E818AHF View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'E818AHF' PDF : 12 Pages View PDF
Edge818
TEST AND MEASUREMENT PRODUCTS
Circuit Description
VH
Driver Description
The Edge818 supports programmable high and low levels
and tristate per channel. There are no shared lines
between any drivers. The EN* and DATA signals are wide
voltage high impedance analog inputs capable of receiving
digital signals over a wide common mode range. VBB is
the high impedance analog input which sets the threshold
for EN* and DATA.
EN*, DATA
> VBB
< VBB
Status
"1"
"0"
DUT
VL
Figure 1. Simplified Model of the
Unbuffered Output Stage
With EN* high, the driver goes into a high impedance state.
With EN* low, DATA high forces the driver into a high state,
and DATA low forces the driver into a low state.
EN* DATA
1
X
0
1
0
0
DOUT
HiZ
VH
VL
Drive High and Low
VH and VL define the logical "1" and "0" levels of the driver,
and can be adjusted anywhere over the range determined
by VCC and VEE. There are no restrictions between VH
and VL, other than they must remain within the power
supply levels.
VEE ≤ VH ≤ VCC
VEE ≤ VL ≤ VCC
The VH and VL inputs are unbuffered in that they also
provide the driver output current (see Figure 1), so the
source of VH and VL must have ample current drive
capability.
Driver Output Protection
In a functional testing environment, where a resistor is
added in series with the driver output to create a 50Ω
driver, the Edge818 can withstand a short to any legal
voltage for an indefinite amount of time.
In a low impedance application, with no additional output
resistance, the system should be designed to check for a
short circuit prior to connecting the driver, and tristate the
driver if a short is detected.
Receiver Description
The Edge818 supports a window comparator with
independent threshold levels per channel. There are no
shared comparator lines between channels. CVA and CVB
are high impedance analog voltage inputs which define
the threshold voltages for comparators A and B.
If VINP is more positive than CVA or CVB, QA and QB will
be high. Otherwise, QA and QB will be low.
VINP
VINP > CVA
VINP < CVA
QA
COMP HIGH
COMP LOW
VINP
VINP > CVB
VINP < CVB
QB
COMP HIGH
COMP LOW
2004 Semtech Corp. / Rev. 5, 8/18/04
4
www .semtech.com
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