User's Manual
Bluegiga Technologies Oy
Preliminary – information subject to change
Page 15 of 27
4 Design Guidelines
4.1 General Design Guidelines
BLE112 can be used directly with a coin cell battery. Due to relatively high internal resistance of a coin cell
battery it is recommended to place a 100uF capacitor in parallel with the battery. The internal resistance of a
coin cell battery is initially in the range of 10 ohms but the resistance increases rapidly as the capacity is used.
Basically the higher the value of the capacitor the higher is the effective capacity of the battery and thus the
longer the life time for the application. The minimum value for the capacitor depends on the end application
and the maximum transmit power used. The leakage current of a 100uF capacitor in in the range of 0.5 uA to
3 uA and generally ceramic capacitors have lower leakage current than tantalum or aluminum electrolytic
capacitors.
Optionally TI’s TPS62730 can be used to reduce the current consumption during TX/RX and data processing
stages. TPS62730 is an ultra low power DC/DC converter with by-pass mode and will reduce the current
consumption during transmission nominally by ~20% when using 3V coin cell battery.
A ferrite bead is recommended to be used to filter any excessive noise in the power supply lines to guarantee
the radio performance.
OPTIONAL DC/DC
PROGRAMMING INTERFACE
1
2
U4
BATTERYHOLDER_SMD_CR2032
C15
100uF/6.3V/X5R
1
STAT
2
SW
3
VIN
4
GND
5
ON/BYP
6
VOUT
U5
TPS62730
C10
2.2uF/10V/X5R
C11
2.2uF/10V/X5R
L1
2.2μH±20%, 130mA, 0.43ohm
1
GND
2
AVDD
3
AVDD
4
P2_2
5
P2_1
6
P2_0
7
P1_7
8
P1_6
9
DVDD_USB
10
GND
11
USB+
12
USB-
13
P1_5
14
P1_4
15
P1_3
16
P1_2
17
P1_1
18
P1_0
19
P0:7
20
DVDD
21
GND
22
P0_6
23
P0_5
24
P0_4
25
P0_3
26
P0_2
27
P0_1
28
P0_0
29
RESET
30
GND
MOD2
BLE112-A
1
3
5
2
4
6
78
910
J1
HEADER_2X5_SMD_1.27MM
C3
1uF/16V/X5R
C5
1uF/16V/X5R
C6
1uF/16V/X5R
P1_7/DCDC
VBAT
P2_2
2V...3V3_SW
P2_1
RESET_N
RESET_N
P2_2
P2_1
P1_7/DCDC
Figure 9: Example schematic for BLE112 with a coin cell battery
1
VBUS
2
D-
3
D+
4
NC
5
GND
7
8
6
9
J10
CON-MINIUSB-SOCKET-SMD
C20
0.47uF/6.3V/X5R
C31
2.2uF/10V/X5R
C32
2.2uF/10V/X5R
3
VIN
2
VOUT
1
GND
P1
MCP1700T-3302E/T
L4
FB 1kohm
1
2
R13
33R, 50V, 0.063W
1
2
R14
33R, 50V, 0.063W
1
2
R15
1.5K, 50V, 0.063W
C127
47pF/50V/C0G
C128
47pF/50V/C0G
1
GND
2
AVDD
3
AVDD
4
P2_2
5
P2_1
6
P2_0
7
P1_7
8
P1_6
9
DVDD_USB
10
GND
11
USB+
12
USB-
13
P1_5
14
P1_4
15
P1_3
16
P1_2
17
P1_1
18
P1_0
19
P0:7
20
DVDD
21
GND
22
P0_6
23
P0_5
24
P0_4
25
P0_3
26
P0_2
27
P0_1
28
P0_0
29
RESET
30
GND
MOD3
BLE112-A
C7
1uF/16V/X5R
C8
1uF/16V/X5R
C9
1uF/16V/X5R
RESET
Figure 10: Example schematic for BLE112 with USB