2005-04-20
Below is a table of measurements showing the drain quiescent current (IDDQ) versus VGG. All measurements made at VDD = 13,8 V.
It seems that the spread is rather big and much higher than expected. A variation in IDDQ of 10% or so for the same VGG was expected. The consequence might be that the capabilities of the control loop must be extended.
| Measured by | Batch | Setup | IDDQ [mA] | |||
| At VGG = 3,5 V | At VGG = 4,0 V | At VGG = 4,5 V | At VGG = 5,0 V | |||
| OZ2M | 032XA | PA | - | 110 | 520 | 1550 |
| OZ1BGZ | 03XXA | PA | 330 (3,9 V) | 450 | 1500 | 3000 |
| OZ1DJJ | 032XA | PA | 1400 (4,7 V) | |||
| GW8IZR | 034XA | PA | 6 | 62 | 438 | 1600 |
| OZ1TF | 03XXA | PA | 100 | 700 | 1900 | 3200 |
| OZ2M | 03XXA | DC | 113 | 560 | 1750 | - |
| OZ2M | 03XXA | DC | 110 | 600 | 1680 | - |
| OZ2M | 03XXA | DC | 19 | 130 | 698 | 1940 |
| OZ9FW | 03XXA | PA | 400 (3,8 V) | 700 | 1950 | - |
| PA5DD | 03XXA | PA | 240 (3,6 V) | 690 | 1780 | 3100 |
"RA30H0608M is using MOSFET designed for the HF band. These "HF band" MOSFETs have a large distribution of Vthreshold, and distribution range is 2,0 V (actual value is approximately 2,0 V to 4,0 V).
Therefore I think the results the customer evaluated are right.
We recommend you adjust IDDQ by controlling VGG when using digital and AM/SSB modulation."
Bo, OZ2M, www.rudius.net/oz2m