4117047
Rev 2.2
December 18, 2015
18
Product Technical Specification
Detailed Interface Specifications
2.1.3.
Burst Transmission Current Requirements
The power supply must be able to deliver high current peaks in a short time due to the burst
transmission nature of GSM. For supply filtering recommendations, please refer to section 2.3
Decoupling of Power Supply Signals.
The following table describes radio burst rates in connected mode. For detailed power consumption
figures, refer to section 2.4 Current DC Power Consumption.
Table 7.
Radio Burst Rates – Connected Mode
GSM/GPRS
Multislot Class
RF Power
Amplifier Current
Slot Duration
Period
Rising Time
Class 10
2.2A peak
577 μs
4.615 ms
10 μs
Class 12
The corresponding radio burst rates in connected mode are as follows:
GSM/GPRS class 2 terminals emit 577 µs radio bursts every 4.615 ms
GPRS class 10 terminals emit 1154 µs radio bursts every 4.615 ms
GPRS class 12 terminals emit 2308 µs radio bursts every 4.615 ms
In connected mode, the RF Power Amplifier current (2.2A peak in GSM /GPRS mode) flows with a
ratio of:
1/8 of the time (around 577 µs every 4.615 ms for GSM /GPRS cl 2 – 2RX/1TX), and
4/8 of the time (around 2308 µs every 4.615 ms for GSM /GPRS cl 12 – 4RX/1TX) with the
rising time at around 10 µs.
Figure 3.
Power Supply During Burst Transmission
