Low noise Pre-amplifier (Photodiodes)

I report the outiline of the low noise pre-amplifier that we will use for the photodiodes.

I have studied this circuit with P-Spice.



In the following i report the P-Spice model used in the simulation:

LT1128:
* Copyright ? Linear Technology Corp. 12/21/06. All rights reserved.

* Pinout: IN+ IN- VCC VEE OUT NULL(Pin1) NULL(Pin8)

.SUBCKT LT1128 3 2 7 4 6

IBIASDEF2 0 2 13E-9

IBIASDEF1 0 3 25E-9

RG1 22 0 372400

CG1 22 0 1E-6

GCM2 0 51 50 4 1E-7

RCMRR 51 0 1E3

GPSRR 0 53 7 4 1.78E-8

RPSRR1 53 0 1E3

RVNOI 41 0 1.58E6

DVNF 42 0 DVNOI

IVNF 0 42 1

GG5 0 25 22 0 6.2832

RG5 25 0 0.159155

CG5 25 0 1.5E-6

IDUM1 41 0 0

DVNFX 43 0 DVNOIX

IVNFX 0 43 1

RINX 21 0 0.05675

GG1 0 22 VALUE={9*TANH(V(21))}

MOUT1 77 29 6 6 NOUT

MOUT2 44 29 6 6 POUT

DVL1 23 22 DVLIM

DVL2 23 0 DVLIM

EICM 50 0 VALUE={(V(3)+V(2))/2}

CCMRR 50 52 2.5E-11

RCMRR2 52 51 2k

GIN2 0 21 VALUE={V(101,102)+V(41)+V(42,43)+V(51)+V(53)+1E-5}

GB 0 29 VALUE={3.14*(V(7)+V(4))}

GINOI1 3 0 41 0 1.17E-3

GINOI2 2 0 41 0 1.17E-3

DIN5 2 3 DIN

DIN6 3 2 DIN

GIN1 102 101 3 2 0.035

IIN1 101 4 9E-4

IIN2 102 4 9E-4

RIN1 1 101 3E3

RIN2 8 102 3E3

RIN3 7 1 130

RIN4 7 8 130

GG3 0 27 25 0 0.1

RG3 28 27 10

RG4 0 28 250

LG1 28 0 5E-7

GLIM1 7 77 VALUE={MIN(0.03,(V(7,77)-2))}

GLIM2 44 4 VALUE={MIN(0.03,(V(44,4)-2))}

CIN1 4 3 5E-12

CIN2 2 4 5E-12

GG4 0 29 27 0 6.2832

RG6 29 0 0.159155

CG3 29 0 1.0E-8

ITYP 7 4 5.6E-3

.MODEL NOUT NMOS(KF=0 KP=5 VTO=-1m RD=0)

.MODEL POUT PMOS(KF=0 KP=5 VTO=1m RD=0)

.MODEL DIN D(KF=0 RS=0 IS=1E-16)

.MODEL DVLIM D(BV=18 IS=1E-10 KF=0 RS=0)

.MODEL DVNOIX D(KF=0 RS=0)

.MODEL DVNOI D(RS=0 KF=2E-10)

.ENDS LT1128


IF3602
* ee NJF model

* created using Model Editor release 9.2 on 06/29/08 at 13:27

* The Model Editor is a PSpice product.

.MODEL ee NJF

+ BETA=700E-3

+ LAMBDA=1.0000E-4

+ RD=100

+ RS=100

+ IS=0.5E-9

+ CGD=200.00E-12

+ CGS=100.00E-12

+ KF=1.0000E-18

+ VTO=-3

MoreOVer I report the simulation of the low noise pre-amplifier for the photodiodes.

I think that we can use the circuit in the following condition:

1) G=100 (R24=5 e R2=500 )
2) G=1000 (R24=10 e R2=10k)

In the first and second cases we can choice the better bandwidth:

1)
R1=variable, C1=10n


C1=variable, R1=500



We can use the following values: R1=1k e C1=10n (with G=100)


2)
In the second case, instead, we have: R1=100, C1=1n (with G=1000)



I will try to study the noise of this circuit by mean of SimuLink of MAtLab or also, with but i don't know, P-Spice.