ST10F273Z4 STMicroelectronics, ST10F273Z4 Datasheet - Page 136

• Manufacturer Part Number: ST10F273Z4
• Description: 16-BIT MICROCONTROLLER WITH MAC UNIT, UP TO 832 KBYTES FLASH MEMORY AND UP TO 68 KBYTES RAM
• Manufacturer: STMicroelectronics

Specifications of ST10F273Z4

• Single Voltage Supply: 5 V ±10%

Electrical characteristics
6. DNL, INL, OFS and TUE are tested at V
7. The coupling factor is measured on a channel while an overload condition occurs on the adjacent not selected channels
8. Refer to scheme reported in
24.7.1
136/188
for all other voltages within the defined voltage range.
‘LSB’ has a value of V
For Port5 channels, the specified TUE (± 2LSB) is guaranteed also with an overload condition (see I
occurring on maximum 2 not selected analog input pins of Port5 and the absolute sum of input overload currents on all
Port5 analog input pins does not exceed 10 mA.
For Port1 channels, the specified TUE is guaranteed when no overload condition is applied to Port1 pins: when an overload
condition occurs on maximum 2 not selected analog input pins of Port1 and the input positive overload current on all analog
input pins does not exceed 10 mA (either dynamic or static injection), the specified TUE is degraded (± 7LSB). To get the
same accuracy, the negative injection current on Port1 pins shall not exceed -1mA in case of both dynamic and static
injection.
with the overload current within the different specified ranges (for both positive and negative injection current).
Conversion timing control
When a conversion is started, first the capacitances of the converter are loaded via the
respective analog input pin to the current analog input voltage. The time to load the
capacitances is referred to as sample time. Next the sampled voltage is converted to a
digital value several successive steps, which correspond to the 10-bit resolution of the ADC.
During these steps the internal capacitances are repeatedly charged and discharged via the
V
The current that has to be drawn from the sources for sampling and changing charges
depends on the time that each respective step takes, because the capacitors must reach
their final voltage level within the given time, at least with a certain approximation. The
maximum current, however, that a source can deliver, depends on its internal resistance.
The time that the two different actions during conversion take (sampling, and converting)
can be programmed within a certain range in the ST10F273Z4 relative to the CPU clock.
The absolute time that is consumed by the different conversion steps therefore is
independent from the general speed of the controller. This allows adjusting the A/D
converter of the ST10F273Z4 to the properties of the system:
Fast Conversion can be achieved by programming the respective times to their absolute
possible minimum. This is preferable for scanning high frequency signals. The internal
resistance of analog source and analog supply must be sufficiently low, however.
High Internal Resistance can be achieved by programming the respective times to a
higher value, or the possible maximum. This is preferable when using analog sources and
supply with a high internal resistance in order to keep the current as low as possible. The
conversion rate in this case may be considerably lower, however.
The conversion times are programmed via the upper four bits of register ADCON. Bit fields
ADCTC and ADSTC are used to define the basic conversion time and in particular the
partition between sample phase and comparison phases. The table below lists the possible
combinations. The timings refer to the unit TCL, where f
conversion time includes the conversion itself, the sample time and the time required to
transfer the digital value to the result register.
Table 69.
ADCTC
AREF
00
00
pin.
AREF
ADST
00
01
/1024.
C
A/D converter programming
Figure
38.
TCL * 120
TCL * 140
AREF
Sample
= 5.0 V, V
AGND
= 0V, V
Comparison
TCL * 240
TCL * 280
DD
= 5.0 V. It is guaranteed by design characterization
CPU
TCL * 28
TCL * 16
= 1/2TCL. A complete
Extra
OV
specification)
Total conversion
TCL * 388
TCL * 436
ST10F273Z4