E4717DBG SEMTECH [Semtech Corporation], E4717DBG Datasheet - Page 8

• Manufacturer Part Number: E4717DBG
• Description: Quad Channel, Per Pin Precision Measurement Unit
• Manufacturer: SEMTECH [Semtech Corporation]

Test Head Ground Reference
The Edge4717D features a test head ground referencing
feature which allows the force voltage function to be
referenced to a separate ground reference other than the
ground (GND) power used for the device. The test head
ground should be connected to the DUT_GND pin of the
Edge4717D. The maximum allowed variation between
DUT_GND and GND is
Force Voltage Mode
In the FV mode (FV/FI* = 1), VINP is a high impedance,
analog voltage input that maps directly to the voltage forced
at the FORCE pin.
Measure Current Mode
In the MI mode (MI/MV* = 1), a current monitor is
connected in series with the PMU forcing amplifier. This
monitor generates a voltage that is proportional to the
current passing through it, and is brought out to IVMON.
This voltage (corresponding to the measured current) can
also be tested by the on-board window comparator.
Force Current Mode
In the FI mode (FV/FI* = 0), VINP is a high impedance,
analog voltage input that is converted into a current at
the FORCE pin (see Figure 1) using the following
relationship:
where VREF is the reference voltage input at the REF pin
which is nominally set at 2.25V. (Positive current is de-
fined as current flowing out of the PMU.) Table 6 de-
scribes the relationship between the voltage applied to
VINP and the current at FORCE for Ranges A, B, and C.
TEST AND MEASUREMENT PRODUCTS
Circuit Description (continued)
2005 Semtech Corp. / Rev. 5, 10/14/05
Forced Current =
E T
0
1
S
T
Table 5.
250 mV.
E T
S
_ T
N
(REXT * 2.5)
VINP – VREF
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8
In the Force Current mode, the voltage at VINP is divided
by 2.5 internally on the chip, so that a
internally for forcing currents on Ranges A, B, and C. Range
D uses a
Measure Voltage Mode
In the MV mode (MI/MV* = 0), DUT voltage is measured
via the SENSE input pin. This measured voltage can be
displayed on the IVMON pin and tested using the internal
window comparator.
Comparator
The Edge4717D features an on-board window compara-
tor which provides two-bit measurement range classifica-
tion. IVMAX and IVMIN are high impedance analog inputs
that establish the upper and lower thresholds for the win-
dow comparator. COMP_IN is the window comparator in-
put pin. COMP_IN should be connected to IVMON on
each channel if it is desired to use the comparator to
indicate PMU measurements.
In the MI mode, an I/V MAX input of +2V will set the
upper threshold of the window comparator to a voltage
corresponding to +FSC (full-scale current), and an I/V MIN
input of –2V will set the lower threshold to a voltage
corresponding to –FSC for Ranges A, B, and C. Similarly
for Range D, –1.2V corresponds to sinking full-scale
current, and +1.2V corresponds to sourcing full-scale
current (positive current is defined as current flowing out
of the PMU).
DUTGTL the DUTLTH are LVTTL compatible outputs which
indicate the range of the measured parameter in relation
to IVMIN and IVMAX. Comparator functionality is sum-
marized in Table 7.
V
V
V
V
R
R
R
R
F E
F E
F E
F E
1.2V range across REXT for forcing currents.
V
V
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+
–
–
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P
3
5
5
3
5 .
5 .
5 .
5 .
V
V
V
V
Table 6.
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