C8051F018-GQR Silicon Laboratories Inc, C8051F018-GQR Datasheet - Page 42

• Manufacturer Part Number: C8051F018-GQR
• Description: IC 8051 MCU 16K FLASH 64TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F018r

Specifications of C8051F018-GQR

• 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: 32
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.8 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Processor Series: C8051F0x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 1.25 KB
• Interface Type: I2C, SMBus, SPI, UART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 4 bit
• Operating Supply Voltage: 2.8 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: C8051F005DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

7. VOLTAGE REFERENCE
The voltage reference circuit consists of a 1.2V, 15ppm/C (typical) bandgap voltage reference generator and a
gain-of-two output buffer amplifier. The reference voltage on VREF can be connected to external devices in the
system, as long as the maximum load seen by the VREF pin is less than 200A to AGND (see Figure 7.1).
If a different reference voltage is required, an external reference can be connected to the VREF pin and the internal
bandgap and buffer amplifier disabled in software. The external reference voltage must still be less than AV+ -
0.3V. The Reference Control Register, REF0CN (defined in Figure 7.2), provides the means to enable or disable
the bandgap and buffer amplifier. The BIASE bit in REF0CN enables the bias circuitry for the ADC while the
REFBE bit enables the bandgap reference and buffer amplifier which drive the VREF pin. When disabled, the
supply current drawn by the bandgap and buffer amplifier falls to less than 1A (typical) and the output of the
buffer amplifier enters a high impedance state. If the internal bandgap is used as the reference voltage generator,
BIASE and REFBE must both be set to 1. If an external reference is used, REFBE must be set to 0 and BIASE
must be set to 1. If the ADC is not being used, both of these bits can be set to 0 to conserve power. The electrical
specifications for the Voltage Reference are given in Table 7.1.
The temperature sensor connects to the highest order input of the A/D converter’s input multiplexer. The TEMPE
bit within REF0CN enables and disables the temperature sensor. While disabled, the temperature sensor defaults to
a high impedance state and any A/D measurements performed on the sensor while disabled result in meaningless
data.
External Equivalent
Load Circuit
AGND
AGND
AV+
RLOAD
R1
Reference
External
Voltage
Circuit
Figure 7.1. Voltage Reference Functional Block Diagram
VREF
TEMPE
REFBE
BIASE
Rev. 1.2
EN
EN
Reference
Generator
2.4V
Bias
EN
AGND
AGND
Sensor
Temp
C8051F018
C8051F019
(to Analog Mux)
(Bias to ADC)
(to ADC)
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