MAX4146ESD-T Maxim Integrated, MAX4146ESD-T Datasheet - Page 11

• Manufacturer Part Number: MAX4146ESD-T
• Description: Special Purpose Amplifiers
• Manufacturer: Maxim Integrated
• Series: MAX4144, MAX4145, MAX4146r

Specifications of MAX4146ESD-T

• Number Of Channels: Single
• Common Mode Rejection Ratio (min): 80 dB
• Input Offset Voltage: 0.6 mV
• Maximum Power Dissipation: 667 mW
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C

• Do not use IC sockets—they increase parasitic
• Use surface-mount power-supply bypass capacitors
• Keep signal lines as short and as straight as possi-
• The ground plane should be as free from voids as
Under short-circuit conditions to ground, limit the out-
put current to 120mA. This level is low enough that a
short to ground of moderate duration will not cause per-
manent damage to the chip. However, a short to either
supply will significantly increase power dissipation, and
will cause permanent damage. The high output current
capability is an advantage in systems that transmit a
signal to several loads.
The MAX4144/MAX4145/MAX4146 include internal pro-
tection circuitry that prevents damage to the precision
input stage from large differential input voltages. This
protection circuitry consists of five back-to-back
Schottky protection diodes between IN+ and RG+, and
IN- and RG- (Figure 1). The diodes limit the differential
voltage applied to the amplifiers’ internal circuitry to no
more than 10V
age drop (about 0.4V at +25°C).
Figure 1. Input Protection Circuits
capacitance and inductance.
instead of through-hole capacitors. Their shorter
lead lengths reduce parasitic inductance, leading to
superior high-frequency performance.
ble. Do not make 90° turns; round all corners.
possible.
IN-
IN+
F
Output Short-Circuit Protection
, where V
______________________________________________________________________________________
Input Protection Circuitry
1.4k
F
is the diode’s forward volt-
MAX4144
High-Speed, Low-Distortion,
Differential Line Receivers
For a large differential input voltage (exceeding 4V), the
MAX4145/MAX4146 input bias current (at IN+ and IN-)
increases according to the following equation:
The MAX4144 has an internal gain-setting resistor val-
ued at 1.4kΩ. A differential input voltage as high as 10V
will cause only 4.3mA to flow—much less than the
10mA absolute maximum rating. However, in the
MAX4145/MAX4146, R
this condition, the absolute maximum input current rat-
ing might be exceeded if the differential input voltage
exceeds 5.5V (10mA x 150Ω + 10V
510Ω resistors can be placed at IN+ and IN- to limit the
current without degrading performance.
The MAX4144/MAX4145/MAX4146 can be put into low-
power shutdown mode by bringing SHDN high. The
amplifier output is high impedance in this mode; thus
the impedance at OUT is that of the feedback resistors
(1.4kΩ).
The MAX4145/MAX4146 ’s gain is determined by a sin-
gle external resistor, R
+1V/V to +10V/V for the MAX4145 and +10V/V (R
open) to +100V/V for the MAX4146. The gain (in V/V) is
given in the following equations:
IN-
R
R
IN+
G
G
-
+
Input Current =
Setting Gain (MAX4145/MAX4146)
G
G
. The optimal gain range is from
can be as low as 150Ω. Under
(
V
MAX4145
MAX4146
IN+
- V
R
IN-
Shutdown Mode
G
- 10V
F
). In that case,
F
)
G
11
=