TNY264P_1 POWERINT [Power Integrations, Inc.], TNY264P_1 Datasheet - Page 14

• Manufacturer Part Number: TNY264P_1
• Description: 2.4W Cell Phone Charger
• Manufacturer: POWERINT [Power Integrations, Inc.]

DER-4
2.4W Cell Phone Charger
February 4, 2004
7.4 Output Ripple Measurements
7.4.1 Ripple Measurement Technique
For DC output ripple measurements, a modified oscilloscope test probe must be utilized
in order to reduce spurious signals due to pickup. Details of the probe modification are
provided in Figure 8 and Figure 9.
The 5125BA probe adapter is affixed with two capacitors tied in parallel across the probe
tip. The capacitors include one (1) 0.1 µF/50 V ceramic type and one (1) 1.0 µF/50 V
aluminum electrolytic. The aluminum electrolytic type capacitor is polarized, so proper
polarity across DC outputs must be maintained (see below).
Probe Ground
Probe Tip
Figure 8 – Oscilloscope Probe Prepared for Ripple Measurement.
(End Cap and Ground Lead Removed)
Figure 9 – Oscilloscope Probe with Probe Master 5125BA BNC Adapter
(Modified with wires for probe ground for ripple measurement, and two parallel decoupling capacitors
added).
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