BC41B143A-DS-002PD Datasheet, PDF (64/89 Pages) List of Unclassifed Manufacturers – BlueCore 4-ROM CSP EDR Single Chip Bluetooth v2.0 + EDR System

Device Terminal Descriptions
BlueCore4-ROM CSP
PIO
USB_DP
USB_DN
USB_ON
1.5kΩ 5%
Rs 22 to 27Ω
Rs 22 to 27Ω
Rvb1 22kΩ 5%
Rvb2 47kΩ 5%
USB cable
D+
D-
VBUS
GND
Figure 11.12: USB Connections for Self Powered Mode
The terminal marked USB_ON can be any free PIO pin. The PIO pin selected must be registered by setting
PSKEY_USB_PIO_VBUS to the corresponding PIO number.
11.5.5 Bus-powered Mode
In bus-powered mode the application circuit draws its current from the 5V VBUS supply on the USB cable.
BlueCore4-ROM CSP negotiates with the PC during the USB enumeration stage about how much current it is
allowed to consume.
For Class 2 Bluetooth applications, CSR recommends that the regulator used to derive 3.3V from VBUS is rated
at 100mA average current and should be able to handle peaks of 120mA without foldback or limiting. In bus-
powered mode, BlueCore4-ROM CSP requests 100mA during enumeration.
When selecting a regulator, be aware that VBUS may go as low as 4.4V. The inrush current (when charging
reservoir and supply decoupling capacitors) is limited by the USB specification (see USB specification v1.1,
Section 7.2.4.1). Some applications may require soft start circuitry to limit inrush current if more than 10μF is
present between VBUS and GND.
The 5V VBUS line emerging from a PC is often electrically noisy. As well as regulation down to 3.3V and 1.8V,
applications should include careful filtering of the 5V line to attenuate noise that is above the voltage regulator
bandwidth. Excessive noise on the 1.8V supply to the analogue supply pins of BlueCore4-ROM CSP will result in
reduced receive sensitivity and a distorted RF transmit signal.
BlueCore4-ROM CSP
USB_DP
USB_DN
USB_ON
Rs 22 to 27Ω
D+
Rs 22 to 27Ω
D-
VBUS
GND
Voltage
Regulator
Figure 11.13: USB Connections for Bus-Powered Mode
Note:
USB_ON is shared with BlueCore4-ROM CSP PIO terminals.
BC41B143A-ds-002Pd
This material is subject to CSR’s non-disclosure agreement
Production Information
© Cambridge Silicon Radio Limited 2005
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