In-Circuit Tester – N5747A High-Power Power Supply

Overview

This paper discusses the first successful implementation of the Keysight Technologies, Inc. N5747A high-power power supply on a customer product – a networking board project. At the time of writing, this networking board project was an existing project running mass production on a Keysight Medalist i3070 Series 5 in-circuit tester, requiring a +12 V @ 18 A input power supply.

In the previous setup, 6 x 6624 and 1 x 6642 power supplies were wired in paral­lel inside the fixture to achieve the +12 V @ 18 A requirement.

The N5747A is a single-output programmable DC power supply in a compact package, capable of driving up to 50 V @ 10 A (500 W). The N5747A power sup­ply can only be connected to Channel 3 and Channel 4 on the Keysight ASRU-N card, or Channel 7 and 8 on the Keysight utility card.

Two N5747A modules were used to replace all the 6624 and 6642 power supplies.

The existing fixture and test program were modified slightly to cater for N5747A power supplies. Five hundred boards were tested successfully with N5747A power supplies.

Cost-savings in term of power supply module, reduction of fixture wiring effort and increased efficiency of the power supply modules will be discussed.

N5747A Setup

Two modules of N5747A power supply were installed into the support bay. A new power supply monster cable was required to handle the higher current capability of the N5747A power supply. For simplicity, thicker core wires were used in the new power supply monster cable.

The Keysight 3070 software on the customer’s tester was upgraded from revi­sion 08.00p to 08.20p. New syntax for N5747A power supply was implemented in 08.20p, with module pin assignment enhanced to assign wiring resources for N5747A automatically. In this way, the fixture vendor could continue to fabricate and wire up the fixture and power supply resources correctly based on the fixture file.

Minor modification was done to the existing fixture to accommodate for the new N5747A power supplies. On the ASRU-N card, four additional BRC resources on the second row of pins were allocated for each of Channel 3 and Channel 4 outputs. On the ASRU-C card, we had six BRC resources (Low, Low, High, High, Sense-Low and Sense-High) for each channel. The additional four BRC resources (Low, Low, High and High) were to handle the extra current involved for N5747A.

Summary: Benefits of the N5747A Power Supply

1. The N5747A power supply can drive up to 50 V @ 10 A, 500 W

2.  The N5747A will be connected to Channel 3 or 4 of the ASRU-N card or to Channel 7 and/or 8 of the Utility card

3. With N5747A upgrade to Channel 3 or 4, the existing four outputs from a 6624 power supply can be connected to Channel 1, 2, 5 and 6 on the ASRU-N card

4. A new power supply monster cable is used to handle the higher current rating