February 14, 2012 6816985H01-F
4.5-10 900 MHz Detailed Theories of Operation: VOCON Functional Blocks
4.5.6.2 Audio and Power Section
Two main ICs reside in the audio and power section of the schematic diagram:
• the MAKO IC (U701)
• the VSW1 Driver IC (Q702)
4.5.6.2.1 MAKO IC (U701)
The MAKO IC is a mixed-signal IC that provides control, clock generation, digital support, audio, and
voltage regulation functionality. It comes in a 176-pin, ball-grid array (BGA) package with 0.8mm
pitch solder balls. The MAKO IC is supplied with switched battery voltage SW_B+.
4.5.6.2.1.1 Voltage Regulation
The MAKO IC contains all of the regulators that are used in the design of the VOCON board:
VSW1, VSW2, V_2.9, V1.55, V1.875, and VCC5. VSW1 is a programmable switching regulator
controlled by the MAKO IC on pin SW1_SUMCOMP_DL, while the current is sourced by a driver
Q300 using the switched battery voltage (SW_B+). The switching frequency of VSW1 (R711) is
programmable by the dual-core processor through the SPI bus. The VSW1 voltage is supplied to the
input pin of MAKO's VSW2 regulator (pin SW2_VCCS).
The VSW2 regulator is a SPI programmable switching regulator. The initial and programmed output
of VSW2 (C715) is 2.3 volts. The VSW2 voltage is used internal to the MAKO IC to supply the 1.875
volt (V1.875) and 1.55 volt (V1.55) linear voltage regulators. The V1.875 voltage (L703) is supplied
to the dual-core processor U800 (EIM voltage), SRAM U804, and Flash memory U803. The V1.55
voltage (R718) is supplied to the dual-core processor U800 (core voltage).
The V_2.9 volt regulator is a linear regulator within the MAKO IC that used VSW1 as its input. The
initial output of V_2.9 (L704) is 2.775 volts, which is then programmed to 2.9 volts by the dual-core
processor via the SPI bus. The V_2.9 voltage is supplied to the dual-core processor (I/O ring - SPI,
BBP, SAP, UART, GPIO, etc.), the display module connector J601, and the many discrete
components that interface with the dual-core processor and the MAKO IC.
4.5.6.2.1.2 Microcontroller Unit (MCU) Interface
The MAKO IC has a four-wire, SPI connection to the dual-core processor (SPI B). The SPI B clock is
connected to the SPI_CLK pin E6. The SPI B MOSI line is connected to the SPI_DI pin B6. The SPI
B MISO line is connected to the SPI_DO pin C6. The MAKO SPI B chip-select signal is connected to
the SPI_CS pin D6. Through this interface, the dual-core processor can program the voltage
regulators, the CODEC, the transmit and receive audio filters and amplifiers, digital support
mulitplexing, and read information from the ADC.
The MAKO IC has a 10-bit ADC with eight general-purpose channels and two voltage-monitoring
channels. Five out of the eight general-purpose channels are assigned to the display backlight
button on the control head (ATOD_2), the monitor volume (ATOD_1), the two-position toggle switch
(ATOD_3), the OPT_SEL_IN (ATOD_8), and board type ID (ATOD_5). The other three general
purpose channels are unused. Battery voltage is also monitored by the ADC. The dual-core
processor reads the ADC values through the SPI bus.
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