Broadcom WICED BCM920737TAG-04, User Manual

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Power-Up Options
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August 27, 2015 • 920737TAG04-HWUM101-RDS Page 11
BCM920737TAG-04 WICED Smart Tag Hardware User Manual
Power-Up Options
VDDIO can be sourced from three options:
• Coin cell unregulated
• Coin cell regulated
• USB regulated
These options are set using SW2 and SW3 (see Figure 2 on page 9 ), as listed in Table 3 . The default regulator
output is 1.8V.
To adjust the regulator output, feedback components can be adjusted as shown in Table 4 .
UART Boot-Up
The following procedure describes how to power up the tag board with the UART interface enabled.
1. SW4 and SW5 should be placed in the desired power configuration, as shown in Table 3 .
2. SW6 should be in HCI mode by placing DIP switches 2 and 4 in the ON position (these positions are
considered standard until you wish to enter app mode).
3. Plug in the USB cable to connector J7 . The Smart Tag will display in the Windows Device Manager as two
COM ports named Silicon Labs Dual CP210x USB to UART Bridge: Enhanced COM Port (COM##),
where ## is the number of the assigned com port.
The evaluation board can now accept HCI commands or download firmware through the UART interface.
Table 3: Switch Settings for Power
Switch Coin Cell Unregulated Coin Cell Regulated USB Regulated
SW4 VUSB VCOIN VUSB
SW5 VCOIN VREG VREG
Table 4: Voltage Regulator Output
VOUT Component Values
3.3V RFB1 = 470 k Ω , RFB2 =150 k Ω , C22 = 100 pF
3.0V RFB1 = 330 k Ω , RFB2 = 120 k Ω , C22 = 150 pF
1.8V RFB1 = 300 k Ω , RFB2 = 240 k Ω , C22 = 150 pF
2.0V RFB1 = 360 k Ω , RFB2 = 240 k Ω , C22 = 150 pF
Note: If the device driver does not load correctly, the FTS2232H driver must be downloaded from the
FTDI website (see http://www.ftdichip.com/Drivers/VCP.htm ).
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