BCM89359 Advance Data Sheet
Power-Off Shutdown
Power-Off Shutdown
The BCM89359 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 BCM89359 is not needed in the system,
VDDIO_RF and VDDC are shut down while VDDIO remains powered. This allows the BCM89359 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 BCM89359, 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 BCM89359 to be fully integrated in an embedded device and take full advantage of the lowest
power-savings modes.
When the BCM89359 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 BCM89359 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 19: “Power-Up Sequence and Timing,” on page 142.
Table 2: Power-Up/Power-Down/Reset Control Signals
Signal
Description
WL_REG_ON
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 BCM89359 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 kΩ pull-down
resistor that is enabled by default. It can be disabled through programming.
BT_REG_ON
This signal is used by the PMU (with WL_REG_ON) to decide whether or not to power
down the internal BCM89359 regulators. If BT_REG_ON and WL_REG_ON are low, the
regulators will be disabled. This pin has an internal 200 kΩ pull-down resistor that is
enabled by default. It can be disabled through programming.
Broadcom®
September 9, 2014 • 89359-DS100-R
Page 22
BROADCOM CONFIDENTIAL
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