Mobile Phone IC For 77656-11 Original
The SKY77656-11 (often referred to simply as the 77656-11) is a high-performance Multimode Multiband (MMMB) Power Amplifier Module (PAM) manufactured by Skyworks Solutions.
It is a critical component in the radio frequency (RF) front-end of mobile devices, primarily responsible for boosting cellular signals to the power levels required for transmission to cell towers. It is a staple in many Samsung Galaxy flagship and mid-range devices, including the S9, Note 8, and J6.
Technical Specifications: SKY77656-11
| Feature | Specification Detail |
| Model Number | SKY77656-11 / 77656-11 |
| Manufacturer | Skyworks Solutions, Inc. |
| Component Type | Multimode Multiband Power Amplifier Module (PAM) |
| Package Type | MCM (Multi-Chip Module), 40-pad |
| Package Dimensions | 4.3 mm x 6.95 mm x 0.75 mm |
| Network Support | Quad-band GSM/EDGE, WCDMA, HSDPA, HSUPA, LTE |
| LTE Band Support | Bands 1–5, 8, 12, 13, 17, 20, 26, 28, 34, 39 |
| Control Interface | Two-wire MIPI® RFFE (SCLK, SDATA) |
| Input/Output Impedance | 50 $\Omega$ (Internally matched) |
| Technology | InGaP/GaAs HBT (Heterojunction Bipolar Transistor) |
| Operating Voltage ($V_{CC}$) | 3.2V to 4.2V (Direct battery or Buck DC/DC connection) |
Core Functional Roles
The 77656-11 is designed to handle the complex requirements of modern global roaming handsets.
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Hybrid Architecture: It features separate paths for GSM and 3G/4G signals. This separation allows the IC to optimize efficiency for legacy voice calls while maintaining the high linearity required for high-speed LTE data.
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MIPI RFFE Control: The module is fully programmable via the MIPI interface. This allows the phone’s modem to dynamically adjust power levels and switch between bands in milliseconds.
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Average Power Tracking (APT): It is optimized for use with APT systems, which adjust the supply voltage based on the actual power needed for transmission, significantly extending battery life.
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Carrier Aggregation (CA): The IC supports LTE Downlink Carrier Aggregation with low harmonic levels, ensuring that multi-band data transmission does not interfere with other internal radio components.
Compatibility & Applications
This IC is most commonly found in Samsung’s global and regional variants from the 2017–2019 era.
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Samsung Galaxy S9 / S9+ (G960F, G965F)
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Samsung Galaxy Note 8 (N950F)
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Samsung Galaxy A30 / A50 (Select variants)
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Samsung Galaxy J6 (J600)
Common Symptoms of Failure
Because the 77656-11 sits at the very end of the transmit path, it is highly susceptible to damage from antenna-related issues or electrical stress.
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“No Service” Error: The phone shows an IMEI and Baseband version, but the signal bars remain empty or show a “blocked” circle icon.
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Weak Signal / Signal Dropping: The device might show a signal near a cell tower but lose it entirely indoors or when moving.
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Radio Power Off: In the hidden testing menu ($*\#*\#4636\#*\#*$), the “Mobile Radio Power” toggle may be stuck in the “Off” position.
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High Battery Drain during Calls: A partially damaged PA might draw excessive current to maintain a connection, causing the phone to heat up significantly during voice or data use.
Professional Repair and Installation Notes
The SKY77656-11 is a 40-pad MCM component. Due to its size and the density of the motherboard pads, it requires advanced micro-soldering.
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Heat Profile: Use a hot air station at $330\degree\text{C}$ to $345\degree\text{C}$. Excessive heat can cause the internal layers of the laminate substrate to delaminate.
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Orientation: Pay close attention to the Pin 1 marker (usually a small laser-etched dot). Installing the chip backwards will likely cause a short circuit on the battery line ($V_{BAT}$).
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Underfill: Note that many Samsung boards use a hard underfill epoxy. This must be carefully softened and cleared from the edges at $200\degree\text{C}$ before attempting to lift the IC.
