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Patent And Technology Partner To The World's Most Successful Companies

Patent And Technology Partner To The World's Most Successful Companies


The Broadcom BCM4334 – Circuit Innovation Snapshot

The Broadcom BCM4334 is a single chip dual-band combo device supporting 802.11n,
Bluetooth 4.0+HS, and FM receiver and started showing up in smartphones in mid 2012; it marked Broadcom’s transition from 65-nm to 40-nm processing in this space. Chipworks has documented wins for the device in the Samsung Galaxy S3, Apple iPhone 5, Blackberry Q10, and HTC One VX. The combined phones from these companies hold over 90% market share in 2013 in the premium smartphone category.

Considering only Q4 2012 annualized sales volumes for the iPhone and Galaxy S3, Broadcom could be realizing $400+ million in annual revenue (assuming a manufacturing cost of $1.75 per device and a reasonable mark-up) from these two devices alone. Considering that similar results were cataloged for the prior generation BCM4330 and the BCM4329, we know that Broadcom has a market winner on its hands in premium phones,  lower cost smart phones, and in other wifi-enabled devices. These chips are everywhere.

Broadcom BCM4334 shown inside a Murata module

Broadcom BCM4334 shown inside a Murata module. We have written in some detail on the module in the past.

Volume helps drive price competitiveness, but in the premium category performance and features matter too. Broadcom is a perennial leader in R&D for this space and has a well deserved place in the market. The full analog Circuit Analysis Report that we have completed on this device shows a lot of innovation. The novel ultra-low power circuit designs and interesting radio receiver architecture are among those design features that stood out as innovative design approaches when compared to other devices that we have looked at.

Below we are showing a portion of the simplified functional block diagram of the Bluetooth receiver on the device. Two independent LNA and down-converting mixer channels are used:

  • The first LNA processes the single-ended input RF signal BT_ANT from the Bluetooth antenna (after an optional external LNA)
  • The second LNA receives a pair of differential signals from the Wi-Fi antenna after a Wi-Fi/BT shared LNA likely for Bluetooth v4.0 +HS.

The amplified RF signals are then fed to two in-phase and quadrature mixers. A shared Inphase/Quadrature polyphase band-pass filtering IF is followed to remove the RF components and a resistor network circuit combines the I/Q signals so a single 2nd order sigma delta ADC can process the received signal.

Figure 1 Simplified Bluetooth Receiver Functional Block Diagram

Simplified Bluetooth Receiver Functional Block Diagram (screen shot from Chipworks ICWorks Browser)

All the detailed analog circuit analysis can be found in the Chipworks circuit analysis report of the Broadcom BCM4334 including circuit analysis of the Bluetooth transceiver block, FM receiver block, the power management block and the Wi-Fi transceiver blocks. Visit the Chipworks Report Store for details.