V linear rail, you drop in a three-terminal LDO and most designers do not think about it again. Used long enough, that socket simply belongs to it.

Customers now ask whether they can move to HP1117 from Hypower, keep the same socket and the same external circuit, and lose nothing in the parameters. Answering that means putting the two parts side by side and going item by item. The list below compares published product parameters, and the finer electrical characteristics are discussed after the table.

First confirm it is the same socket

Both parts are three-terminal low dropout linear regulators with 1A output current, both come in fixed and adjustable versions, and both usually sit under a 5V or 12V bus providing a second-stage rail for an MCU, an interface or a sensor.

The pinout also matches: ground or adjust, output, input. That is the precondition for a drop-in at the AMS1117 socket and the first thing customers ask about. Very little has to change on the board; in most cases only the input and output capacitor values and the pad footprint need confirming.

On applications, HP1117 is positioned by Hypower for always-on products such as televisions, home appliances and set-top boxes, which is the same class of socket where AMS1117 has been used for years.

The cross reference list at a glance

Read down the table and neither part sweeps it; each has its own position. Only two items are worth stopping to calculate.

Two items that separate the parts

Input voltage first. HP1117 is rated to 18V input, while the absolute maximum input voltage in the AMS1117 datasheet is 15V. Those 3V are practical on a board fed from a 12V bus, where harness surges and load steps push upward, and the 18V rating leaves wider margin. The product still runs from the same 12V supply; the front end simply fluctuates more, and HP1117 tolerates it better.

Quiescent current next. HP1117 specifies 2mA typical, AMS1117 specifies 5mA typical. On always-on products the difference is visible: an appliance with standby, a set-top box or a TV main board is held up by the always-on rail while idle, so 3mA less drawn by the LDO itself accumulates over long standby periods into a real contribution to the product's standby power. In low-power designs quiescent current is usually counted before dropout, and HP1117 lands right on that point.

Two items that tie

Dropout is essentially identical. AMS1117 specifies 1.3V maximum at the full 1A load, and HP1117 specifies 1.3V at 1A, the same order. The minimum headroom requirement between input and output is therefore close, and for fixed transitions such as 5V to 3.3V or 6V to 5V, the thermal and input-floor calculations do not have to change.

Ripple rejection is also close. HP1117 reaches 70dB at 120Hz, while the AMS1117 family lands roughly between 60dB and 75dB under the same condition, with the exact figure varying by output voltage version. That order is enough for a second-stage rail feeding an MCU or an analog front end, so it is not a reason to choose between them.

One point to state plainly: the Hypower product page publishes a parameter summary. Line regulation, load regulation, current limit threshold and thermal shutdown are finer characteristics that should be compared against the complete datasheet obtained from the manufacturer. That comparison follows written manufacturer data; nothing here is inferred.

A smaller package option

On packages, HP1117 offers SOT223, SOT89-3L and TO252; AMS1117 offers SOT-223, TO-252 and SO-8.

The shared options are SOT-223 and TO-252, the two most common packages for a 1A LDO, and their pads align directly, so the part changes without the board changing. What HP1117 adds is SOT89-3L, a small outline that suits a board already full and looking to squeeze one more regulator into a corner. What AMS1117 adds is SO-8, seen mostly in multi-rail designs or where an extra thermal pad is wanted.

For a general board built around SOT-223, the two are level on package, and when a smaller footprint matters, the SOT89-3L version of HP1117 is the first thing to look at.

Three things to verify before the swap

With the parameters compared, three checks remain before touching the board.

The first is the input and output capacitors. LDO stability is sensitive to the ESR and value of these two capacitors, so recheck them against the recommended values in the HP1117 datasheet rather than copying the old bill of materials.

The second is the pad footprint. SOT-223 and TO-252 generally align, but the thermal pad dimensions should be confirmed against the new part's drawing, especially the copper area that carries the current.

The third is the actual temperature rise. Dropout and output current set how much power the LDO dissipates, and copper area and airflow differ from board to board, so the final rise has to be measured on a sample rather than calculated from the manual.

Boards that do not need to change

With those three checks done, whether to swap still depends on the board.

A board already using AMS1117 with an input below 15V, where standby power is not a design focus, has no compelling reason to change; staying on the original solution is the least work. For a new design, for a localization program, for squeezing standby power, or for wider input margin, the advantages of HP1117 are the ones that actually get used.

How to get samples and the full datasheet

HP1117 is a domestic part. Samples and datasheets come through the distributor channel, with more room on lead time and cost than imported devices, and projects needing long-term supply can reserve stock ahead. Its package and pinout line up with AMS1117, so the sensible path is to validate on the existing board first and then decide whether to move it into volume.

HP1117 samples and the complete datasheet are already on hand at Shenzhen Manduic Technology Co., Ltd., an authorized distributor of Hypower, and we can run the cross-reference and peripheral circuit review together with you.

For samples, product datasheets, detailed adaptation solutions or technical support, please contact us:

Tel: +86-150-1290-5940

Email: sales@manduic.com

Website: www.manduic.com