Operating instructions

Controller Board 5-3
Figure 5-2 illustrates the DC distribution to various ICs and devices in the radio. The power
management architecture is centered on the MAKO IC (U3000). A battery supply is routed via a 3A
fuse (F9000) which goes directly to the electronic ON/OFF control (PMOS power FET Q3003) as
RAWB+. When the radio is turned ON, MECH_SW (ON/OFF/volume control) will trigger the MAKO
FET_ENX to low thus turning ON the PMOSFET device, and SWB+ is then distributed as shown in
Figure 5-2. SWB+ will continue to support the whole board until the radio is turned OFF.
2.1.1 Voltage Regulation
• Switcher U3020
Switcher (U3020) in conjunction with the MAKO power management IC (U3000) is a highly efficient
dc-dc buck converter. External components L3020 and C3202 are needed to filter out the dc-dc
converter output. In this application, it is configured as a Pulse Skipping Mode (PSM) with maximum
output current of 600mA. It generates an accurate 3.6V output, which supplies directly to the MAKO
internal VSW2 switcher circuit as well as other MAKO internal LDOs.
• Switcher U3021
Switcher (U3021) is a highly efficient dc-dc buck converter and same as switcher U3020. It is used
solely for OMAP processor core.
• Low Drop Out (LDO) Regulator U3008
LDO regulator (U3008) is an adjustable output voltage regulator which can supply 200mA load
current. It has an excellent Ripple Rejection Ratio and Short Circuit Protection. In this application,
LDO U3008 output is 2.3V which is set by the resistor divider R3028 and R3029. It supplies directly to
MAKO internal LDOs.
• Low Drop Out (LDO) Regulator U3002
LDO regulator (U3002) is an adjustable output voltage regulator which can supply 1A load current. In
this application, LDO U3002 generates an accurate 5.6V output which is set by the resistor divider
R3017 and R3018. It supplies directly to both VBUS1 and VBUS2 supplies. Q3005 and Q3006
prevent internal voltage leakage onto VBUS_SUPPLY (U3002 pin 5).
• MAKO LDO VBUS1
VBUS1 is a voltage regulation module that can be used to provide 5V with either 50mA or 500mA
load current suited for accessory and USB supply. Q3001 and Q3002 are used to control the low
current limit (50mA) or high current limit (500mA) of Vbus1.
When USB_CONNECT is toggled LOW, the PMOSFET (Q3001) is disabled and this will limit the max
load supply to 50mA. If a high current limit is desired, i.e. USB HOST mode, USB_CONNECT is
toggled HIGH turning ON the PMOSFET (Q3001) through Q3002 inverter, and this will limit the max
load supply to 500mA.
• MAKO LDO VBUS2
VBUS2 is a voltage regulation module that can be used to provide 5V and with only 500mA load
current. This supply is used for PA Pre-driver.
• MAKO LDOs
The MAKO power management IC (U3000) provides eight more LDOs. Some LDOs are
programmable to meet the requirement of various ASIC devices. V2, V3, and V9 are programmable
via SPI while V4, V5, V6, V8, and V10 are fixed. See Figure 5-2 for details.