MSP430 OP-AMP SPICE MODELS
==========================

Some members of the MSP430 MCU family have an integrated op amp module (OA).  The OA op amps support front-end analog signal conditioning prior to analog-to-digital conversion.

Features of the OA include:
-   Single supply, low-current operation
-   Rail-to-rail output
-   Software selectable rail-to-rail input
-   Programmable settling time vs power consumption
-   Software selectable configurations
-   Software selectable feedback resistor ladder for PGA implementations

The SPICE models in this zip file may be used in simulations involving the OA module.  Models are provided for PSpice and for TI's TINA simulator (http://focus.ti.com/docs/toolsw/folders/print/tina-ti.html).  


APPLICABLE DEVICES
==================

The devices from which these models were created was the FG461x family.  However, the model could also be used for the op amps in the FG43x, FG42x0, or F22x4 families, since the core op amp designs in each family are the same.  


TINA REQUIREMENTS
=================

If using TINA, v9.x or later is required.  


MODEL RESTRICTIONS
==================

The models are not configurable; each behaves with fixed, predetermined settings of the OA module's registers.  

In every model, rail-to-rail mode is selected (OARRIP bit of the OAxCTL1 register is cleared).  There is no modelling with the rail-to-rail mode disabled.

In all cases, the model behaves as if OAFCx were set to 000b (general-purpose mode).  No feedback resistors are "internally" applied.  

Flexibility in slew rate is provided, in that a separate model is provided for "fast", "medium", and "slow" settings.  (This corresponds with the OAPMx field of the OA module's OAxCTL0 register.)
 

FILES INCLUDED
==============

The zip includes:

*  A set of PSPICE models (*.MOD)
*  A set of TINA models (*.TSM)
*  A set of TINA circuit files that demonstrate usage of the TINA models (*.TSC)

The model sets for PSPICE and TINA each include three models, with each model corresponding with the slow, medium, and fast slew rate settings.  For example:  the TINA model set is comprised of M430GS.tsm, M430GM.tsm, and M430GF.tsm, where *.TSM is the TINA model extension, and S/M/F indicate the speed.  


APPLICATION & EXAMPLES
======================

Each model has an enable line which should be driven to at least 0.5V.  The + and - power rails on the op-amp model should be connected to the Vcc and Gnd voltages of the system.  Note that when using the MSP430's op-amp module, a DVCC voltage of 2.2 - 3.6V must be applied.

For each model, two schematics are created to demonstrate the model:  invert.TSC and transZ.TSC.  The invert.TSC model uses the op-amp as a standard inverting amplifier with a gain of -2.  The transZ.TSC model uses the op-amp as a basic transimpedance amplifier.
