OA Operation
22-5
OA
22.2.4 OA Configurations
The OA can be configured for different amplifier functions with the OAFCx bits.
as listed in Table 22−1.
Table 22−1.OA Mode Select
OAFCx
OA Mode
000
General-purpose op amp
001
Unity gain buffer
010
Reserved
011
Comparator
100
Non-inverting PGA amplifier
101
Reserved
110
Inverting PGA amplifier
111
Differential amplifier
General-Purpose Opamp Mode
In this mode the feedback resistor ladder is isolated from the OAx and the
OAxCTL0 bits define the signal routing. The OAx inputs are selected with the
OAPx and OANx bits. The OAx output is internally connected to the ADC12
input channel as selected by the OAxCTL0 bits.
Unity Gain Mode
In this mode the output of the OAx is connected to R
BOTTOM
and the inverting
input of the OAx providing a unity gain buffer. The non-inverting input is
selected by the OAPx bits. The external connection for the inverting input is
disabled and the OANx bits are don’t care. The OAx output is internally
connected to the ADC12 input channel as selected by the OAxCTL0 bits.
Comparator Mode
In this mode the output of the OAx is isolated from the resistor ladder. R
TOP
is connected to AV
SS
and R
BOTTOM
is connected to AV
CC
. The OAxTAP signal
is connected to the inverting input of the OAx providing a comparator with a
programmable threshold voltage selected by the OAFBRx bits. The
non-inverting input is selected by the OAPx bits. Hysteresis can be added by
an external positive feedback resistor. The external connection for the
inverting input is disabled and the OANx bits are don’t care. The OAx output
is internally connected to the ADC12 input channel as selected by the
OAxCTL0 bits.
Summary of Contents for MSP430x4xx Family
Page 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Page 2: ......
Page 6: ...vi ...
Page 114: ...3 76 RISC 16 Bit CPU ...
Page 304: ...5 20 FLL Clock Module ...
Page 340: ...7 8 Supply Voltage Supervisor ...
Page 348: ...8 8 16 Bit Hardware Multiplier ...
Page 372: ...9 24 32 Bit Hardware Multiplier ...
Page 400: ...10 28 DMA Controller ...
Page 428: ...13 10 Basic Timer1 ...
Page 466: ...15 24 Timer_A ...
Page 522: ...17 30 USART Peripheral Interface UART Mode ...
Page 544: ...18 22 USART Peripheral Interface SPI Mode ...
Page 672: ...23 12 Comparator_A ...
Page 692: ...24 20 LCD Controller ...
Page 746: ...26 28 ADC12 ...