SLAA834B May 2018 – August 2021 MSP430FR2000 , MSP430FR2032 , MSP430FR2033 , MSP430FR2100 , MSP430FR2110 , MSP430FR2111 , MSP430FR2153 , MSP430FR2155 , MSP430FR2310 , MSP430FR2311 , MSP430FR2353 , MSP430FR2355 , MSP430FR2422 , MSP430FR2433 , MSP430FR2475 , MSP430FR2476 , MSP430FR2512 , MSP430FR2522 , MSP430FR2532 , MSP430FR2533 , MSP430FR2632 , MSP430FR2633 , MSP430FR2672 , MSP430FR2673 , MSP430FR2675 , MSP430FR2676 , MSP430FR4131 , MSP430FR4132 , MSP430FR4133 , MSP430FR5720 , MSP430FR5721 , MSP430FR5722 , MSP430FR5723 , MSP430FR5724 , MSP430FR5725 , MSP430FR5726 , MSP430FR5727 , MSP430FR5728 , MSP430FR5729 , MSP430FR5730 , MSP430FR5731 , MSP430FR5732 , MSP430FR5733 , MSP430FR5734 , MSP430FR5735 , MSP430FR5736 , MSP430FR5737 , MSP430FR5738 , MSP430FR5739 , MSP430FR5847 , MSP430FR58471 , MSP430FR5848 , MSP430FR5849 , MSP430FR5857 , MSP430FR5858 , MSP430FR5859 , MSP430FR5867 , MSP430FR58671 , MSP430FR5868 , MSP430FR5869 , MSP430FR5870 , MSP430FR5872 , MSP430FR58721 , MSP430FR5887 , MSP430FR5888 , MSP430FR5889 , MSP430FR58891 , MSP430FR5922 , MSP430FR59221 , MSP430FR5947 , MSP430FR59471 , MSP430FR5948 , MSP430FR5949 , MSP430FR5957 , MSP430FR5958 , MSP430FR5959 , MSP430FR5962 , MSP430FR5964 , MSP430FR5967 , MSP430FR5968 , MSP430FR5969 , MSP430FR59691 , MSP430FR5970 , MSP430FR5972 , MSP430FR59721 , MSP430FR5986 , MSP430FR5987 , MSP430FR5988 , MSP430FR5989 , MSP430FR59891 , MSP430FR5992 , MSP430FR5994 , MSP430FR59941
Two operational amplifiers are available in the MSP430FR231x devices of FR4xx. One op amp is in the Smart Analog Combo (SAC) module, and the other op amp is in the Transimpedance Amplifier (TIA).
The FR231x devices support SAC-L1, which includes only one operational amplifier. Unlike in FR59xx devices, no feedback resistor is included in the MSP430FR231x devices, so external resistors must be added for the amplifier circuit. The SAC supports rail-to-rail input and rail-to-rail output.
The TIA is an amplifier that converts current to voltage. Similar to the SAC-L1, the TIA does not integrate a feedback resistor. One external feedback resistor is needed for the current-to-voltage conversion. TIA supports 1/2- rail input and rail-to-rail output. For the FR231x devices in the PW16 package, there is one dedicated low-leakage input pin for the TIA. This pin supports picoamp-level low-leakage input that improves the accuracy of current conversion.
Unlike in FR59xx devices, FR231x devices have no dedicated analog power or ground pins. If a GPIO needs to drive high current, TI recommends that you do not use the SAC or TIA module at the same time. Using both at the same time affects the power supply of SAC and TIA, which leads to lower performance. For the SAC and TIA layout, keep the traces short and avoid vias. Any toggling pins should be far away from the SAC and TIA pins. The rich internal connections between different modules can also help optimize the layout and reduce pin use. For the internal module connections, see the device-specific data sheet.