MT88E43B
MT88E43
Data Sheet
V
DD
St/GT
R1
C
V
D
=diode forward voltage
R2
ESt
(a) t
GP
> t
GA
t
GP
= R1C ln [V
DD
/(V
DD
-V
TGt
)]
t
GA
= R
P
C ln [(V
DD
-V
D
(R
P
/R2))/(V
TGt
-V
D
(R
P
/R2))]
R
P
= R1R2/(R1+R2)
MT88E43
V
DD
St/GT
ESt
R1
C
V
D
=diode forward voltage
R2
(b) t
GP
< t
GA
t
GP
= R
P
C ln [V
DD
-V
D
(R
P
/R2))/(V
DD
-V
TGt
-V
D
(R
P
/R2))]
t
GA
= R1C ln (V
DD
/V
TGt
)
R
P
= R1R2/(R1+R2)
Figure 5 - Guard Time Circuits with Unequal Times
Input Configuration
The MT88E43 provides an input arrangement comprised of an operational amplifier and a bias source (V
Ref
); which
is used to bias the opamp inputs at V
DD
/2
. The feedback resistor at the opamp output (GS) can be used to adjust
the gain. In a single-ended configuration, the opamp is connected as shown in Figure 6. For a differential input
configuration, Figure 7 shows the necessary connections.
IN+
C
R
IN
IN-
R
F
Voltage Gain
(A
V
) = R
F
/ R
IN
GS
V
Ref
Figure 6 - Single-Ended Input Configuration
8
Zarlink Semiconductor Inc.