Datasheet

3Maxim Integrated
Evaluates: MAX9633
MAX9633 Evaluation Kit
and INB- pads. Install a shunt on JU3 to ground the INB-
input in this configuration. The output voltage is given by
the following equation:
( )
OUT IN
R9
V 1V
R7

= +


Differential Amplifier
To configure op-amp U1-A as a differential amplifier,
replace R1–R4 with appropriate resistors and install a
shunt on jumper JU1. Make sure R1 = R4 and R2 = R3.
The CMRR of the differential amplifier is determined by
the matching of the resistor ratios R4/R2 and R1/R3:
where:
( )
OUT
V GAIN INP - INN
R4 R1
GAIN
R2 R3
=
= =
To configure op-amp U1-B as a differential amplifier,
replace R6–R9 with appropriate resistors and install a
shunt on jumper JU3. Make sure R6 = R9 and R7 = R8.
The CMRR of the differential amplifier is determined by
the matching of the resistor ratios R9/R7 and R6/R8:
( )
OUT
V GAIN INP - INN
R9 R6
GAIN
R7 R8
=
= =
where:
Transimpedance Application
To configure op-amp U1-A as a transimpedance
amplifier (TIA), replace R2 with a 0I resistor and install a
shunt on jumper JU2. The output voltage of the TIA is the
input current multiplied by the feedback resistor:
OUT IN BIAS OS
V (I I ) R4 V= + ×+
where R4 is installed as a 100I resistor, I
IN
is defined as
the input current source applied at the INA- pad, I
BIAS
is
the input bias current, and V
OS
is the input offset voltage
of the op amp. Use capacitor C6 (and C5, if applicable) to
stabilize the op amp by rolling off high-frequency gain
due to a large cable capacitance.
To configure op-amp U1-B as a TIA, replace R7 with a
0I resistor and install a shunt on jumper JU4. The output
voltage of the TIA is the input current multiplied by the
feedback resistor:
OUT IN BIAS OS
V (I I ) R9 V= + ×+
where R9 is installed as a 100I resistor, I
IN
is defined as
the input current source applied at the INB- pad, I
BIAS
is
the input bias current, and V
OS
is the input offset voltage
of the op amp. Use capacitor C9 (and C8, if applicable) to
stabilize the op amp by rolling off high-frequency gain
due to a large cable capacitance.
Capacitive Loads
Some applications require driving large capacitive loads.
To improve the stability of the amplifier in such cases,
replace R5 (R10) with a suitable resistor value to improve
amplifier phase margin. The R5/C7 (R10/C10) filter can
also be used as an anti-alias filter, or to limit amplifier
output noise by reducing its output bandwidth.