Vicor VI Chip PRM Evaluation Board - Manual (Page 23)

UG:013 vicorpower.com Applications Engineering: 800 927.9474 Page 23
Remote Sense operating mode using PRM ® and VTM ® :
non-isolated remote sensing (differential sensing)
Mode select switch S10 setting: keep the switch S10 setting at all positions as shown in
the following illustration.
Note: To use this configuration, the VTM isolation must be broken by tying VTM -IN and VTM -OUT
together.
The following table describes the switch configuration.
REMOTE SENSE (Differential)
ON
OFF
1 2 3 4 5 6 7 8 9 10
Postion
number
Switch
Position ON or OFF Connection
Number
1 ON TRIM pin is shorted to GND and PRM is configured for Remote Sense
Operating mode.
2 ON CONTROL NODE pin is connected to output of external error amplifier.
3 ON IFB pin is connected to output of external current sense amplifier to set the
constant current limit.
4 ON REF_EN pin is connected to input of the external voltage reference circuit to
generate voltage reference for external error amplifier.
5 ON VAUX pin is connected to power VCC of the op-amp and current sense IC.
6 OFF TM pin of the VTM is not connected to VT pin of the PRM.
7 OFF PRM +OUT pin is NOT connected to local sense (single ended) of the remote
sense control circuitry.
8 Don’t care
9 ON VTM +OUT (+SENSE) pin is connected to positive input (+SENSE_B) of the
differential buffer of remote sense control circuitry.
10 ON VTM –OUT (-SENSE) pin is connected to negative input (-SENSE_B) of the
differential buffer of remote sense control circuitry.
Table 7.
Switch configuration in
differential sensing
1206
1K
R36
SGND
SGND
VCC
R32
1206 C22
1206
C19
1206
EAO
R33
1206
SGND
R41
1206
+SENSE_B
-SENSE_B
LOCAL SENSE_+
2
3
1
4
8
SO8
U11A
6
5
7
U11B
1206
R29
1206
20K
R28
1206
4.7nF
C20
C21
0603
H 39 H 40
H 43 H 44 H 42 H 41 IMON
R27
1206
H 48 H 47
H 51 H 52
1206
R30
H 46 H 45
TP38 TP37
OPEN
OPEN
OPEN
1206
1.27K
R31
1206
1.27K
R42
VREF
To VTM ouput (+S/–S)
through S10 and J10
To CONTROL NODE
through S10
Preinstalled component
and connections
User installed
component
Figure 14.
Remote Sense: non-isolated
remote sensing (differential)
control circuitry
BLUE highlight =
Pre-installed component
GREEN highlight =
user installed component