UPSD3433E-40U6 STMicroelectronics, UPSD3433E-40U6 Datasheet - Page 76

• Manufacturer Part Number: UPSD3433E-40U6
• Description: MCU 8BIT 8032 128KB FLASH 80TQFP
• Manufacturer: STMicroelectronics
• Series: µPSDr

Specifications of UPSD3433E-40U6

• Core Processor: 8032
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, IrDA, SPI, UART/USART, USB
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 46
• Program Memory Size: 160KB (160K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP, 80-VQFP
• For Use With: 497-5518 - EVAL BOARD RFID READER497-5218 - KIT DEVELOPMENT FOR UPSD3400497-2381 - CABLE PROGRAMMER FLASH LINK
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: 497-4907

Oscillator and external components
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Note:
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Oscillator and external components
The oscillator circuit of UPSD34xx devices is a single stage, inverting amplifier in a Pierce
oscillator configuration. The internal circuitry between pins XTAL1 and XTAL2 is basically an
inverter biased to the transfer point. Either an external quartz crystal or ceramic resonator
can be used as the feedback element to complete the oscillator circuit. Both are operated in
parallel resonance. Ceramic resonators are lower cost, but typically have a wider frequency
tolerance than quartz crystals. Alternatively, an external clock source from an oscillator or
other active device may drive the UPSD34xx oscillator circuit input directly, instead of using
a crystal or resonator.
The minimum frequency of the quartz crystal, ceramic resonator, or external clock source is
3MHz if the USB is used. The minimum is 8MHz if I
cases. This frequency is f
MCU clock generation on page
The pin XTAL1 is the high gain amplifier input, and XTAL2 is the output. To drive the
UPSD34xx device externally from an oscillator or other active device, XTAL1 is driven and
XTAL2 is left open-circuit. This external source should drive a logic low at the voltage level of
0.3 V
5 V tolerant.
Most of the quartz crystals in the range of 25MHz to 40 MHz operate in the third overtone
frequency mode. An external LC tank circuit at the XTAL2 output of the oscillator circuit is
needed to achieve the third overtone frequency, as shown in
this LC circuit, the crystal will oscillate at a fundamental frequency mode that is about 1/3 of
the desired overtone frequency.
In
overtone mode) do not need the LC circuit components. Since quartz crystals and ceramic
resonators have their own characteristics based on their manufacturer, it is wise to also
consult the manufacturer’s recommended values for external components.
Figure 14 on page 77
CC
or below, and logic high at 0.7V V
crystals which are specified to operate in fundamental mode (not
OSC
, which can be divided internally as described in
68.
CC
UPSD3422, UPSD3433, UPSD3434, UPSD3454
or above, up to 5.5 V V
2
C is used. The maximum is 40MHz in all
Figure 14 on page
CC
. The XTAL1 input is
Section 14:
77. Without