ADVANCE
CYW4356
2. Power Supplies and Power Management
2.1 Power Supply Topology
One Buck regulator, multiple LDO regulators, and a power management unit (PMU) are integrated into the CYW4356. All regulators
are programmable via the PMU. These blocks simplify power supply design for Bluetooth, WLAN, and FM functions in embedded
designs.
A single VBAT (3.0V to 5.25V DC max.) and VIO supply (1.8V to 3.3V) can be used, with all additional voltages being provided by the
regulators in the CYW4356.
Two control signals, BT_REG_ON and WL_REG_ON, are used to power-up the regulators and take the respective section out of
reset. The CBUCK CLDO and LNLDO power up when any of the reset signals are deasserted. All regulators are powered down only
when both BT_REG_ON and WL_REG_ON are deasserted. The CLDO and LNLDO may be turned off/on based on the dynamic
demands of the digital baseband.
The CYW4356 allows for an extremely low power-consumption mode by completely shutting down the CBUCK, CLDO, and LNLDO
regulators. When in this state, LPLDO1 (which is a low-power linear regulator supplied by the system VIO supply) provides the
CYW4356 with all the voltages it requires, further reducing leakage currents.
2.2 CYW4356 PMU Features
■ VBAT to 1.35Vout (600 mA maximum) Core-Buck (CBUCK) switching regulator
■ VBAT to 3.3Vout (600 mA maximum) LDO3P3
■ VBAT to 3.3Vout (150 mA maximum) LDO3P3_B
■ VBAT to 2.5V out (70 mA maximum) BTLDO2P5
■ 1.35V to 1.2Vout (150 mA maximum) LNLDO
■ 1.35V to 1.2Vout (300 mA maximum) CLDO with bypass mode for deep-sleep
■ Additional internal LDOs (not externally accessible)
Figure 3 illustrates the typical power topology for the CYW4356. The shaded areas are internal to the CYW4356.
Document Number: 002-15053 Rev. *D
Page 10 of 155
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