AVTECH ELECTROSYSTEMS AVRQ-4-B, Instructions Manual

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The user will need to configure R1-R11 and C6 as appropriate for the DUT.
Two solder pads (P1 and P2 in the schematic, both are labeled “CAP” on the actual
PCB) are not used when the daughterboard is used with the AVRQ-4-B. (They are for
use with the related AVRQ-5-B model.)
Lastly, components C9, R12, R13 and J6 provide an optional logic probe point on the
daughterboard. J6 is installed by default (as shipped from the factory), but C9, R12, and
R13 are not. If a direct connection is desired from the DUT logic output to J6, then zero
Ohm jumpers can be installed in the C9 and R13 positions. R12 and R13 can also be
used to implement a resistive divider, if it is necessary to reduce the amplitude of a high-
voltage logic signal so that a low-voltage differential probe can be used. C9 may be used
to provide AC-coupling, if desired. The exact implementation of this optional circuitry is up
to the user. J6 is accessed through the LOGIC OUT “B” hole on the DUT door. The
LOGIC OUT “A” connector remains active regardless of the use of J6.
The design files for the sample daughterboard (Avtech PCB 267D) are available for
download at
https://www.avtechpulse.com/semiconductor/avrq-4/#support_files .
The function of the various components is summarized below:
Reference Footprint Installed Value
Normally
Modified
by User
Typical Function
C1 1206 2.2uF,50V,X7R
No
VCC1 decoupling
C2 RAD5 33uF,50V VCC2 decoupling
C3 0805 0.1uF VCC2 decoupling
C4 0805 0.1uF VCC1 decoupling
C5 0805 0.01uF VCC1 decoupling
C7 0805 0.1uF VCC1 decoupling
C8 1206 2.2uF,50V,X7R VCC1 decoupling
U1 DP8A-SOCKET DIP8 SOCKET DUT socket
J1 SIP16A-WIDER CONN16 Mates with socketing, some pins removed
J2 SIP16A-WIDER CONN16 Mates with socketing, some pins removed
J3 SIP4A-WIDER CONN4 Mates with socketing
J4 SIP4A-WIDER CONN4 Mates with socketing
J5 SIP4A-WIDER CONN4 Mates with socketing
U2 SOT23-5 LP2985-50DBVR Low-dropout 5V regulator VCC1
C6 0805 - Yes Load capacitance
R1 - Zero-Ohm Jumper to connect DUT pin 1 to VCC1
R2 - Output pullup
R3 -
Resistance to connect DUT pin 2 to VCC1.
Non-zero resistance for current-drive inputs.
R4 - Zero-Ohm Jumper for DUT pin 7 as logic output
R5 - Resistance to connect DUT pin 3 to VCC1
R6 - Zero-Ohm Jumper for DUT pin 6 as logic output
R7 - Resistance to connect DUT pin 4 to VCC1
R8 - Zero-Ohm Jumper to connect DUT pin 1 to GND1
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