E7804BHF Semtech, E7804BHF Datasheet - Page 7

• Manufacturer Part Number: E7804BHF
• Manufacturer: Semtech

Specifications of E7804BHF

• Operating Temperature (max): 100C
• Package Type: MQFP
• Mounting: Surface Mount
• Lead Free Status / Rohs Status: Not Compliant

Driver Connect/Disconnect
The driver output connects to the VIO output pin through
an internal, normally open switch (S1). Refer to the
Functional Block diagram in Figure 1 for Switch S1. This
switch can be closed by serially programming the internal
register bit for the appropriate channel (see Table 2,
CH[0:3]_Relays_&_States registers) denoted as S1 to a
logical “1”. Logical “0” will open the switch. An external
pin, OPN[0:3] one input for each channel, is combined
with the register bit and will override the internal register
bit and Open the S1 switch for the channel. In its low
state, the OPN input will not override and force the switch
closed however. (It should be noted that OPN=1 will also
open S2 to disconnect the channel’s window comparators
from the VIO pin.) OPN is a fast way of disconnecting the
lower voltage driver and comparator circuitry from the VIO
pin. When the driver (and comparator) are disconnected,
the voltage at VIO may be in the range of the VEE to VXX
power supplies.
The high voltage disconnect switches permit an external
Parametric Measurement Unit (PMU) to be connected to
the VIO pin having a maximum range from VEE to VXX
volts and up to
This high voltage isolation also permits an external driver
to apply up to VXX volts (when switches S1 and S2 are
open) for high voltage applications.
Each driver may also be connected, internally, to EPMUS
in order to measure its output for purposes of calibrating
the DVH/L levels via switch S3.
TEST AND MEASUREMENT PRODUCTS
Circuit Description (continued)
2005 Semtech Corp. / Rev. 5, 12/6/05
OPN
DVL
DVH
HiZ
Table 1. Edge7804 Driver Modes of Operation
D
D
g i
E
1
1
0
0
(Open Channel Input)
(Driver Low)
(Driver High)
(High Impedance)
N
t i
l a
n I
p
D
u
0
1
0
1
I H
s t
40 mA.
S
1
D
C
V
D
H
H
V
o l
O I
L V
Z i
Z i
H
e s
O
d
P
N
=
0
S
1
O
O
O
O
Open (Driver, Comparator
X
S1
V
O
p
p
p
p
O I
n e
n e
n e
n e
p
e
n
open/disconnected)
(see Table 3)
(Don’t Care)
(Driver Output Switch)
O
O
O
O
O
P
V
N
p
p
p
p
X
O I
n e
n e
n e
n e
=
1
Comparator
Each channel’s two comparators, A and B, are combined
to form a window comparator to determine whether its
input, VINP , is above, below, or in between the two
comparator thresholds (CVA and CVB).
the positive input of both comparators.
The CVA/B inputs should be driven from low impedance
sources. There is an input non-linear current shift of
~15 A when the VINP signal to the comparator crosses
polarity with respect to the CVA/B input. If the source
impedance is too great, this could affect the accuracy of
the compare points. The voltage source’s output
impedance should be below 4K to avoid this. DAC or op
amp outputs will have no issue with this. (If resistor dividers
are used to create the CVA/B voltages, the voltage should
be buffered to prevent this shift.)
VINP has a range of –2V, +5.5V, but is restricted to the
range of the drivers whenever a comparator is connected
to its driver (S1 and S2 switches both closed), namely
0.2V, +5.2V.
The comparator outputs are differential LVDS compatible
on the QA/QA* and QB/QB* device pins. The output states
of the comparators for each channel can also be read
back using the serial interface. See Table 3,
CH[0:3]_switches_&_states read back instruction for the
individual channels.
Comparator Levels
Each channel’s CVA and CVB are the window comparator’s
two threshold levels. CVA and CVB are high impedance
voltage inputs that determine the thresholds at which the
window comparator changes state. CVA and CVB have a
range of –2.0V, +5.5V.
Comparator Connect/Disconnect
The window comparator input (VINP) connects to the VIO
pin through an internal switch (S2). This switch can be
closed to VIO by serially programming the internal register
bit for the appropriate channel (see Table 2,
CH[0:3]_switches_&_states registers) denoted as S2 to a
logical “1”. Logical “0” will open the switch from VIO. The
7
Edge7804
PRELIMINARY
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VINP is tied to
–