C8051F901-GU Silicon Laboratories Inc, C8051F901-GU Datasheet - Page 90

• Manufacturer Part Number: C8051F901-GU
• Description: IC MCU 8BIT 8KB FLASH 24QSOP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F9xxr

Specifications of C8051F901-GU

• Program Memory Type: FLASH
• Program Memory Size: 8KB (8K x 8)
• Package / Case: 24-QSOP
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 0.9 V ~ 3.6 V
• Data Converters: A/D 15x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: C8051F9x
• Core: 8051
• Data Ram Size: 768 B
• Interface Type: UART
• Maximum Clock Frequency: 25 MHz
• Number Of Timers: 4
• Operating Supply Voltage: 0.9 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F912DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 24QSOP
• Device Core: 8051
• Family Name: C8051F90x
• Maximum Speed: 25 MHz
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 16
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1847-5

C8051F91x-C8051F90x
7.3.
Comparator response time may be configured in software via the CPTnMD registers described on
“CPT0MD: Comparator 0 Mode Selection” on page 92 and “CPT1MD: Comparator 1 Mode Selection” on
page 94. Four response time settings are available: Mode 0 (Fastest Response Time), Mode 1, Mode 2,
and Mode 3 (Lowest Power). Selecting a longer response time reduces the Comparator active supply
current. The Comparators also have low power shutdown state, which is entered any time the comparator
is disabled. Comparator rising edge and falling edge response times are typically not equal. See
Table 4.14 on page 58 for complete comparator timing and supply current specifications.
7.4.
The Comparators feature software-programmable hysteresis that can be used to stabilize the comparator
output while a transition is occurring on the input. Using the CPTnCN registers, the user can program both
the amount of hysteresis voltage (referred to the input voltage) and the positive and negative-going
symmetry of this hysteresis around the threshold voltage (i.e., the comparator negative input).
Figure 7.3 shows that when positive hysteresis is enabled, the comparator output does not transition from
logic 0 to logic 1 until the comparator positive input voltage has exceeded the threshold voltage by an
amount equal to the programmed hysteresis. It also shows that when negative hysteresis is enabled, the
comparator output does not transition from logic 1 to logic 0 until the comparator positive input voltage has
fallen below the threshold voltage by an amount equal to the programmed hysteresis.
The amount of positive hysteresis is determined by the settings of the CPnHYP bits in the CPTnCN
register and the amount of negative hysteresis voltage is determined by the settings of the CPnHYN bits in
the same register. Settings of 20, 10, 5, or 0 mV can be programmed for both positive and negative
hysteresis. See Section “Table 4.14. Comparator Electrical Characteristics” on page 58 for complete
comparator hysteresis specifications.
90
(Programmed with CP0HYP Bits)
Comparator Response Time
Comparator Hysteresis
Positive Hysteresis Voltage
INPUTS
OUTPUT
VIN+
VIN-
CIRCUIT CONFIGURATION
Positive Hysteresis
CPn-
VIN+
CPn+
VIN-
Disabled
V
OL
V
OH
+
_
Figure 7.3. Comparator Hysteresis Plot
CPn
Positive Hysteresis
Maximum
OUT
Rev. 1.0
Negative Hysteresis
Disabled
Negative Hysteresis
(Programmed by CP0HYN Bits)
Maximum
Negative Hysteresis Voltage