Preliminary Datasheet BM77SPPx3MC2 (Microchip) - 7

BM77SPPx3MC2
FIGURE 1-5: BM77 TO MCU INTERFACE EXAMPLE – BATTERY
Li-ion Battery
(3.7V) LDO (3.3V) BM77 Module
BAT_IN
(3.2 – 4.3V) 10uF MCU P15/STATUS_IND_1
P04/STATUS_IND_2 I/O
I/O SW_BTN
WAKEUP
RST_N I/O
I/O
I/O P37
P34
P33
P32
P31
P05 I/O
I/O
I/O
I/O
I/O
I/O LDO33_O
10uF VDD_IO (Note 1)
(2.8 – 3.63V)
NC LDO18_O Note 2 PMULDO_O
TXD
RXD P20
P24
EAN LED1 P12/SCL
P13/SDA
P36 System Configuration 1.12 Note 1 CTS
RTS P00/RTS
P17/CTS
NC VDD RX
TX
NC
NC
NC Note: 1. Ensure VDD_IO and MCU VDD voltages are compatible.
2. Control and indication ports are configurable. Mounting Details The BM77SPPS3MC2 physical dimensions are shown in Figure 1-6, recommended host PCB footprint in
Figure 1-7, and mounting suggestion in Figure 1-8. There should not be top copper layer near the test
pin area shown in Figure 1-7. When laying out the host PCB, the areas under the antenna should not
contain any top, inner layer, or bottom copper as shown in Figure 1-8. A low-impedance ground plane
will ensure best radio performance (best range, lowest noise). Figure 1-8 shows a minimum ground
plane area to the left and right of the module for best antenna performance. The ground plane can be
extended beyond the minimum recommended as need for host PCB EMC noise reduction. For best
range performance, keep all external metal away from the ceramic chip antenna at least 31 mm.
The BM77SPP03MC2 physical dimensions are shown in Figure 1-9, recommended host PCB footprint in
Figure 1-10, and mounting suggestion in Figure 1-11. It is highly recommended to layout the host PCB as
suggested in Figure 1-11. A low-impedance ground plane will ensure best radio performance (best
range, lowest noise). Pin 30 (BT_RF) is a 50 ohm connection to an external antenna connector, PCB
trace antenna, or component (ceramic chip) antenna through a host PCB 50 ohm micro-strip trace. This
trace can be extended to include passive parts for antenna attenuation padding, impedance matching,
or to provide test posts. It is recommended that the micro-strip trace be as short as possible for
minimum loss and best impedance matching. If the micro-strip trace is longer, it should be a 50 ohm
impedance. Figure 1-11 shows an example connection to U.FL connector. 1.13 Soldering Recommendations The BM77 wireless module was assembled using standard lead-free reflow profile IPC/JEDEC J-STD-020.
The module can be soldered to the host PCB using standard leaded and lead-free solder reflow profiles.
To avoid damaging the module, the following recommendations are given:
© 2014 ISSC Technologies Corp. Preliminary Revision 2.1.1 – June 16, 2015 Page 7