LM5085EVAL/NOPB National Semiconductor, LM5085EVAL/NOPB Datasheet - Page 5

• Manufacturer Part Number: LM5085EVAL/NOPB
• Description: EVAL BOARD FOR LM5085
• Manufacturer: National Semiconductor

Specifications of LM5085EVAL/NOPB

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

C) Lowest Cost Configuration: This configuration is the
same as option B above, but with C5 removed. The ripple at
the FB pin is attenuated from that at V
resistors (R1, R2). Since
pin, R6 is chosen to generate
minimum ripple current in this circuit is 116 mAp-p the mini-
Monitor The Inductor Current
The inductor’s current can be monitored or viewed on a scope
with a current probe. Remove the jumper from the WIRE
LOOP pads, and install an appropriate current loop across the
pads. In this way the inductor’s ripple current and peak current
can be accurately determined.
≥
25 mVp-p are required at the FB
≥
100 mV at V
FIGURE 7. Complete Evaluation Board Schematic
OUT
by the feedback
FIGURE 6. Lowest Cost Configuration
OUT
. Since the
5
mum value for R6 calculates to 0.86 ohms. Using a standard
value 1.0 ohms resistor for R6, the ripple at V
≊
See Figure 11. If the application can accept this ripple level,
this is the most economical solution. The circuit is shown in
Figure 6.
Scope Probe Adapters
Scope probe adapters are provided on this evaluation board
for monitoring the waveform at the SW node, and at the
circuit’s output (V
which can pick up noise from the switching waveforms. The
probe adapters are suitable for Tektronix P6137 or similar
probes, with a 0.135” diameter.
116 mVp-p to
≊
OUT
1190 mVp-p over the input voltage range.
), without using the probe’s ground lead
30072013
OUT
ranges from
www.national.com
30072014