ETC 171J

High Voltage
Differential FET Amplifier
Model 171
High Output Voltage: ±140V
High CMR: 100dB min
Operates With a Wide Range of Power Supplies High
CMV: ± (|VS| - 10V)
High Voltage Compliance Current Source High Voltage
Follower With Gain
High Voltage Integrator
Differential Amp for High CMV Bridge Applications
Reference Power Supply
Model 171 is a high performance FET input op amp designed for
operation over a wide range of supply voltages. This module features an
output range of ±15V to ±140V at l0mA, a minimum CMRR of l00dB
and a high common mode voltage rating of ±(VS - 10V) min. DC offset
is less than ±1mV, and maximum drift of either ±50 or ±l5µV/°C is
available in the J or K versions. Bias current is less than 50pA (171J) or
20pA (171K), doubling per +10°C increase of temperature. The model
171 also features small signal bandwidth of 3MHz for unity gain, fullpower bandwidth of 15kHz, and slew rate of I0V/µs. These operating
characteristics make model 171 an excellent choice for high voltage
buffer applications, followers with gain, off-ground signal
measurements and reference power supplies.
Model 171 offers the flexibility of operating with an extensive range and
combination of power supply voltages. Figure 1 shows a chart of
permissible combinations of supply voltages for the 171. The model 171
maintains its normal operating characteristics when using asymmetrical
power supply configurations.
Excellent power supply rejection of 7µV/V enables model 171 to be
powered by inexpensive, low regulation supplies, without sacrificing
any of the 171's inherent high performance. The supplies also need not
be symmetrical. Any combination of power supply voltages between the
limits of 15 to +300V for the positive side and 15 to -300V for negative
side is acceptable provided the total voltage across the amplifier is
within the range of 30 to 300V.
Model 171's output is completely short circuit protected by the use of a
current limit scheme. This type of protection provides a short circuit
output that is only slightly greater than the rated output current for
normal operation. With this design the module and external circuitry are
protected, internal heat dissipation and the associated high temperature
rise are limited, and added reliability is built in.
Information furnished by Intronics is believed to be accurate and reliable. However, no
responsibility is assumed by Intronics for its use; nor for any infringements of patents or
other rights of third parties which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of Intronics.
Figure 1. Power Supply Voltage Combinations
1400 Providence Highway, Building #2
Norwood, MA 02062
Phone (781) 551-5500
FAX (781) 551-5555