User's Manual

Enhanced Class 1 Bluetooth v2.1 Module
User’s Guide
Americas: [phone] Option 2
Europe: [phone]
Hong Kong: [phone]
www.lairdtech.com/wireless
9
CONN-GUIDE-BT740_v0.2
 GPIO3 is also used for DTR output (active low). See S Registers 552 and 553.
 Analogue 0 and 1 should not exceed 1.8 V and are accessible through S Registers 701 and 702.
2.4 Electrical Specifications
2.4.1 Absolute Maximum ratings
Absolute maximum ratings for supply voltage and voltages on digital and analogue pins of the module are
listed below.
WARNING: Exceeding the following values causes permanent damage to the device.
Parameter
Min
Max
Unit
Peak current of power supply
0
200
mA
Voltage at digital pins
-0.4
3.7
V
Voltage at POWER pin
2.9 *
6.0
V
2.4.2 Recommended Operating Parameters
2.4.2.1 Power Supply
Signal
Name
Pin No
I/O
Voltage level
Comments
VCC_VIN
11
I
3.0 V to 5.0 V *
Typ 3.3 V
I
typ
= TBC mA?
GND
1, 12, 15,
20, 34, 36
6 Ground terminals to be attached in
parallel
VCC_3V3
13
O
3.3 V typical
For monitoring only. No current source
Note: VCC_3V3 refers to internal voltage generated by the LDO inside the module (typically 3.3 V).
Internal LDO drop is 0.2 V. To achieve 3.3 V for VCC_3V3 requires VCC_IN of 3.5V. IO voltage
levels follow VCC_3V3.
2.4.2.2 Signal Levels for Interface, PCM, SPI, and GPIO
Signal Type
Signal level
Signal level at 0 mA load
Input
VILmin= -0.4V
VILmax=0.8V
VIHmin=2.3V
VIHmax=3.7V
Output
VOLmax=0.2V
VOHmin=3.1V
2.4.2.3 RS-232 Interface
Signal Name
Pin No
I/O
Comments
UART_TX
23
O