Silicon Laboratories C8051F344 Manuel D’Utilisation

The C8051F340/1/2/3/4/5/6/7 devices include an on-chip 10-bit SAR ADC with a true differential input mul-
tiplexer. With a maximum throughput of 200 ksps, the ADC offers true 10-bit linearity with an INL of ±1LSB. 
The ADC system includes a configurable analog multiplexer that selects both positive and negative ADC 
inputs. Twenty (48-pin package) or twenty-one (32-pin package) of the Port I/O pins can be used as analog 
inputs to the ADC. Additionally, the on-chip Temperature Sensor output and the power supply voltage 
(V

DD

) are available as ADC inputs. User firmware may shut down the ADC to save power.

Conversions can be started in six ways: a software command, an overflow of Timer 0, 1, 2, or 3, or an 
external convert start signal. This flexibility allows the start of conversion to be triggered by software 
events, a periodic signal (timer overflows), or external HW signals. Conversion completions are indicated 
by a status bit and an interrupt (if enabled). The resulting 10-bit data word is latched into the ADC data 
SFRs upon completion of a conversion.

Window compare registers for the ADC output data can be configured to interrupt the controller when ADC 
data is either within or outside of a specified range. The ADC can monitor a key voltage continuously in 
background mode, but not interrupt the controller unless the converted data is within/outside the specified 
range.

10-Bit

SAR

Timer 1 Overflow

CNVSTR Input

Timer 3 Overflow

(+)

(-)

Configuration, Control, and Data Registers

Timer 0 Overflow

Timer 2 Overflow

Start 

Conversion

000

AD0BUSY (W)

001

010

011

100

101

16

Window Compare

Logic

Window 
Compare
Interrupt

ADC Data 

Registers

End of 
Conversion 
Interrupt

GND

VREF

Positive 

Input 

(AIN+) 
AMUX

VDD

Negative 

Input 

(AIN-) 

AMUX

Temp 

Sensor

Port I/O 

Pins*

Port I/O 

Pins*