AT89LP4052 Atmel Corporation, AT89LP4052 Datasheet - Page 11

• Manufacturer Part Number: AT89LP4052
• Manufacturer: Atmel Corporation

Specifications of AT89LP4052

• Flash (kbytes): 4 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 15
• Spi: 1
• Uart: 1
• Sram (kbytes): 0.25
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 2
• Isp: SPI
• Watchdog: Yes

11. Oscillator Characteristics
3547J–MICRO–10/09
XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier that can be
configured for use as an on-chip oscillator, as shown in
ceramic resonator may be used. For frequencies above 16MHz it is recommended that C1 be
replaced with R1 for improved startup performance. Note that the internal structure of the
devices adds about 10 pF of capacitance to both XTAL1 and XTAL2. The total capacitance on
XTAL1 or XTAL2, including the external load capacitor (C1/C2) plus internal device load, board
trace and crystal loadings, should not exceed 20 pF.
the relationship between clock loading and the respective resulting clock amplitudes.
Figure 11-1. Oscillator Connections
Note:
Figure 11-2. Quartz Crystal Clock Source (A)
C1, C2 = 0–10 pF for Crystals
R1
7
6
5
4
3
2
1
0
0
(A) Low Frequency
= 0–10 pF for Ceramic Resonators
= 4–5 MΩ
C2
C1
4
Quartz Crystal Clock Input
8
~10 pF
~10 pF
Frequency (MHz)
12
Figure
(B) High Frequency
AT89LP2052/LP4052
16
Figure
C2
R1
11-2, 11-3,
11-1. Either a quartz crystal or
20
11-4
C1=C2=0pF
C1=C2=5pF
C1=C2=10pF
and
~10 pF
~10 pF
24
11-5
illustrate
11