User Guide

GM47/48 Design Guidelines
BA/SEM/MSC 02:0006 Rev PA1 11
3.3.2 General Recommendations
The power supply conditions for the GM47/48 Vcc connection are as
follows:
Maximum voltage drop during
transmit burst
200mV
Maximum Ripple TBD : [estimate 50mV]
Table 3.1
Recommended ESR on CBULK : <100mΩ
Recommended Maximum DC resistance between PSU and GM47 Vcc
: <200mΩ
Recommended minimum CBULK : 1000µF [see tables below]
The following tables provide a quick indication to recommended
CBULK capacitance to maintain Vcc drop <200mV for different PSU
current delivery and DC resistance between PSU and Module Vcc.
C
BULK
ESR = 50mΩ
R
LINE
= 50mΩ
PSU LIMIT CBULK (min)
Transmit Burst
Vcc Dip (approx)
≥ 2.0 Amp 1000µF
120mV
1.5 Amp
*2500µF
170mV
1.0 Amp
*6000µF
160mV
0.5 Amp *10000µF 165mV
Table 3.2
C
BULK
ESR = 50mΩ
R
LINE
= 100mΩ
PSU LIMIT CBULK (min)
Transmit Burst
Vcc Dip (approx)
≥ 2.0 Amp 1500µF
200mV
1.5 Amp 4000µF 150mV
1.0 Amp
*6000µF
170mV
0.5 Amp
*10000µF
180mV
Table 3.3
C
BULK
ESR = 50mΩ
R
LINE
= 150mΩ
PSU LIMIT CBULK (min)
Transmit Burst
Vcc Dip (approx)
≥ 2.0 Amp 4000µF
200mV
1.5 Amp
5000µF
190mV
1.0 Amp
*6000µF
190mV
0.5 Amp
*10000µF
200mV
Table 3.4