BCM4330 Preliminary Data Sheet
Reset Circuits
Reset Circuits
The BCM4330 has three signals (Table 1) 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 23: “Power-Up Sequence and Timing,” on page 158.
Table 1: 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 BCM4330 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.
Logic High Level: 1.08V–3.6V. 200k pull-down resistor included.
BT_REG_ON
This signal is used by the PMU (with WL_REG_ON) to decide whether or not to power down
the internal BCM4330 regulators. If BT_REG_ON and WL_REG_ON are low, the regulators will
be disabled.
Logic High Level: 1.08V–3.6V. 200k pull-down resistor included.
BT_RST_N
Low asserting reset for the Bluetooth core. This pin has no effect on WLAN and does not
control any PMU functions. It must be driven high or low (not left floating).
In addition, two other input signals control PMU modes:
• When EXT_SMPS_REQ is pulled high, it forces CBUCK to stay on, even when the other regulators are shut
down by WL_REG_ON or BT_REG_ON.
• When WLAN and/or Bluetooth are out of reset and EXT_SMPS_REQ is high, then pulling EXT_PWM_REQ
high makes CBUCK go into PWM mode, even if internal settings from WLAN and/or Bluetooth are
requesting burst mode. During such contention, the request for the higher-power mode wins.
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BROADCOM
BCM4330 Preliminary Data Sheet
April 28, 2011 • 4330-DS304-RI
Page 31
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