Hi,

We are planning to use PGA309 in an industrial sensor application. We have gone through the calibration process for the evaluation module, but have seen very little information about what actually happens during calibration. What are the steps need to be followed to calibrate a sensor when not using the EVM? Is there any documentation you can refer us to? Is it possible to get the source code for the software so that we can better understand the process, and modify it for our own purposes? There is source code on TI website, but that does not seem to be ASCII.

Any help is much appreciated.

I want to use the application of opa 365 to make a driver for laser diode .  and when i saw a nice laser diode driver design, coming from Texas Instruments's  SBEA001 (the "Laser Diode Driver 1") by Neil P. Albaugh ,  i thought it is a good design for laser driver .  but i can not find the exact datasheet for FTZ869 . i think it is wrong in the design and that transistor should be FZT869 . Am i right ?

Hello TI,

I intend to use xtr110 for i/p = 1-5 V  and o/p = 4-20mA and I have developed a prototype for the same.

The connections are as shown in fig. (as per datasheet)

pin 5 is used as i/p while pin 3 & 4 are shorted to common.

While testing with this configuration I got 22V at pin 14 which as per my knowledge is not desirable.

Voltage at pin 11 is 0V which suggests that xtr110 is not turned on.

After that I disconnected pin12 and 15 from pin 3 and left shorted 12 and 15 open, but no luck.

I have checked all the connections and they are properly done.

I tried this with 4 xtr110 ic's but it gives same result.

I'm bit confused as I couldn't find exact configuration of pin 15 and 12, please guide me where I'm making mistake.

Regards

Shrikant L

Hi

For LM2904, I 've seen 0.7mA(TYP) at V0=2.5V with no load as shown in below.

If you have a current spec with below condition would you share with me?

Vo=0V, No load

Hope to see prompt answer.

Thanks in advance.

Hello,

I plan to use an INA826 at unity gain, with small (<20 Ohm) series resistors on its inputs (this resistor value cannot be increased for a number of reasons). It is critical to know at least one of the following overload parameters:

1. The maximum input current (at inverting or non-inverting input) of the INA826 at 25^oC, when a +/-15V input overvoltage occurs and the device is powered off. That is, when both supply pins are at 0V.

2. The same parameter at +85^oC.

The problem with the datasheet (figure 17) page is that it provides only typical values at non-zero supply voltage and room temperature. I could extrapolate the temperature coefficient of the threshold voltage of the internal FET limiter. I could also made some assumptions for the power-off condition. But the spread of the threshold voltage (from part to part) is still unknown and quite unpredictable. At least I could make some fair assumptions if I knew that spread (say, within 98% confidence value).

Thank you in advance

Hi all..

I need to extract the signal of a particular frequency.. i have tried with MFB, sallen key and several op amp active band pass filters. Any other design resource or ideas to get this job done..

The frequency was below 200hz only.. low frequency...

please....

Thanks..

Sandeep

Hi, I'm trying to build a strain gauge circuit using an instrumental amplification IC (INA126PA), however the voltage outputs seem incorrect. Given voltage inputs of V+ = 0.501 mV,  V- = 0.500mV  and a gain of 5000 (Gain resistor = 18 ohms) I would expect to see about 5V at the output of the chip. Instead I get a value of 0.5V.

Varying the gain resistance or even removing the resistor altogether only has a very small effect on the output (Vo increases by about 20mV), which is what has me really confused.

I've included a circuit diagram below. The circuit is currently built on a breadboard. The input voltages are supplied by a USB NI-6009 DAQ and the input is recorded by this too. I have tried different positions on the board in case of poor connections and I have tried buying another chip in case it was faulty.

I feel like I must be missing something obvious. Can anyone identify a problem?

Regards,

Tim

Hello

What is the reason for the via keep out area for the INA826? 

Also, to confirm, can traces be in the via keep out area?

Thank you

Keir

I have an issue using the PSPICE model for OPA320

following error message:

**** 07/16/14 13:21:54 ***** PSpice 16.6.0 (October 2012) ***** ID# 0 ********

** Profile: "SCHEMATIC1-ac-sweep" [ U:\docs\Cadence\Workspace\analog_opto_sim-pspicefiles\schematic1\ac-sweep.sim ]

**** CIRCUIT DESCRIPTION

******************************************************************************

** Creating circuit file "ac-sweep.cir"
** WARNING: THIS AUTOMATICALLY GENERATED FILE MAY BE OVERWRITTEN BY SUBSEQUENT SIMULATIONS

*Libraries:
* Profile Libraries :
* Local Libraries :
.LIB "U:/docs/SUM project/OPA320_PSPICE_AIO/opa320.lib"
.LIB "V:/KKE/RD/UDV/ORCADWIN/Library/V9_2_3_KK/KKLIB.lib"
* From [PSPICE NETLIST] section of U:\docs\Cadence\Workspace\\cdssetup\OrCAD_PSpice/16.6.0/PSpice.ini file:
.lib "nom.lib"

*Analysis directives:
.AC DEC 10 1khz 10meghz
.OPTIONS ADVCONV
.PROBE64 V(alias(*)) I(alias(*)) W(alias(*)) D(alias(*)) NOISE(alias(*))
.INC "..\SCHEMATIC1.net"

**** INCLUDING SCHEMATIC1.net ****
* source ANALOG_OPTO_SIM
.EXTERNAL OUTPUT LV_out
C_C2 N18571 N15494 50nF TC=0,0
R_R3 N152200 N15244 160 TC=0,0
C_C3 N15184 0 100n TC=0,0
R_R6 N15324 0 68k TC=0,0
R_R1 N15414 N15494 1k TC=0,0
R_R5 0 N15184 1k TC=0,0
R_R2 N15414 IN_P_REG 100k TC=0,0
X_U3 0 N15244 5V_REF N15324 N15332 5V_REF_ISO HCNR200
R_R7 N15332 0 68k TC=0,0
R_R4 5V_REF N15184 1k TC=0,0
V_V1 5V_REF 0 5
V_V2 5V_REF_ISO 0 5
V_V3 N18571 0 DC 0Vdc AC 0.01Vac
V_V4 IN_FEEDBACK N15324 DC 0Vdc AC 1Vac
X_U4 N15184 N15414 5V_REF 0 IN_P_REG OPA320
X_U5 IN_P_REG IN_FEEDBACK 5V_REF 0 N152200 OPA320
X_U6 N15332 LV_OUT 5V_REF_ISO 0 LV_OUT OPA320

**** RESUMING ac-sweep.cir ****
.END

WARNING(ORPSIM-15223): Library file V:\KKE\RD\UDV\ORCADWIN\Library\V9_2_3_KK\KKLIB.lib has changed since index file KKLIB.ind was created.

WARNING(ORPSIM-15227): The timestamp changed from Wed Jul 16 10:55:04 2014 to Wed Jul 16 13:21:23 2014.

INFO(ORPSIM-15422): Making new index file KKLIB.ind for library file KKLIB.lib.

Index has 33 entries from 1 file(s).

ERROR(ORPSIM-15142): Node N15494 is floating

ERROR(ORPSIM-15142): Node N15414 is floating

ERROR(ORPSIM-15142): Node IN_P_REG is floating

ERROR(ORPSIM-15142): Node X_U4.INPUT_OUTN is floating

ERROR(ORPSIM-15142): Node X_U4.INPUTN_CMRR is floating

ERROR(ORPSIM-15142): Node X_U4.INPUTN_ICMR is floating

ERROR(ORPSIM-15142): Node X_U5.INPUTP_CMRR is floating

ERROR(ORPSIM-15142): Node X_U5.INPUTP_ICMR is floating

ERROR(ORPSIM-15142): Node X_U5.INPUT_OUTP is floating

ERROR(ORPSIM-15142): Node LV_OUT is floating

ERROR(ORPSIM-15142): Node X_U6.INPUT_OUTN is floating

ERROR(ORPSIM-15142): Node X_U6.INPUTN_CMRR is floating

ERROR(ORPSIM-15142): Node X_U6.INPUTN_ICMR is floating

ERROR(ORPSIM-15142): Node X_U5.INPUT_VOS is floating

my regional orcad support center told me that the model is not constructed correct. is it true

model info:

* OPA320
*****************************************************************************
* (C) Copyright 2012 Texas Instruments Incorporated. All rights reserved.
*****************************************************************************
** This model is designed as an aid for customers of Texas Instruments.
** TI and its licensors and suppliers make no warranties, either expressed
** or implied, with respect to this model, including the warranties of
** merchantability or fitness for a particular purpose. The model is
** provided solely on an "as is" basis. The entire risk as to its quality
** and performance is with the customer.
*****************************************************************************
*
** Released by: WEBENCH(R) Design Center, Texas Instruments Inc.
* Part: OPA320
* Date: 08/27/13
* Model Type: All In One
* Simulator: Pspice
* Simulator Version: Pspice 16.2.0.p001
* EVM Order Number: N/A
* EVM Users Guide: N/A
* Datasheet: SBOS513D - AUGUST 2011 - Revised NOVEMBER 2011
*
* Model Version: 2.0
*
*****************************************************************************
*
* Updates:
*
* Version 1.0 : Release to Web
* Version 2.0 : Correct GOS for single-supply operation
*
*****************************************************************************
* Notes:
* The model meets the following datasheet specs for 5.5V (+-2.75V) operation
* at a temperature of 27C with a load resistance of 10kohms:
* VOS, IIB, Input common-mode Voltage Range, CMRR, noise, Input Capacitance,
* Open-loop voltage gain, GBW, Slew Rate, Output Voltage Swing,
* Open-loop Output Resistance, Quiescent Current
* Enable and Disable Time,
*
* The model meets the following specs over the published operating temperature
* range:
* IIB
*
* The model does not meet the following datasheet specs:
* phase margin, AOL at 2k load resistance, power-on time,
* Short circuit output current is about half the published value.
*
* The settling time for the macromodel is less than the published device specs.
*****************************************************************************
*$
.SUBCKT OPA320 INP INN VCC VEE OUT
C_C4 INN INP 4p TC=0,0
E_E2 N61051 0 VEE 0 1
X_U22 INPUT_OUTP INPUT_VOS VNSE_OPA320
X_U28 INPUTP_GBW INPUTN_GBW VCC VEE INPUTP_ICMR INPUTN_ICMR EN GNDF ICMR_OPA320
X_U12 INPUT_TF INPUT_VCLAMP VCC VEE EN GNDF TF_OPA320
X_U19 OUT_CNTRL SHDN VCC VEE GNDF SHDN_NOT_OPA320
E_E5 INPUTP_CMRR INPUTP_ICMR OUT_CMRR GNDF 0.5
X_U29 VCC VEE INPUT_VCLAMP INPUT_VIMON VIMON GNDF VCLAMP_W_SENSE_OPA320
R_R10 GNDF EN 10k TC=0,0
X_U31 INPUT_VIMON INPUT_ZOUT VIMON GNDF AMETER_OPA320
X_U18 INPUTP_ICMR GNDF VCC VEE VICM GNDF IIBP_OPA320
V_V4 N278677 GNDF 0.69Vdc
X_U5 VICM INP INN GNDF VICM_OPA320
X_U30 INPUTP_CMRR INPUT_VOS VICM VCC VEE GNDF VOS_OPA320
G_G1 OUT_CMRR GNDF VICM GNDF -7e-6
R_R6 OUT_CNTRL N278435 100 TC=0,0
GOS INPUT_ZOUT OUT VALUE = {(1/90)*(1e-8+V(EN,GNDF))*V(INPUT_ZOUT,OUT)}
X_U13 INPUTP_GBW INPUTN_GBW INPUT_TF EN GNDF GBW_SLEW_OPA320
X_U26 VCC VEE INPUT_OUTN INPUTN_CMRR GNDF PSRR_OPA320
R_R1 N61125 N61045 1e6 TC=0,0
X_U20 VCC VEE EN VIMON GNDF IQ_OPA320
D_D1 IN_COMP N278435 Dbreak
X_U17 GNDF INPUTN_ICMR VCC VEE VICM GNDF IIBN_OPA320
R_R4 INN INPUT_OUTN 1 TC=0,0
R_R2 N61051 N61125 1e6 TC=0,0
R_R9 OUT_CNTRL IN_COMP 1k TC=0,0
C_C1 0 N61125 1m TC=0,0
C_C6 GNDF IN_COMP 18n TC=0,0
R_R3 INP INPUT_OUTP 1 TC=0,0
X_U23 INPUT_OUTN INPUT_VOS FEMT_OPA320
E_E3 GNDF 0 N61125 0 1
R_R5 N114739 GNDF 1 TC=0,0
C_C2 INN GNDF 2p TC=0,0
X_U2 EN IN_COMP N278677 GNDF COMPARATOR_OPA320
E_E1 N61045 0 VCC 0 1
L_L1 OUT_CMRR N114739 8uH
C_C3 GNDF INP 2p TC=0,0
E_E4 INPUTN_CMRR INPUTN_ICMR OUT_CMRR GNDF -0.5
V_INT SHDN GNDF 2
.model Dbreak D N=0.001 RS=0.001 T_ABS=27
.ENDS OPA320
*$
**
.SUBCKT VNSE_OPA320 1 2
.PARAM NLF = 5
.PARAM FLW = 1000
.PARAM NVR = 7
.PARAM GLF={PWR(FLW,0.25)*NLF/1164}
.PARAM RNV={1.184*PWR(NVR,2)}
.MODEL DVN D KF={PWR(FLW,0.5)/1E11} IS=1.0E-16
I1 0 7 10E-3
I2 0 8 10E-3
D1 7 0 DVN
D2 8 0 DVN
E1 3 6 7 8 {GLF}
R1 3 0 1E9
R2 3 0 1E9
R3 3 6 1E9
E2 6 4 5 0 10
R4 5 0 {RNV}
R5 5 0 {RNV}
R6 3 4 1E9
R7 4 0 1E9
E3 1 2 3 4 1
C1 1 0 1E-15
C2 2 0 1E-15
C3 1 2 1E-15
.ENDS
*$
.SUBCKT ICMR_OPA320 VOP VOM VDD VSS VIP VIM SHDN GNDF
.PARAM VMAX = -0.12
.PARAM VMIN = -0.12
ECLAMPP VOP GNDF VALUE = {LIMIT(V(VIP,GNDF),V(VDD,GNDF) - VMAX, V(VSS,GNDF) + VMIN)}
ECLAMPM VOM GNDF VALUE = {LIMIT(V(VIM,GNDF),V(VDD,GNDF) - VMAX, V(VSS,GNDF) + VMIN)}
.ENDS
*$
.SUBCKT TF_OPA320 VI VO VCC VEE SHDN GNDF
.PARAM fp1 = 45e6
*.PARAM fp1 = 20e6
.PARAM fp2 = 10G
.PARAM fp3 = 10G
.PARAM fp4 = 10G
.PARAM Gm = 1M
.PARAM Ro = {1/Gm}
.PARAM PI = 3.141592
.PARAM gL = 1M
Gp1 GNDF VO VI GNDF {Gm}
Rp1 VO GNDF {Ro}
Cp1 VO GNDF {1/(2*PI*Ro*fp1)} IC = 0
.ENDS
*$
.SUBCKT SHDN_NOT_OPA320 OUT_CNTRL IN VCC VEE GNDF
.PARAM VIHparam = 0.7
.PARAM VILparam = 0.3
.PARAM VIMIDparam = 0.5
.PARAM VSmax = 5.5
.PARAM IIBmin = 0.04u
.PARAM IIBmax = 0.13u
.PARAM VCCnom = 5
.PARAM VD = 0.3
.PARAM VMAX = 6
ETEST TEST 0 VALUE = {V(IN,GNDF)}
EN1 N1 GNDF VALUE = {IF(V(IN) < V(GNDF),0,1)}
EN2 N2 GNDF VALUE = {IF(V(IN) >= V(GNDF),1,0)}
EN3 N3 GNDF VALUE = {IF(V(IN) > V(VCC)+VD,0,1)}
EN4 N4 GNDF VALUE = {IF(V(IN) < V(VEE)-VD,0,1)}
EN6 N6 GNDF VALUE = {IF((V(VCC)-V(VEE)) > VMAX,0,1)}
EOUT OUT_CNTRL GNDF VALUE = {V(N1,GNDF)*V(N2,GNDF)*V(N3,GNDF)*V(N4,GNDF)*V(N6,GNDF)}
EN5 N5 GNDF VALUE = {(V(IN,VEE)/55e6) + IIBmin}
GIB_IN IN GNDF VALUE = {V(N5,GNDF)*V(N3,GNDF)*V(N4,GNDF)}
.ENDS
*$
.SUBCKT VCLAMP_W_SENSE_OPA320 VDD VSS VI VO VIMON GNDF
.PARAM SCALEP = 1
.PARAM SCALEN = 1
.PARAM ISC = 0.065
.PARAM ROS = 90
EHRPOS HRPOS GNDF VALUE = {MIN(V(VIMON,GNDF)*69.2,ISC*ROS-V(VDD,GNDF))}
EHRNEG HRNEG GNDF VALUE = {MAX(V(VIMON,GNDF)*69.2,-ISC*ROS-V(VSS,GNDF))}
EPCLIP VDD_CLP GNDF VALUE = {V(VDD,GNDF) + V(HRPOS,GNDF)}
ENCLIP VSS_CLP GNDF VALUE = {V(VSS,GNDF) + V(HRNEG,GNDF)}
ECLAMP VO GNDF VALUE = {LIMIT(V(VI,GNDF), V(VDD_CLP,GNDF), V(VSS_CLP,GNDF))}
.ENDS
*$
.SUBCKT AMETER_OPA320 VI VO VIMON GNDF
.PARAM GAIN = 1
VSENSE VI VO DC = 0
EMETER VIMON GNDF VALUE = {I(VSENSE)*GAIN}
.ENDS
*$
.SUBCKT IIBP_OPA320 OUT IN VCC VEE INP GNDF
.PARAM SCALE = 1p
.PARAM IIBtyp = 0.1
.PARAM m1t = 0
.PARAM m2t = 2
.PARAM m3t = 8
.PARAM m4t = 52
.PARAM m1v = -1
.PARAM m2v = 0.001
.PARAM m3v = -10
.PARAM b1v = -0.9
.PARAM b3v = 23
EIIBt NIIBt 0 VALUE = {MAX(1,PWR(2,(TEMP-27)/10))}
Ein Nin 0 VALUE = {V(INP,GNDF)}
E1v N1v 0 VALUE = {m1v*V(Nin) + b1v}
E2v N2v 0 VALUE = {m2v*V(Nin) + IIBtyp}
E3v N3v 0 VALUE = {m3v*V(Nin) + b3v}
E4v N4v 0 VALUE = {MIN(MAX(V(N1v),V(N2v)),V(N3v))}
EIIBv NIIBv 0 VALUE = {V(N4v)/1}
GOUT OUT IN VALUE = {SCALE*(V(NIIBt)*V(NIIBv))}
.ENDS
*$
.SUBCKT VICM_OPA320 OUT INP INN GNDF
EOUT OUT GNDF VALUE = {0.5*(V(INP,GNDF) + V(INN,GNDF))}
.ENDS
*$
.SUBCKT VOS_OPA320 OUT IN VICM VCC VEE GNDF
.PARAM SCALE = 1e-6
.PARAM DRIFT = 1.5
.PARAM VICM_SHIFT = 9.1
.PARAM VCC_SHIFT = 5
.PARAM VOS_TYP = -40
EDRIFT NDRIFT 0 VALUE = {DRIFT*(TEMP - 27)}
ESHIFT NSHIFT 0 VALUE = {VICM_SHIFT*V(VICM,GNDF)}
EVCC NVCC 0 VALUE = {V(VCC,VEE)}
EVCCSHIFT NVCCSHIFT 0 VALUE = {VCC_SHIFT*(V(NVCC) - 5.5)}
EVOS OUT IN VALUE = {SCALE*(VOS_TYP + V(NDRIFT) + V(NSHIFT) + V(NVCCSHIFT))}
.ENDS
*$
.SUBCKT GBW_SLEW_OPA320 VIP VIM VO SHDN GNDF
.PARAM Aol = 130
.PARAM GBW = 20e6
.PARAM SRP = 10e6
.PARAM SRN = 10e6
.PARAM IT = 0.001
.PARAM PI = 3.141592
.PARAM IP = {IT*MAX(1,SRP/SRN)}
.PARAM IN = {IT*MIN(-1,-SRN/SRP)}
.PARAM CC = {IT*MAX(1/SRP,1/SRN)}
.PARAM FP = {GBW/PWR(10,AOL/20)}
.PARAM RC = {1/(2*PI*CC*FP)}
.PARAM GC = {PWR(10,AOL/20)/RC}
G1p GNDF OUTG1p VALUE = {MAX(MIN(GC*V(SHDN,GNDF)*V(VIP,VIM),IP),IN)}
G1n OUTG1n GNDF VALUE = {MAX(MIN(GC*V(SHDN,GNDF)*V(VIP,VIM),IP),IN)}
G1OUT GNDF VO VALUE = {V(SHDN,GNDF)*V(OUTG1p,OUTG1n)}
RG1p OUTG1p GNDF {0.5*RC}
Cg1dp OUTG1p GNDF {2*CC} IC=0
RG1n OUTG1n GNDF {0.5*RC}
Cg1dn OUTG1n GNDF {2*CC} IC=0
ROUT VO GNDF 1
.ENDS
*$
.SUBCKT PSRR_OPA320 VDD VSS VI VO GNDF
.PARAM PSRR = 140
.PARAM fpsrr = 1
.PARAM PI = 3.141592
.PARAM RPSRR = 1
.PARAM GPSRR = {PWR(10,-PSRR/20)/RPSRR}
.PARAM LPSRR = {RPSRR/(2*PI*fpsrr)}
G1 GNDF 1 VDD VSS {GPSRR}
R1 1 2 {RPSRR}
L1 2 GNDF {LPSRR}
E1 VO VI 1 GNDF 1
C2 VDD VSS 10P
.ENDS
*$
.SUBCKT IQ_OPA320 VCC VEE SHDN VIMON GNDF
.PARAM IQ_NOM = 0.00134
.PARAM IQ_SHDN = 0.1u
.PARAM Geq = 18.75u
GVAR VCC VEE VALUE = {(V(SHDN)+ 1e-9)*Geq*V(VCC,VEE)}
GIQ VCC VEE VALUE = {V(SHDN)*IQ_NOM + (1-V(SHDN))*IQ_SHDN}
GOUTP VCC GNDF VALUE = {IF(V(VIMON,GNDF) > 0, V(VIMON)*V(SHDN),0)}
GOUTN GNDF VEE VALUE = {IF(V(VIMON,GNDF) < 0, V(VIMON)*V(SHDN),0)}
.ENDS
*$
.SUBCKT IIBN_OPA320 OUT IN VCC VEE INN GNDF
.PARAM SCALE = 1p
.PARAM IIBtyp = 0.3
.PARAM m1t = 0
.PARAM m2t = 2
.PARAM m3t = 8
.PARAM m4t = 52
.PARAM m1v = -1
.PARAM m2v = 0.001
.PARAM m3v = -10
.PARAM b1v = -0.9
.PARAM b3v = 23
EIIBt NIIBt 0 VALUE = {MAX(1,PWR(2,(TEMP-27)/10))}
*EIIBt NIIBt 0 VALUE = {MAX(MAX(MAX(V(N1t),V(N2t)),V(N3t)),V(N4t))}
Ein Nin 0 VALUE = {V(INN,GNDF)}
E1v N1v 0 VALUE = {m1v*V(Nin) + b1v}
E2v N2v 0 VALUE = {m2v*V(Nin) + IIBtyp}
E3v N3v 0 VALUE = {m3v*V(Nin) + b3v}
E4v N4v 0 VALUE = {MIN(MAX(V(N1v),V(N2v)),V(N3v))}
EIIBv NIIBv 0 VALUE = {V(N4v)/1}
GOUT OUT IN VALUE = {SCALE*(V(NIIBt)*V(NIIBv))}
.ENDS
*$
.SUBCKT FEMT_OPA320 1 2
.PARAM NLFF = 0.7
.PARAM FLWF = 100
.PARAM NVRF = 0.6
.PARAM GLFF={PWR(FLWF,0.25)*NLFF/1164}
.PARAM RNVF={1.184*PWR(NVRF,2)}
.MODEL DVNF D KF={PWR(FLWF,0.5)/1E11} IS=1.0E-16
* END CALC VALS
I1 0 7 10E-3
I2 0 8 10E-3
D1 7 0 DVNF
D2 8 0 DVNF
E1 3 6 7 8 {GLFF}
R1 3 0 1E9
R2 3 0 1E9
R3 3 6 1E9
E2 6 4 5 0 10
R4 5 0 {RNVF}
R5 5 0 {RNVF}
R6 3 4 1E9
R7 4 0 1E9
G1 1 2 3 4 1E-6
C1 1 0 1E-15
C2 2 0 1E-15
C3 1 2 1E-15
.ENDS
*$
.SUBCKT COMPARATOR_OPA320 OUT IN REF GNDF
.PARAM VOUT_MAX = 1
.PARAM VOUT_MIN = 0
.PARAM GAIN = 1e4
EOUT OUT GNDF VALUE = {MAX(MIN(GAIN*V(IN,REF),VOUT_MAX),VOUT_MIN)}
.ENDS
*$

The PGA280 datasheet doesn't spend enough time describing the use of the GPIO pins as simple outputs.  Nowhere does it describe how to configure and write a simple output.  The closest it comes is a note at the top of the register 5 definition for "Write 0x45".

Is the following true?  In order to make all 7 GPIO pins outputs and then write values to them:
1) Send SPI command and data 0x487F to make them all outputs.
2) Send SPI command and data 0x45NN to send out data values 0xNN to GPIO6:0.  
    (e.g. 0x457F for all ones.  0x4500 for all zeroes.  0x4555 for alternate ones and zeros on GPIO6:0.)

Step 2 is never specified explicitly in the datasheet.  I just want to be sure before designing this part in.

Thanks.

I've been having some strange issues with the following circuit

We are using a 0 REFERENCE voltage (in the real circuit as well) and in no place it mentions "thou shalt not ground reference" however is this an issue with the INA322? The circuit doesn't work consistently between ones we had made.

The LTSPICE simulation seems to hint REF wants to NOT be ground (again not explicitly stated in the Data sheet however).

I appreciate a bit of feedback on this.

Stephen

Hi 

I want to know about normal working of  LMP91000 in 1uA input Ozone sensor.

Setting conditions are as follows.

1. Road Resistance: 10 Ohms, Amp gain with external resistors: 330Kohm
2 Using the internal Ref: 5.0V / 2 = 2.5V
3. BIAS: Negative (default), 0%
4. FET OFF
5. OP_MODE = 3lead cell mode

In this condition, the LMP91000 output  do not come out exactly 2.5V, it comes out 2.64 ~ 2.2V from 1uA Ozone sensor in the absence of gas

Since more than 5uA Ozones sensor in the absence of gas comes exactly 2.5V output from LMP91000.

Dropping the accuracy about below the 5uA(1uA~5uA) for LMP91000?
Or am I setting wrong?
Setting is wrong, let me know how to set detailed.

I have confirmed that work well for 95% (more than 5uA Ozones sensor) sensor with LMP91000.

But, I have confirmed that does not work well for 5% (5uA below Ozone Sensor:1uA~5uA) Sensor with LMP91000

PIease, I want to receive a response within a quick time.

Best Regards

MS. 

Hi I am pretty new at this kind of stuff but get the basics of it. I am working on a project that requires using an instrumentation amplifier but I cant seem to get a correct value for the gain I set. Currently I am inputting 100mv with a 5k resistor to set a gain of 45. I should be getting a value of 4.5 V but cant seem to get anything above 1V. I tried using a 500mv resistor as well and the same happens nothing above 1V. Im not getting something in my head that I should probably be considering but can you all help? I've used multiple breadboards, wires, and I have 10 INA122P's and its basically the same thing. Also with small inputs I get waves but all I get is square looking output waves if that helps any

Hello, I'm trying to design a dc voltage amp. with (ideally) 1nV to 1000nV range for a low impedance source. Can you please help me? Which way should I go? Is a zero offset op-amp enough or do I need a discrete stage before? Is there a way to overcome the offset voltage of op-amps? Is there an app note that describes a doable technique of doing this? What topology would you propose? I would appreciate any hints. Thank you! Regards!

Hi Can you please provide the following information for the OPA1632DG4 Part ?

1. Junction Temperature Max (Tj Max)

 2. Typical Power dissipation (Pd typ)

3. Maximum Power dissipation (Pd max)

4. Thermal Resistance Junction to Ambient (Theta JA

5. Thermal Resistance Junction to Board (Theta JB)

6. Thermal Resistance Junction to Case (Theta JC)

7. Weight          

Hi
I am using LMP91200 evluation board and SPIO-4 board for sensor test. In SPIO-4 board contain Spratan-6 XC6SLX16 (FPGA) and Atmel SAM3U microcontroller. These board connect to each other by GPSI 32 pin connector and it connect to my laptop by USB cable. Output of ADC is connected with FPGA. Output of sensor got in sensor AFE software.

I have a dought doubt , When we do the sensor testing which works either microcontroller or FPGA and both.

I am desinging pH meter. If both or single processor will work then FPGA is required for pH meter.

Hello,

I currently am using the LMP91000EVM with SPIO-4 hooked up to my Windows 7 x64 computer running the LMP91000 v2.0.3.0 evaluation software. I am attempting to use the setup with a Nitric Oxide (NO) sensor element from Nemoto. This sensor element has all the same specs as the CityTech 4NT element that is included with the program.

I select the sensor and then tell the program to "Write all registers to board". I then go to the measurement tab and tell the reading to run continuously leaving it on the default display type of "Output Voltage (mV)". I see the bias voltage charge the sensor and finally after about 2-3 minutes it settles out to about 460mV. I stop the reading and switch to display "Concentration (ppm)" and restart the display. The range of the sensor is 250 ppm, I apply a 100 ppm cal gas and will see the reading change maybe 2 or 3 ppm. I know if i adjust the sensitivity and offset I can make the reading start at almost 0 ppm but the sensor never reads more then 2 or 3 ppm.

Is there a setting I am missing or forgetting a step? Any other suggestions I can try? I really like the theory behind this chip but I so far have not had much success with it.

Thanks for any assistance.

Hello everyone,
 
I am trying to design a 100uA-100mA AC current source, stable over 100Hz-100KHz and the AC voltage supply goes from 5mV-4V. 

Ive gone through the other topics on the same issue but no one posted about such a wide range of load. 100Ohms to 100kOhms.

In theory, the current source is suppose to be independant of any load however in practice that's not happening.

Ive tried out the howland circuits but my main question there is, how is it suppose to be independant of load. The current through a changing value of resistor can be constant only if the voltage increases and the voltage of the howland current pump is limited to the supply voltage. Especially in the maximum case (4V,100mA).

Any input on how to go about designing this or what the flaw in my understanding is will be appreciated.

Thanks

Hello,

I am trying to use the INA2321 to amplify signals from two strain gauges - each configured in a quarter bridge circuit. Each circuit is identical to the one in Figure 2 of the datasheet (page 10 and copied below), except that I'm running +3.3V and I'm using both of the provided amplifiers in the dual package.

My gain on both circuits is set to 395X with R1 = 2.05k and R2 = 160k, my bridge circuits (330ohm over 120ohm) both output at around 0.88V (Vin+ and Vin-), and both circuits are provided a 1.25V reference (from the same source).

My question is this: When I disconnect one of my gauges (lower left corner of the above bridge), I see a rise in the shared reference voltage (up as far as 1.58V), an increase in the output voltage of the second circuit, and a change in the resulting gain of the second circuit. I've tried a few different 1.25V references... and though some display better behavior than others, I still see these issues.

I realize that when I do this I'm now operating the first circuit outside of the input common-mode range. Is this what is causing this problem? If so, is there any way to maintain this shared reference and to allow for the disconnect of one of these gauges?

Any insight into this problem would be greatly appreciated!

~Andy