What Chips Are Inside a Smartphone? The Main Chips Explained
A smartphone does not hold just one chip. It holds many semiconductor chips, each with a different job. At the center is the SoC, which does the computing. Around it sit memory and storage, chips that handle radio waves, a chip that manages power, sensors and more. Each job suits a different material or way of making chips, so separate chips share the work.
What you'll learn
- Which chips are inside a phone, and what each one does
- Which circuits sit inside the SoC, the center of the computing (CPU, GPU, NPU and more)
- Why a phone needs so many radio parts, and why it needs so many filters
- A real phone as an example, and why you can't compare phones by "core count" or "nm" alone
Prerequisites: none. The SoC part is easier to follow if you have read "What Is a CPU?" and "What Is an Integrated Circuit?"
Where you see it: your phone's jobs through the day
In the morning, you read messages. At the station, you may tap your phone on the ticket gate. At lunch, you take photos and walk with a map open. At night, you plug in the charger. In each of these moments, a different semiconductor chip is at work.
For example, the screen turns when you turn the phone on its side. That works thanks to a sensor chip that feels the tilt. In this article, we take a tour inside one phone and meet the main chips in turn.
A "map" of the inside of a phone
Inside a phone is a board that holds the parts and links them with thin wires. This is called the circuit board. Most of the black, square chips sit side by side on this board. The screen, cameras and battery are separate parts, linked to the board by thin cables.
The figure below is a simple sketch of the main chips, grouped by job. The real layout, size and number of chips are very different from one model to the next.
The center of the computing: what is inside the SoC?
At the center of the board is a large chip that does the computing. Inside it, many kinds of circuits are built into one chip, not just a CPU. A chip that gathers a device's main functions into one like this is called an SoC (system on a chip). How a chip itself works is explained in "What Is an Integrated Circuit?"
The main circuits inside an SoC are these:
- CPU: the part that carries out an app's instructions one by one ("What Is a CPU?"). One full set of circuits that carries out instructions is called a "core."
- GPU: the circuit that draws the pictures shown on the screen. It is good at running many copies of the same calculation at once.
- NPU: a circuit built for AI math. It handles tasks such as recognizing things in a photo, using little power.
- ISP (image signal processor): the circuit that turns the rows of numbers sent by the camera sensor into a finished photo.
- Modem: the part that converts between the signal sent over cell radio waves and data made of 0s and 1s (explained later).
What goes into the SoC differs by maker and model. For example, Qualcomm's SoC "Snapdragon 8 Gen 3" (announced in 2023) has the modem inside. On the other hand, teardowns of the iPhone 16 Pro (released in 2024) show its modem is a separate chip made by Qualcomm.
The SoC in the iPhone 16 Pro is the "A18 Pro." Apple's specs give it a 6-core CPU: 2 high-performance cores and 4 high-efficiency cores. Apple says it is made with "second-generation 3-nanometer" technology.
Memory and storage: a place to work and a place to keep
A phone also has memory, which holds the data in use, and storage, which keeps photos and apps. The difference is explained in "Memory vs Storage: What's the Difference?" Here we look at what is special about phones.
A phone's working memory is DRAM designed to use less power. This standard is called LPDDR, and "LP" stands for "Low Power." A teardown of the iPhone 16 Pro found 8 GB of it, made by Micron.
In the iPhone 16 Pro, this memory is stacked right on top of the SoC. The closer two chips are, the faster they can trade data, and the less power it takes. Stacking also saves space on the board.
Storage uses flash memory chips, which keep data even with the power off. A common standard for phones is "UFS," set by the industry group JEDEC.
Chips that handle radio waves: from the modem to the antenna
Calls and mobile data travel by radio waves to and from a base station. A base station is the antenna equipment that a mobile carrier puts on rooftops and towers. Inside the phone, data passes through several chips before it becomes radio waves.
The first stage is a circuit that turns 0s and 1s into a signal that can ride on radio waves. When receiving, it does the reverse and pulls the data out of the signal. This circuit is called the modem, or the baseband. The idea of turning data into the shape of a wave is also explained in "How Does Wi-Fi Work?"
The next stage moves the signal up to the pitch of the radio wave that is actually sent. A wave's pitch is how many times it vibrates in one second, which is called its frequency. A phone's radio waves mostly vibrate hundreds of millions to billions of times per second. The circuit that shifts the frequency is called the transceiver.
Just before the antenna, parts that handle radio waves directly are packed together. There is an amplifier that strengthens the waves being sent, filters that remove unwanted frequencies, and switches that pick which path to use. Together, these are called the "RF front end." RF stands for radio frequency, the range of frequencies used for wireless.
The amplifier that strengthens outgoing waves is often a chip made not of silicon but of a material called gallium arsenide. This material makes it easier to put out high power efficiently at high frequencies (according to a paper abstract from IMS 2026, an international conference). On the receiving side, a different amplifier boosts very weak waves while adding as little noise as possible.
Why a phone needs so many filters
The frequency ranges used by cell phones are set by country, by carrier, and by generation, such as 4G and 5G. Each of these ranges is called a "band." To work abroad too, one phone supports many bands. The iPhone 16 Pro spec sheet lists dozens of 4G and 5G bands.
A filter is a part that lets through only a set range of frequencies and blocks the rest. A different band needs a different filter. Some bands use one frequency for sending and another for receiving. These also need a pair of filters that separates the two at the same time. A 2017 paper (Mahon) says that advanced phones of that time held more than 60 filters.
Most phone filters first turn the electrical signal into a very small vibration, then sort it. They use a material that stretches and shrinks very slightly when a voltage is applied. This property is called "piezoelectric." The part is shaped so that only vibrations at set frequencies travel well, so other frequencies have a hard time getting through.
When the vibration travels along the surface of the material, the part is called a SAW (surface acoustic wave) filter. As a rough guide, it is used up to about 2 GHz (2 billion vibrations per second).
The other type makes a thin film vibrate through its thickness. It is called a BAW (bulk acoustic wave) filter. This type suits higher frequencies. Sources differ on where one type gives way to the other, at about 1.5 to 2.5 GHz.
Wi-Fi, Bluetooth and location
Home Wi-Fi and Bluetooth for wireless earbuds use other frequencies and methods than cell phone networks. They are often handled by a chip separate from the modem. "Wi-Fi vs Bluetooth vs LPWA" compares them in a table. A map app can show where you are because a circuit receives radio waves from GPS and other satellites.
Chips that manage power: the PMIC and charging
The circuits inside the SoC run on about 1 volt or less. The battery's voltage is higher, and it changes as the battery runs down. The other chips each need their own voltage, too. And even when the CPU suddenly gets busy, the voltage must not swing much.
The chip that makes these different voltages from the battery is the PMIC (power management IC). It packs many voltage-changing circuits into one chip. It also controls which circuit gets power, and when. The main way it changes voltage is to switch the current on and off very fast, which sets the average voltage. This is the same idea explained in "What Is a Power Semiconductor?", scaled down for small amounts of power.
There is also a chip that manages charging the battery. According to Texas Instruments, a lithium-ion battery is first charged at a set current. As it nears full, the charger holds the voltage steady and lets the current taper off.
Chips for the screen, cameras and sound
A screen redraws the brightness of many tiny dots, or pixels, at short intervals. The iPhone 16 Pro's screen has about 3.16 million pixels. Apple's specs say it redraws them up to 120 times per second. The chip that sends the signals for which pixels to light, and how brightly, is the display driver IC.
When your finger touches the screen, the way charge builds up between thin electrodes spread across the screen changes slightly. A chip called the touch controller works out where your finger is from that change.
In the camera, an image sensor turns light into electricity and makes a number for each pixel ("How Do Image Sensors Work?"). The ISP inside the SoC turns those numbers into a photo, working out colors and reducing graininess.
For sound, one circuit turns the electrical wave of sound picked up by the microphone into 0s and 1s. It also turns music stored as numbers back into an electrical wave. This circuit is called the audio codec. To drive the speaker, an amp (amplifier) then strengthens the electrical wave.
Sensors that feel motion: MEMS
Screen rotation, step counting and shake correction for photos all use sensors that measure the phone's tilt and motion. Inside them are tiny "moving parts," carved out with chipmaking technology. A part that builds in mechanical parts as well as electrical circuits like this is called MEMS.
An accelerometer holds a tiny weight held up by springs. When the phone moves, the weight tends to stay where it was, so it shifts slightly. The shift changes the gap to an electrode right next to it, which changes how charge builds up. Measuring this tells the sensor how the phone moved (according to Analog Devices). Gravity also pulls on the weight, so even at rest the sensor knows which way is down.
A gyroscope is a sensor that measures how fast the phone turns. It keeps a weight vibrating, and measures the sideways push on it when the phone turns.
Tap to pay: NFC and the secure element
You can tap your phone to pay at a ticket gate or in a store. That works because of an NFC chip, which talks over a few centimeters. According to the NFC Forum, NFC uses a frequency of 13.56 MHz. In Japan, FeliCa, a system used in transit cards, uses the same frequency.
Important data, such as card numbers, is kept in a well-guarded chip, apart from where ordinary apps run. This chip is called the secure element. According to Apple, Apple Pay card data is encrypted and stored in the secure element. A store's card reader talks directly with the secure element through the NFC chip.
A real phone: the iPhone 16 Pro (2024)
The table below is based on teardowns by iFixit, a repair website, and TechInsights, a research firm. It is not a parts list published by Apple.
| Job | Chip found in teardowns (maker) |
|---|---|
| Center of the computing (SoC) | A18 Pro (Apple) |
| Memory | LPDDR, 8 GB (Micron). Stacked on the SoC |
| Storage | Flash memory (Kioxia) |
| Modem | SDX71M (Qualcomm) |
| Radio parts | Modules that combine amplifiers and other parts (Skyworks, Qorvo and others) |
| Audio amp | Cirrus Logic |
| NFC and secure element | NXP |
The chips in the table are the ones found in the units that were taken apart. Even the same model may use parts from other companies, depending on when it was made. Some of the identifications are estimates. Sources also describe some points differently, such as the memory generation.
Why not put everything on one chip?
You cannot build everything in a phone on one chip. The amplifier that strengthens radio waves uses gallium arsenide, and the filters use piezoelectric materials. These are different materials from silicon. Motion sensors also need special steps to make their moving parts.
Common misconceptions
Myth: A phone holds just one "phone chip"
In fact, besides the SoC, it holds many chips: memory, a modem, radio parts, power management, sensors and more. Ads and news often mention only the SoC's name, such as "A18 Pro" or "Snapdragon." That is why it can look like there is only one.
Myth: The more CPU cores a phone has, the faster it is
In fact, speed depends on the type of cores and how they are used. The A18 Pro's CPU has 6 cores, but 4 of them are high-efficiency cores for doing light work on little power. Also, an app cannot always use many cores at once. And a phone has no fan, so it may slow down when it gets hot. Core count is easy to compare on a spec sheet, so people tend to judge by it alone.
Myth: The "X nm" of the SoC tells you how well a phone performs
In fact, a number such as "3nm" is the name of a manufacturing generation. The same number can mean different things at different companies ("What Does 2nm or 3nm Mean?"). Performance also depends a lot on the circuit design and how heat is carried away. Signal quality and battery life also depend on chips other than the SoC.
By the numbers
| Number | What it counts |
|---|---|
| About 19 billion | Transistors in the A17 Pro (for the 2023 iPhone 15 Pro), as announced by Apple. The number for the A18 Pro has not been published |
| 8 GB | Memory in the iPhone 16 Pro, from teardowns (Apple does not publish it) |
| More than 60 | Filters in an advanced phone around 2017 (Mahon's paper) |
If you counted 19 billion transistors at one per second, it would take about 600 years. But like core count, the number of transistors does not tell you the performance on its own.
Learn more
- See the differences in a table: CPU vs GPU vs NPU, DDR vs LPDDR vs GDDR vs HBM, ASIC vs FPGA vs SoC, LDO vs switching regulator, Capacitive vs piezoresistive MEMS
- Terms for the next step: DVFS (changing voltage and speed to match the workload), DC-DC converters, HBTs (the transistors in radio amplifiers)
- Try the numbers: the dBm converter (units for signal strength), the DC-DC converter calculator
- Related articles: "Why Are GPUs Used for AI?", "What Is a Semiconductor Foundry?"