C8051F537-IM Silicon Laboratories Inc, C8051F537-IM Datasheet - Page 74

• Manufacturer Part Number: C8051F537-IM
• Description: IC 8051 MCU 2K FLASH 20QFN
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F53xr

Specifications of C8051F537-IM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• Program Memory Size: 2KB (2K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.25 V
• Data Converters: A/D 16x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 20-QFN
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SPI, UART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.25 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12 bit, 16 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: 336-1400

C8051F52x/F52xA/F53x/F53xA
6. Voltage Regulator (REG0)
C8051F52x/F52xA/F53x/F53xAdevices include an on-chip low dropout voltage regulator (REG0). The
input to REG0 at the V
or 2.6 V. When enabled, the output of REG0 appears on the V
can be used to power external devices. On reset, REG0 is enabled and can be disabled by software.
The input (V
tor (4.7 µF + 0.1 µF) to ground. This capacitor will eliminate power spikes and provide any immediate
power required by the microcontroller. The settling time associated with the voltage regulator is shown in
Table 2.5 on page 30.
The voltage regulator can also generate an interrupt (if enabled by EREG0, EIE1.6) that is triggered when-
ever the V
interrupt has no pending flag. The recommended procedure to use the interrupt is as follows:
1. Wait enough time to ensure the V
2. Enable the dropout interrupt (EREG0, EIE1.6) and select the proper priority (PREG0, EIP1.6).
3. If triggered, disable the interrupt in the Interrupt Service Routine (clear EREG0, EIE1.6) and execute all
4. The main application, now running in safe mode, should regularly check the DROPOUT bit
74
necessary procedures to put the system in “safe mode,” leaving the interrupt disabled.
(REG0CN.0). Once it is cleared by the regulator hardware, the application can re-enable the interrupt
(EREG0, EIE1.6) and return to normal mode operation.
REGIN
REGIN
Figure 6.1. External Capacitors for Voltage Regulator Input/Output
input voltage drops below the dropout threshold (see Table 2.5 on page 30). This dropout
) and output (V
REGIN
REG0
V
DD
pin can be as high as 5.25 V. The output can be selected by software to 2.1 V
4.7 µF
4.7 µF
DD
) of the voltage regulator should both be bypassed with a large capaci-
REGIN
input voltage is stable.
Rev. 1.3
.1 µF
.1 µF
DD
pin, powers the microcontroller core, and
VREGIN
V
DD