Ultra-Low-Noise Variable Gain Low-Frequency Voltage Amplifier
Features
Variable gain 40 to 100 dB, switchable in 20 dB steps
Bipolar input stage, recommended for low impedance sources smaller than 50 Ω
Ultra low input voltage noise: 400 pV/√Hz
AC coupled, single ended
Bandwidth 1.5 Hz - 100 kHz, switchable to 1 kHz
Local and remote control
Applications
Ultra low-noise laboratory amplifier
Pulsed thermal EMF analysis
Chopped thermopiles / bolometers
Industrial sensors
Detector preamplifier
Integrated measurement systems
Block Diagram
Specifications
Test conditions
VS = ±15 V, TA = 25 °C, load impedance = 1 MΩ
Gain
Gain values
40, 60, 80, 100 dB indicated by four LEDs
Gain accuracy
±1 %
Frequency Response
Lower cut-off frequency
1.5 Hz
Upper cut-off frequency
100 kHz, 12 dB/Oct switchable to 1 kHz, 6 dB/Oct.
Time Response Rise/fall time (10 % - 90 %)
3.5 µs (@ BW = 100 kHz) 350 µs (@ BW = 1 kHz)
Input
Input impedance
1 kΩ typ.
Equivalent input voltage noise
Gain setting
Noise
100 dB
400 pV/√Hz
80 dB
420 pV/√Hz
60 dB
800 pV/√Hz
40 dB
6 nV/√Hz
Equivalent input current noise
5,5 pA/√Hz
1/f-noise corner
100 Hz
Input bias current
30 µA
Maximum input DC-offset voltage for linear amplification
±90 mV
Important notice: The input must see a source impedance below 200 Ω.
Output
Output impedance
<100 Ω (terminate with > 100 kΩ load for best performance)
Output voltage range for linear amplification
±10 V (@ > 100 kΩ load)
Output current (max.)
±20 mA
Output overload recovery time
0.5 ms (after 20x overload)
Overload LED
The amplifier features a LED to signalize an overload condition. The Overload LED will turn on if the signal level within the signal path exceeds the linear operating range. In order to ensure the correct operation of the amplifier without signal distortions reduce the gain setting until the Overload LED turns off. The Overload LED may also turn on when the amplifier is operated with open input or with a high source impedance, e. g. external AC coupling. In this case the bias current may cause a considerable input voltage. For proper operation please use a source impedance of less than 100 Ω or switch to a lower gain setting.
Remote Digital Control
Control input voltage range
Low: –0.8 ...+0.8 V High: +1.8 ... +12 V, TTL / CMOS compatible
Control input current
0 mA @ 0 V, 1.5 mA @ +5 V, 4.5 mA @ +12 V
Overload output
Non active: +5 V, max. 1 mA, active: 0.8 V, max. –10 mA
Power Supply
Supply voltage
±15 V (±14.5 V to ±16 V)
Supply current
±55 mA typ. (depends on operating conditions, recommended power supply capability min. ±150 mA)
Case
Weight
0.32 kg (0.7 lbs)
Material
AlMg4.5Mn, nickel-plated
Temperature Range
Storage temperature
–40 °C to +70 °C
Operating temperature
0 °C to +55 °C
Case
Weight
0.32 kg (0.7 lbs)
Material
AlMg4.5Mn, nickel-plated
Temperature Range
Storage temperature
–40 °C to +70 °C
Operating temperature
0 °C to +55 °C
Absolute Maximum Ratings
Power supply voltage
±21 V
Control input voltage
+16 V / –5 V
Signal input voltage
±4 V
Overvoltage at the signal input can severely degrade the noise performance or destroy the amplifier!
Connectors
Input
BNC jack (female)
Output
BNC jack (female)
Power supply
Lemo® series 1S, 3-pin fixed socket (mating plug type: FFA.1S.303.CLAC52)
Pin 1:
+15V
Pin 2:
–15V
Pin 3:
GND
Control port
Sub-D 25-pin, female
Pin 1:
+12 V (stabilized power supply output, max. 60 mA*)
Pin 2:
–12 V (stabilized power supply output, max. 60 mA*)
Pin 3:
AGND (analog ground)
Pin 4:
+5 V (stabilized power supply output, max. 15 mA*)
Pin 5:
digital output: overload
Pin 6:
NC
Pin 7:
NC
Pin 8:
NC
Pin 9:
DGND (ground f. digital control Pin 10 - 25)
Pin 10:
NC
Pin 11:
digital control input: gain, LSB
Pin 12:
digital control input: gain, MSB
Pin 13:
NC
Pin 14:
digital control input: 100 kHz / 1 kHz
Pin 15 - 25:
NC
*check power supply for maximum deliverable current
Remote Control Operation
General
Remote control input bits are opto-isolated and connected by logical OR to local switch setting. For remote control set the corresponding local switch to “0 dB” and “1 kHz” and select the wanted setting via a bit-code at the corresponding digital inputs.
Mixed operation, e.g. local gain setting and remote controlled bandwidth setting, is also possible.
Gain setting
Gain
Pin 11
Pin 12
40 dB
low
low
60 dB
high
low
80 dB
low
high
100 dB
high
high
40 dB
low
low
Bandwidth setting
Bandwidth
Pin 14
1 kHz
low
100 kHz
high
Typical Performance Characteristics
Frequency response
Dimensions
商品属性 [频率] 1.5 Hz - 100 kHz [可变增益] 40 to 100 dB [电压噪声] 400 pV/√Hz