A250F - with internal FET
A250F/NF - with external FET

A250F - with Internal FET

The A250F is a high density version of the Amptek A250 Charge Sensitive Preamplifier.

The A250F includes the input FET (IFN152).

A250F Pin Configuration

Pin 1	Input
Pin 2	FET Drain
Pin 3	Ground and Case
Pin 4	-Vs (-6V Typical)
Pin 5	+Vs (+6V Typical)
Pin 6	Output

 

NOTES

1. The internal feedback resistor R_f = 1 Gohm
2. The internal feedback capacitor C_f = 0.25 pF
   Sensitivity (gain) = 175 mV/MeV (Si)
   4 V/pC
   0.64 µV/electron
   
3. For lower sensitivity applications, C_f can be increased externally
4. The internal 1 kohm resistor from Pin 2 to Pin 5 provides the FET with a drain current of I_DS = 2.75 ma
   I_DS can be increased by adding an external resistor (R < 1 kohm) from Pin 2 to Pin 5

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A250F/NF - with External FET

The A250F/NF is a high density version of the Amptek A250 Charge Sensitive Preamplifier.

The input FET is not included and must be added externally.

A250F/NF Pin Configuration

Pin 1	Feedback Must be connected to Gate of the FET.
Pin 2	Input Must be connected to Drain of the FET.
Pin 3	Ground and Case
Pin 4	-Vs (-6V Typical)
Pin 5	+Vs (+6V Typical)
Pin 6	Output

 

NOTES

1. The internal feedback resistor R_f = 1 Gohm
2. The internal feedback capacitor C_f = 0.25 pF
   Sensitivity (gain) = 175 mV/MeV (Si)
   4 V/pC
   0.64 µV/electron
   
3. For lower sensitivity applications, C_f can be increased externally
4. The external 1 kohm resistor from Pin 2 to Pin 5 provides the FET with a drain current of I_DS = 2.75 ma
   I_DS can be increased by reducing R < 1 kohm

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PC250F Test Board for the A250F or the A250F/NF

Dimensions: 1.75in X 1.75in (4.5cm X 4.5cm)

Mechanical Dimensions

Please refer to the A250 specifications for further information.

A250F Specifications in PDF format

A250F/NF Specifications in PDF format

PC250F Test Board Specifications for the A250F or A250F/NF - 20 k

Revised February 5, 2007