Top: +1.5 kV HV pulse
Bottom: Logic out into open circuit
HCPL-2601, R2 = 1kΩ, R6/9/10 = 0,
100 ns/div
Top: -1.5 kV HV pulse
Bottom: Logic out into open circuit
HCPL-2601, R2 = 1kΩ, R6/9/10 = 0,
100 ns/div
Unfortunately, this makes it difficult to determine which transients are due to glitches
transmitted inside the DUT and which are due to external capacitive coupling. This is an
unavoidable consequence of using an open-collector device. It will also be an issue for
optocouplers with totem-pole output circuits, if the current drive ratings of these outputs
are on the order of tens of milliamps or less – the capacitively-coupled current may still
overwhelm the output transistor current.
Some optocouplers have output circuits intended for gate-drive applications. These ICs
typically have very high output current ratings (or, equivalently, very low output
impedances). For instance, the VO3120 can source or sink 2.5 Amps. As a result, they
capacitively coupled signals are much smaller. For example, if an VO3120 is tested
using R4/6/9/10 = 0Ω, the following outputs are obtained:
Top: +1.5 kV HV pulse
Bottom: Logic out into open circuit
VO3120, R2 = ∞, R4/6/9/10 = 0,
100 ns/div
Top: -1.5 kV HV pulse
Bottom: Logic out into open circuit
VO3120, R2 = ∞, R4/6/9/10 = 0,
100 ns/div
64
Summary of Contents for AVRQ-5-B
Page 52: ...Bottom side 52 ...
Page 57: ...PCB 299B FOR ADUM241E0BRWZ 57 ...
Page 82: ...PCB 158R2 LOW VOLTAGE POWER SUPPLY ...
Page 87: ...DUT WIRING ON STANDARD DAUGHTERBOARD PCB 267C ...
Page 88: ...DUT WIRING ON CUSTOMIZED TLP2366 DAUGHTERBOARD PCB 298B ...
Page 89: ...DUT WIRING ON CUSTOMIZED ADUM241E0BRWZ DAUGHTERBOARD PCB 299B ...
Page 91: ...PERFORMANCE CHECK SHEET 91 ...
