SLUU085 – November 2001
7
UCC3580EVM
4
Test Setup and Test Points
AC
LINE
AC
HIGH
AC
NEUTRAL
ISOLATION
TRANSFORMER
1:1
VARIAC
SAFETY
GROUND
1.2
Ω
, minimum
120 Watts
10 Amps
Oscilloscope
Tektronix
TDS460A
Tektronix
P5205
100MHz
High Voltage
Differential
Probe
+
–
Tektronix
P5100 100X
Probe,
2500V,peak
Tektronix
P6138A
10X Probe,
300V,peak
1
2
3
NOTES:
1
2
3
Warning, High Voltage!
This test setup is connected to the ac
line, observe isolation requirements.
Use the P5202 for all differential observations,
both high and low voltage.
Use the P5100 for all voltage observations that
are more than 200V and ground referenced.
Use the P6138A for all voltage observations
that are less than 200V and ground
referenced.
J1–1
Chassis
J1–2
Neutral
J1–3
Line
J2–2
GND2
J2–1
+12V
Demonstration
Hand–Held DVM
+
–
UCC3580EVM
Figure 1. Recommended Test Setup for the UCC3580EVM
Table 1. List of Test Points
Test Point
Signal Name
Voltage Range
GND REF
Measurement
TP1
GND2
SEC
Secondary ground
TP2
12 V
12 V
SEC
12 V, observe relative to TP1
TP3
TP4
TP5
12 V, 0.1 VAC
SEC
Injection and observation points for control loop. Refer to [1]
TP6
TP7
TP8
12 V
50 V
50 V
SEC
Differentially observe V(D17) between TP6 and TP8.
Differentially observe snubber power between TP6 and TP7.
TP9
PRI GND
PRI
Primary ground for controller observations
TP10
OUT1
12 V
PRI
Main MOSFET (QM) gate control signal
TP11
OUT2
12 V
PRI
Auxiliary MOSFET (QA) gate control signal
TP12
EAOUT
5 V
PRI
Error amplifier output to PWM comparator
TP13
PRI GND
PRI
PRI GND reference for QM and CSENSE observations
TP14
DRAIN
300 V
PRI
Observe QM drain voltage relative to PRI GND
TP15
CSENSE
1 V
PRI
Observe drain current of QM
TP16
TP17
TP18
SOURCE
BULK
DRAIN
300 V
300 V
300 V
PRI
Differentially observe QA drain–source voltage between TP18 and
TP16
Differentially observe clamp voltage, V(C25) between TP18 and TP17
TP19
TP20
PRI GND
BULK
200 V
PRI
Observe bulk capacitor voltage ( the dc input voltage to the converter)
