L9803 STMicroelectronics, L9803 Datasheet - Page 69

• Manufacturer Part Number: L9803
• Description: Super Smart Power Motor Driver With 8-bit Mcu, Ram, Eeprom, Adc, Wdg, Timers, Pwm And H-bridge Driver
• Manufacturer: STMicroelectronics

L9803
5.5
5.5.1
Note:
5.5.2
Note:
10-BIT A/D Converter (AD10)
Introduction
The Analog to Digital converter is a single 10-bit successive approximation converter with 4
input channels. Analog voltage from external sources are input to the converter through
AD2,AD3 and AD4 pins. Channel 1 (AD1) is connected to the internal temperature sensor
(see
The anti aliasing filtering must be accomplished using an external RC filter. The internal
AD1 channel is filtered by an RC network with approx. 1
Functional Description
The result of the conversion is stored in 2 registers: the Data Register High (ADCDRH) and
the Data Register Low (ADCDRL).
The A/D converter is enabled by setting the ADST bit in ADCCSR Register. Bits CH1 and
CH0 of ADCCSR Register select the channel to be converted. The high and low reference
voltage are connected to pins VCC and AGND.
When enabled, the A/D converter performs a complete conversion in 14
clock f
voltage, 10-bit conversion and writing DRH and DRL registers.
When the conversion is completed COCO bit (COnversion COmpleted) is set in ADCCSR.
A conversion starts from the moment ADST bit is set. When a conversion is running it is
possible to write the ADCCSR without stopping the ADC operations, because all the data in
ADCCSR are latched when ADST is set. This property allows to select a different channel to
be processed during the next conversion or to manage the interrupt enable bit. The new
setting will have effect on the next conversion (including interrupt generation)
At the end of the conversion ADST is reset and COCO bit is set.
To start a new conversion the ADST must be set after the completion of the current one. Any
writing to ADST when a conversion is running (COCO=0) has no effect since ADST bit is
automatically reset by the end of conversion event.
Section
CPU
=8Mhz). The total conversion time includes multiplex, sampling of the input
5.5.5).
µ
s time constant.
On-Chip Peripherals
µ
s (with system
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