BCM4356XKUBGT Datasheet, PDF (25/195 Pages) Cypress Semiconductor – Single-Chip 5G WiFi IEEE 802.11ac 2×2 MAC/ Baseband/Radio with Integrated Bluetooth 4.1, FM Receiver, and Wireless Charging

BCM4356 Advance Data Sheet
Power-Off Shutdown
Power-Off Shutdown
The BCM4356 provides a low-power shutdown feature that allows the device to be turned off while the host, and
any other devices in the system, remain operational. When the BCM4356 is not needed in the system,
VDDIO_RF and VDDC are shut down while VBAT and VDDIO remain powered. This allows the BCM4356 to be
effectively off while keeping the I/O pins powered so that they do not draw extra current from any other devices
connected to the I/O.
During a low-power shut-down state, provided VDDIO remains applied to the BCM4356, all outputs are tristated,
and most inputs signals are disabled. Input voltages must remain within the limits defined for normal operation.
This is done to prevent current paths or create loading on any digital signals in the system, and enables the
BCM4356 to be fully integrated in an embedded device and take full advantage of the lowest power-savings
modes.
When the BCM4356 is powered on from this state, it is the same as a normal power-up and the device does not
retain any information about its state from before it was powered down.
Power-Up/Power-Down/Reset Circuits
The BCM4356 has two signals (see Table 2) that enable or disable the Bluetooth and WLAN circuits and the
internal regulator blocks, allowing the host to control power consumption. For timing diagrams of these signals
and the required power-up sequences, see Section 21: “Power-Up Sequence and Timing,” on page 182.
Signal
WL_REG_ON
BT_REG_ON
Table 2: Power-Up/Power-Down/Reset Control Signals
Description
This signal is used by the PMU (with BT_REG_ON) to power up the WLAN section. It is also
OR-gated with the BT_REG_ON input to control the internal BCM4356 regulators. When this
pin is high, the regulators are enabled and the WLAN section is out of reset. When this pin is
low, the WLAN section is in reset. If BT_REG_ON and WL_REG_ON are both low, the
regulators are disabled. This pin has an internal 200 k pull-down resistor that is enabled by
default. It can be disabled through programming.
This signal is used by the PMU (with WL_REG_ON) to decide whether or not to power down
the internal BCM4356 regulators. If BT_REG_ON and WL_REG_ON are low, the regulators
will be disabled. This pin has an internal 200 k pull-down resistor that is enabled by default.
It can be disabled through programming.
Broadcom^®
May 8, 2015 • 4356-DS103-R
BROADCOM CONFIDENTIAL
Page 24