Overall Block Description; A1 Power Supply - Keysight N5171B EXG Service Manual

Troubleshooting

Overall Block Description

Overall Block Description
The objective of the overall block diagram is to provide a functional overview of
the Keysight N5171B/72B/73B EXG-B and N5181B/82B/83B MXG-B X-Series
signal generators. The major functional circuitry shown in the block diagram is
described in this section. Familiarize yourself with this information before you
start troubleshooting.
The overall block diagrams for the N5171B/81B and N5172B/82B are similar,
though individual hardware circuitry is very different. The N5171B/72B/73B
EXG-B hardware circuitry is based on a single-loop frequency synthesis design
similar to the design of the prior MXG-A signal generator; N5181A, N5182A,
N5183A. The N5181B/82B/83B MXG-B hardware circuitry improves the overall
phase noise of the product through the use of a triple-loop frequency synthesis
hardware design.
The overall capabilities are similar when comparing the N5171B/81B and the
N5172B/82B, except for the A2 Vector module. The A2 Vector Module controls
digital arbitrary circuitry operations in the N5172B/82B. Additionally, the
N5172B/82B with Option 660 contains the A7 Real Time Baseband Generator
(BBG) Assembly along with supporting/connecting hardware.
The N5173B and N5183B include an A7 Micro Deck and use different A3 RF
assemblies than those used in the RF models of the X-Series Signal
Generators, although the design characteristic of being a single loop for EXG
and a triple loop for MXG remains the same.
The following components are not shown in the overall block diagram, but are
described in this section.

— A1 Power Supply

— A5 CPU
— A6 Front Panel Interface Scan Assembly
— A7A1 Real Time Assembly Power Supply
— A8 Floating BNC Bypass (N5173B/N5183B)
— Front Panel
A1 Power Supply
The main power supply is a switching supply designed with an automatic
line-voltage and frequency selection. The supply has a maximum total output
power draw of 210 watts. The supply converts line voltage (120 Vac or 240
Vac) to regulated dc voltages. There is an internal power line fuse that is not
replaceable. If the fuse opens, the power supply must be replaced. All A1
Power Supply outputs, except for the 5.1SB (standby-supply), are over-current
protected and will not be damaged if a continuous short circuit occurs.
Keysight X-Series Signal Generators Service Guide 15