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In GSM and GPRS applications, the capacitor supplies the pulse current to the transmitter and is charged by low current during the period between the pulses.
GSM Vdrop=I*ESR+(I*0.577mSec)/CmF
GPRS Vdrop=I*ESR+(I*1.154mSec)/CmF
In accordance with Ohm’s Law, current will be split inversely to the resistance
IR / ESR ratio, hence I=2*IR/(IR+ESR) Amp will be supplied from the supercapacitor, 2-IAmp supplied by the source.
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CLG03P035L28 |
CLG05P025L28 |
CLG03P020L17 |
CLG03P070L28 |
| Rated Capacitance |
36 |
23 |
20 |
72 |
| Available* Capacitance |
18 |
11 |
10 |
36 |
| Working Voltage |
3.5 |
5.5 |
3.5 |
3.5 |
| ESR mOhm |
100 |
145 |
115 |
45 |
| I source |
0.5 |
0.65 |
0.55 |
0.26 |
| I capacitor |
1.5 |
1.35 |
1.45 |
1.74 |
| Size |
28 x 17 x 2.2 |
28 x 17 x 3.4 |
17 x 17 x 2.8 |
28 x 17 x 2.8 |
| Vdrop GSM |
0.198 |
0.266 |
0.250 |
0.106 |
| Vdrop GPRS |
0.246 |
0.337 |
0.333 |
0.134 |
IR Source ~300mOhm
*Available capacitance under these pulse conditions The current drained from the voltage source is 0.5A, which is less than 0.606A specified in Mini PC.
Conclusions :
The supercapacitor reduces the peak current drawn from the voltage source. ESR to IR (source) ratio governs the current ratio. It is important to note that when the source is a battery, the supercapacitor protects the battery from oxidizing the electrodes.
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