SMSC EVB-EMC2101 - Manual (Page 10)

EVB-EMC2101 User Manual
Revision 1.5 (12-13-06) SMSC EMC2101
10
3.9.3 Remote Diode
The remote diode on board the EMC2101 EVB has a heater and an optional in-line series resistance
adjustment. Checking the REC feature of the EMC2101 is accomplished by removing the jumper on
JP7. This adds 100 ohms of series resistance to the DN line of the diode connection. To return to 0
ohm series resistance, replace the jumper on JP7.
To heat the diode, place a jumper on JP10. To return to ambient conditions, remove JP10. These
remote diode options are summarized in
Table 3.4 below.
This EVB also allows for an off-board diode to be tested (see Table 3.5 ). This is done by removing
both jumpers on JP8. Then connect Pin 1 to the ‘remote+’ terminal of the remote diode and Pin 3 to
the ‘remote-‘ terminal of the remote diode. Make sure a common ground exists between the remote
diode (GPU, etc.) and the EMC2101 EVB. Also ensure that the remote diode is properly biased
according to the diode manufacture.
A unique feature of the EMC2101-R device is the ability to start in one of several different
configurations based on the pull up resistor on the ALERT output. The EVB allows the user to quickly
evaluate each of the 4 configurations by adjusting JP11 as shown in
Table 3.6 . When using the auto
load via EEPROM, ensure that the Autorefresh Registers is not selected until the loading is complete
(less than 1 sec).
Table 3.4 Remote Diode Settings
JUMPER NAME OPEN SHORT
JP7 REC Q11 - 100 ohms in
DN line (diode remote -)
Q11 - 0 ohms in
DN line (diode remote -)
JP13 REC Q12 - 100 ohms in
DN line (diode remote -)
Q12 - 0 ohms in
DN line (diode remote -)
JP10 HEATER Ambient temp on remote diode
(Q12)
1.0W resistive heater on remote diode (Q12)
Table 3.5 Remote Diode Configurations
CONFIGURATION JUMPER PIN 1 PIN 2 PIN 3 PIN 4
On-board diode (Q11) JP9 short / DP short / DN
Off-board diode (CPU,
GPU, etc.)
JP9 remote + / DP open remote - / DN open
On-board diode (Q12) JP12 short / DP short / DN
Off-board diode (CPU,
GPU, etc.)
JP12 remote + / DP open remote - / DN open