Use Instructions
Table Of Contents
- 1 About this document
- 2 Product Overview
- 3 Interface Description
- 3.1 PIN Definition
- 3.2 Operating condition
- 3.3 Digital I/O characteristics
- 3.4 Power Interface
- 3.5 UIM interface
- 3.6 PCM interface(TBD)
- 3.7 USB2.0 interface
- 3.8 UART Interface
- 3.9 Power on/off and reset interface
- 3.10 Interactive interface
- 3.11 Net Light interface
- 3.12 System boot configuration and download
- 3.13 Analog and Digital conversion (ADC) interface
- 3.14 I2C interface
- 3.15 SPI interface
- 3.16 Antenna interface
- 4 Product characteristics
- 5 Design guideline
- 6 Manufacturers
- 7 Package Storage information
- 8 Safety Information
L710HG Hardware Design
21
Figure 3-2 VBAT input application circuit
Note: The Cd, Ce, Cb, Cc and Cf are recommended being mounted for L710HG, but the Ca, Cb, Ce,
Cc and Cf for tune.
In addition, in order to get a stable power source, it is suggested to use a Zener diode of which reverse
Zener voltage is 5.1V and dissipation power is more than 500mW. Some zener diodes will have
leakage of 1uA, which will increase the power consumption in PSM mode.
Table 3-8: Recommended Zener diode models
NO.
Manufacturer
Part Number
Power
Package
1
On semi MMSZ5231BT1G 500mW SOD123
2
Prisemi PZ3D4V2H
500mW
SOD123
3
Vishay MMSZ4689-V
500mW
SOD123
4
Crownpo CDZ55C5V1SM
500mW
0805
3.4.4 Recommended Power supply circuit
If the voltage difference is not big, we recommend DCDC or LDO is used for the power supply of the
module, make sure that the peak current of power components can rise up to more than 800 mA. The
following figure is the reference design of +5V input linear regulator power supply. The designed
output for the power supply is 3.8V.
Figure 3-3 Reference circuit of the LDO power supply
If there is a big difference between the input voltage and the desired output (VBAT) or better
efficiency is more important, a switching converter power supply will be preferable. The following
figure is the reference circuit.