BCM89071A1CUBXGT Datasheet, PDF (17/69 Pages) Cypress Semiconductor – Single-Chip Automotive Grade Bluetooth Transceiver and Baseband Processor

BCM89071 Data Sheet
Internal LDO
Internal LDO
Two internal Low Drop-Out (LDO) voltage regulators eliminate the need for external voltage regulators and
therefore reduce the BOM. The first LDO is a preregulator (HV LDO). The second LDO (Main LDO) supplies the
main power to the BCM89071 (see Figure 2 on page 12).
The HV LDO has an input voltage range of 2.3V to 5.5V. The input VBAT is ideal for batteries. The VREGHV
output is programmable from 1.8V to 3.3V, in 100 mV steps. The dropout voltage is 200 mV. The HV LDO can
supply up to 95 mA, which leaves spare power for external circuitry such as an RF power amp for higher transmit
power. If the HV LDO is not used, to turn off the HV LDO and minimize current consumption, connect the VBAT
input to the VREGHV output. Firmware can then disable the HV LDO, saving the quiescent current.
The HV LDO default output voltage is 2.9V, allowing this regulator to be used to power external NV memory
devices, as well as the VDDO rail. The firmware can then adjust this output to as low as 1.8V, if desired, to power
VDDTF.
The main LDO has a 1.22V output (VREG) and is used to supply main power to the BCM89071 (see Figure 4).
The input of this LDO (VREGHV) has an input voltage range of from 1.63V to 3.63V. The output of the HV LDO
is internally connected to the input to the main LDO. Power can be applied to VREGHV when the HV LDO is
not used. The main LDO supplies power to the entire device for Class 2 operation. The main LDO can drive up
to 60 mA, which leaves spare power for external circuitry. The main LDO is bypassed by not connecting anything
to its output (VREG) and driving 1.12V–1.32V directly to VDDC and VDDRF.
REG_EN provides a control signal for the host to control power to the BCM89071. When power is enabled, the
BCM89071 will require complete initialization.
Figure 4: LDO Functional Block Diagram
BCM89071
HV LDO
Main LDO
REG_EN VBAT
VREGHV
VREG
Broadcom^®
April 16, 2015 • 89071-DS106-R
Baseband Transceiver and Baseband Processor
Page 16