XE8805AMI028LF Semtech, XE8805AMI028LF Datasheet - Page 47

• Manufacturer Part Number: XE8805AMI028LF
• Description: IC DAS 16BIT FLASH 8K MTP 64LQFP
• Manufacturer: Semtech

Specifications of XE8805AMI028LF

• Applications: Sensing Machine
• Core Processor: RISC
• Program Memory Type: FLASH (22 kB)
• Controller Series: XE8000
• Ram Size: 512 x 8
• Interface: UART, USRT
• Number Of I /o: 24
• Voltage - Supply: 2.4 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Supply Voltage Range: 2.4V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 64
• For Use With: XE8000MP - PROG BOARD AND PROSTART2 CARD
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.5.2
7.5.2.1
The Xtal operates with an external crystal of 32’768 Hz.
During Xtal oscillator start-up, the first 32768 cycles are masked. The two bits EnableXtal and ColdXtal in register
RegSysClock control the oscillator.
At power-on reset or during sleep mode, EnableXtal is reset and ColdXtal is set (Xtal oscillator is not selected at
start-up). The user can start Xtal oscillator by setting EnableXtal. When the Xtal oscillator starts, bit ColdXtal is
reset after 32768 cycles. Before ColdXtal is reset by the system, the Xtal frequency precision is not guaranteed.
The Xtal oscillator can be stopped by the user by resetting bit EnableXtal.
When the user enters into sleep mode, the Xtal is stopped.
When an external clock is detected (ExtClk = 1) or the EnExtClock is set 1, the EnableXtal bit can not be set to 1.
7.5.2.2
The crystal oscillator has been designed for a crystal with the specifications given in Table 7-8. The oscillator
precision can only be guaranteed for this crystal.
For safe operation, low power consumption and to meet the specified precision, careful board layout is required:
The oscillator characteristics are given in Table 7-10. The characteristics are valid only if the crystal and board
layout meet the specifications above.
© Semtech 2006
Symbol
Fs
CL
Rm
Cm
C0
Rmp
Q
Symbol
Rh_oscin
Rh_oscout
Rh_
Cp_oscin
Cp_oscout
Cp_
oscin_oscout
oscin_oscout
Keep lines OSCIN and OSCOUT short and insert a VSS line in between them.
Connect the crystal package to VSS.
No noisy or digital lines near OSCIN or OSCOUT.
Insert guards where needed.
Respect the board specifications of Table 7-9.
Xtal oscillator
Xtal configuration
Xtal oscillator specifications
Description
Resonance frequency
CL
frequency
Motional resistance
Motional capacitance
Shunt capacitance
Motional resistance of
6
Quality factor
th
Description
Resistance OSCIN-VSS
Resistance OSCOUT-VSS
Resistance OSCIN-OSCOUT
Capacitance OSCIN-VSS
Capacitance OSCOUT-VSS
Capacitance OSCIN-OSCOUT
overtone (parasitic)
for
nominal
Table 7-9. Board layout specifications.
Table 7-8. Crystal specifications.
Min
Min
30k
1.8
0.7
0.5
0.5
0.2
10
10
50
4
32768
Typ
Typ
50k
8.2
2.5
1.1
40
8
7-6
400k
Max
Max
100
3.2
2.0
3.0
3.0
1.0
15
Unit
Hz
pF
kΩ
fF
pF
kΩ
-
Unit
MΩ
MΩ
MΩ
pF
pF
pF
Comments
Comments
XE8805/05A
www.semtech.com