Datasheet

DDPCA-300
Variable Gain
Sub Femto Ampere Current AmplifierFeatures

0.4 fA peak-to-peak noise
Very high dynamic range: sub-fA to 1 mA (> 240 dB)
413
Transimpedance (gain) switchable from 1 x 10 to 1 x 10 V/A
Bandwidth up to 400 Hz, rise time down to 0.8 ms - independent ofsource capacitance (up to 10 nF)
Adjustable bias voltage on input relative to ground
Compact housing for use close to the signal source
Local and remote control
Easy to use:
Convert your standard digital voltmeter or DAQ board to a high-enddigital sub femto amperemeter

Applications

Photodetector amplifier
I/V characterization of small MOS structures
DC measurements of ultra-low currents
Ionization detectors, mass spectrometry, quantum and biotech experimentscharacterization of high impedance nanomaterials
Spectroscopy
High resistance measurements

Block Diagram

SOPHISTICATED TOOLS FOR SIGNAL RECOVERY
DE-DDPCA-300_R8/MvB,JM/04MAY2016

Page 1 of 9

Datasheet

DDPCA-300
Variable Gain
Sub Femto Ampere Current Amplifier

Specifications

Test conditions

VS = ±15 V, TA = 25 °C, relative humidity < 50 %load impedance = 1 MΩ
warm-up 20 minutes (min. 10 minutes recommended)

GainTransimpedanceGain accuracy
Gain drift

1 x 10 ... 1 x 10 V/A (load ≥ 100 kΩ)±1 %see table below

Frequency Response

Lower cut-off frequency
Upper cut-off frequency
Adjustable low pass filter

DCup to 400 Hz (see table below)
switchable to 3 settings (full bandwidth, 0.7 Hz and 0.1 Hz)

413

Upper cut-off
Full BW (see table below)
0.7 Hz0.1 HzRise time
Fast (see table below)
0.5 s
5s

Setting the low pass filter to full bandwidth is recommended
for high measurement speed. By setting the low pass filter to0.7 Hz or 0.1 Hz the peak-to-peak noise performance canbe improved but the signal settling time will be longer.
Input

Equ. input noise current

Input bias current
Input bias current drift
Max. input current (full scale)
Input offset compensation
Performance Depending
on Gain Setting

gain setting dependent, see table below
minimum input noise is 0.4 fA peak-peak (at gain setting
1213
10 or 10 V/A with low pass filter switched to 0.1 Hz)
20 fA typ. / 30 fA max.
factor 2 / 10 °C
see table below (value for linear amplification)
adjustable by offset potentiometer, ±100 fA

Gain setting (V/A)

104105106107108

Upper cut-off frequency (–3 dB)*
Rise/fall time (10 % - 90 %)*Integrated input noise current (peak-peak)*Spectral input noise current density (/√Hz)
Measured atGain drift (/°C)
Max. input current (± full scale)
DC input impedance (// 5 pF)

400 Hz0.8 ms
7 nA
45 pA
10 Hz0.01 %
1 mA
<1Ω

Gain setting (continued) (V/A)

109400 Hz
0.8 ms
7 nA45 pA
10 Hz
0.01 %
0.1 mA
<1Ω
1010400 Hz
0.8 ms70 pA0.45 pA
10 Hz
0.01 %10 µA<1Ω
1011400 Hz
0.8 ms70 pA0.45 pA
10 Hz
0.01 %1 µA<1Ω
1012150 Hz
2.3 ms1.2 pA
15 fA
10 Hz
0.01 %
0.1 µA< 100 Ω
1013

Upper cut-off frequency (–3 dB)*
Rise/fall time (10 % - 90 %)*Integrated input noise current (peak-peak)*Spectral input noise current density (/√Hz)
Measured atGain drift (/°C)
Max. input current (± full scale)
DC input impedance (// 5 pF)

150 Hz 20 Hz
20 Hz
1 Hz
2.3 ms 17 ms 17 ms 350 ms
1.2 pA 50 fA
50 fA
2 fA
15 fA
1.3 fA
1.3 fA
0.2 fA
10 Hz
1 Hz
1 Hz
0.4 Hz0.01 % 0.03 % 0.03 % 0.03 %
10 nA
1 nA
0.1 nA 10 pA< 100 Ω < 10 kΩ < 10 kΩ < 1 MΩ

1 Hz
350 ms
2 fA
0.2 fA
0.4 Hz0.03 %1 pA< 1 MΩ* The values for upper cut-off frequency, rise/fall time and integrated input noise current stated inthe table above are achieved with the low pass filter set to “Full BW / Fast” (full bandwidth/fast risetime). Lower peak-to-peak noise values can be achieved by setting the low pass filter to 0.7 Hz or
0.1 Hz. In that case the bandwidth will be lower and the signal rise / fall time will be longer though.

SOPHISTICATED TOOLS FOR SIGNAL RECOVERYPage 2Datasheet

DDPCA-300
Variable Gain
Sub Femto Ampere Current Amplifier

Specifications (continued)
OutputOutput voltageOutput impedance
Max. output current±10 V (load ≥ 100 kΩ)
50 Ω (terminate with ≥ 100 kΩ load for best performance)±30 mA

Adjustable Bias Voltage

GeneralAn adjustable bias voltage is provided for directly biasing thedevice under test DUT (e.g. photodiode, high resistancesemiconductor component). The bias voltage is connected tothe inner conductor of the BNC input socket; the BNC-shield isalways connected to analog ground. The bias voltage can beset either locally at the amplifier or through the remoteinterface. For measurements not requiring a bias voltage it canbe fully disabled.

Bias voltage range
Bias current±10 V at inner conductor of BNC input socket
max. ±10 mA

Local Bias Adjustment

Bias switch setting
Bias adjustment

set bias switch to position “Int.”
adjust bias voltage by bias potentiometer

Remote Bias Adjustment

Bias switch setting
Bias adjustment

set bias switch to position “Ext.”
adjust bias by analog control voltage fed to pin 8 of Sub-D
connector (referred to AGND pin 3)
Input impedance of control pin 8 200 kΩ
Bias control voltage range±10 V at pin 8 (referred to AGND pin 3)
Bias control polarity
inverting
Example:feeding a control voltage of +2 V to pin 8 of the Sub-Dconnector leads to –2 V bias voltage at the innerconductor of the BNC input socket referred to BNC shield(analog ground, AGND)

Bias Deactivation

Bias switch setting

set bias switch to position “Off”

Bias Monitor Output

Range± 10 V, shows the adjusted bias voltage at theBNC input (inner conductor referred to AGND pin 3)
pin 7 of Sub-D connector (referred to AGND pin 3)
50 Ω (terminate with ≥ 100 kΩ load for best performance)

Connector
Output impedanceOverload Indication

LEDOverload output

lights when overload is detected
non active: <0.4 V @ 0 … –1 mA,active:
typ. 5 … 5.1 V @ 0 … 2 mA

Digital Control

Control input voltage range
Control input current

LOW bit: –0.8 ...+1.2 V, HIGH bit: +2.3 ... +12 V
0 mA @ 0 V; 1.5 mA @ +5 V; 4.5 mA @ +12 V

Auxiliary Power Output

Voltage±12 VDC, stabilized, max. ±20 mA (at Sub-D, may be used
for supplying external devices up to ±20 mA)Power Supply

Supply voltage
Supply current±15 V+70 mA / –15 mA typ. (depends on operating conditions,recommended power supply capability minimum ±150 mA)

Case

WeightMaterial

320 g (0.74 lb.)
AlMg4.5Mn, nickel-plated

Temperature Range

Storage Temperature
Operating Temperature–40 ... +85 °C
0 ... +50 °C

SOPHISTICATED TOOLS FOR SIGNAL RECOVERYPage 3

Datasheet

DDPCA-300
Variable Gain
Sub Femto Ampere Current Amplifier

Absolute Maximum Ratings

Signal input voltage
Electrostatic discharge
Digital control input voltage
Bias control input voltage
Power supply voltage±15 V relative to bias
±2 kV human body model (HBM)–5 V / +16 V±12 V±20 VConnectors

Input

BNC, isolated, jack (female)

Output

BNC, jack (female)

Bias voltage output

center pin of BNC input socket

Power supply

Lemo series 1S, 3-pin fixed socket(mating plug type: FFA.1S.303.CLAC52)®

Pin 1:Pin 2:Pin 3:+15V
–15V
GND

PIN 2–Vs

PIN 1+Vs

PIN 3
GND

Control Port

Sub-D 25-pin, female, qual. class 2
Pin 1:+12V (stabilized power supply output)
Pin 2:–12V (stabilized power supply output)
Pin 3:
AGND (analog ground)Pin 4:NC
Pin 5:
overload output (referred to AGND pin 3)
Pin 6:
signal output(connected to BNC output connector)
Pin 7:
bias voltage monitor output(referred to AGND pin 3)
Pin 8:
bias control voltage input(referred to AGND pin 3)
Pin 9:
DGND (ground for digital control pins 10 - 13)
Pin 10:digital control input: gain, LSB
Pin 11:
digital control input: gain
Pin 12:
digital control input: gain
Pin 13:
digital control input: gain, MSB
Pin 14 - 25: NC

SOPHISTICATED TOOLS FOR SIGNAL RECOVERY
Page 4

Datasheet

DDPCA-300
Variable Gain
Sub Femto Ampere Current Amplifier

Remote Control Operation

GeneralRemote control input bits are opto-isolated. For remotecontrol operation set the rotary gain switch to the“Remote” position and select the desired gain setting via abit code at the digital inputs.
Switch settings “0.1 Hz / Full BW / 0.7 Hz” and“Bias Ext. / Off / Int.” are not remote controllable.

Gain Setting

Gain (V/A)

Pin 13MSB

Pin 12

Pin 11

Pin 10LSB4105106107108109101010111012101310

LOW
LOW
LOW
LOW
LOW
LOW
LOW
LOW
HIGH
HIGH

LOW
LOW
LOW
LOW
HIGH
HIGH
HIGH
HIGH
LOW
LOW

LOW
LOW
HIGH
HIGH
LOW
LOW
HIGH
HIGH
LOW
LOW

LOW
HIGH
LOW
HIGH
LOW
HIGH
LOW
HIGH
LOW
HIGH

SOPHISTICATED TOOLS FOR SIGNAL RECOVERY
Page 5

Datasheet

DDPCA-300
Variable Gain
Sub Femto Ampere Current Amplifier

Typical Performance
Characteristics

Long term drift

5 fA

Equivalent Input Current

4 fA
3 fA
2 fA
1 fA
0 fA
-1 fA
-2 fA
-3 fA
-4 fA
-5 fA
0h

1h2h

3h4h6h7h

80 s

100 s

120 s

Time
Short term drift

Equivalent Input Current

2 fA

1 fA

0 fA

-1 fA

-2 fA0s

20 s

40 s

60 s
Time

12

Both drift curves were recorded with shielded input in the gain setting 10 V/A, filter setting
0.1 Hz (20 minutes warm-up before measurement).

SOPHISTICATED TOOLS FOR SIGNAL RECOVERY
Page 6Datasheet

DDPCA-300
Variable Gain
Sub Femto Ampere Current Amplifier

Typical Performance
Characteristics

10 fA square wave

2 fA step curve

12Both curves were recorded in the gain setting 10 V/A, filter setting 0.7 Hz, no externalaveraging (20 minutes warm-up before measurement).

SOPHISTICATED TOOLS FOR SIGNAL RECOVERY
Page 7

Datasheet

DDPCA-300
Variable Gain
Sub Femto Ampere Current Amplifier

Typical Performance
Characteristics

0.5 fA step curve, no averaging

0.5 fA step curve, 4 times external averaging

13Both curves were recorded in the gain setting 10 V/A, filter setting 0.1 Hz (20 minuteswarm-up before measurement).

SOPHISTICATED TOOLS FOR SIGNAL RECOVERY
Page 8

DatasheetDDPCA-300
Variable Gain
Sub Femto Ampere Current Amplifier

Dimensions

157150
15137

4451

I/V

all measures in mm unless otherwise noted

FEMTO Messtechnik GmbHKlosterstr. 6410179 Berlin · Germany
Phone: +49 30 280 4711-0
Fax: +49 30 280 4711-11
Email: info@femto.de
www.femto.de

44.2

28.5

15.4

15

ø 3.2

DZ-DDPCA-300_R6

Specifications are subject to change without notice. Information provided herein is believed to be accurate andreliable. However, no responsibility is assumed by FEMTO Messtechnik GmbH for its use, nor for any infringementof patents or other rights of third parties which may result from its use. No license is granted by implication orotherwise under any patent or patent rights of FEMTO Messtechnik GmbH. Product names mentioned may also be
trademarks used here for identification purposes only.
© by FEMTO Messtechnik GmbH · Printed in Germany

SOPHISTICATED TOOLS FOR SIGNAL RECOVERYPage 9