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Advance Data Sheet
B900
July 1999
Baseband Signal Processor
Lucent Technologies Inc.
71
6 Device Requirements and Characteristics (continued)
6.3
Recommended Operating Conditions
6.4
Decoupling Requirements
Install a high-quality ceramic 0.01 pF capacitor between each VDD pin and ground. Install each capacitor as close
as possible to the B900 package. Also, install an additional 0.47
F—1.0 F capacitor at only one of the VDD pins.
6.5
Package Thermal Considerations
The recommended operating temperature specified in
Table 89 is based on the maximum power, package type,
and maximum junction temperature. The following equations describe the relationship between these parameters.
If the application’s maximum power is less than the worst-case value, this relationship determines a higher maxi-
mum ambient temperature or the maximum temperature measured at top dead center of the package.
TA = TJ – P x
ΘJA
TTDC = TJ – P x
ΘJ – TDC
where TA is the still-air ambient temperature and TTDC is the temperature measured by a thermocouple at the top
dead center of the package.
Warning: Due to package thermal constraints, proper precautions in the user’s application should be taken
to avoid exceeding the maximum junction temperature of 125 °C. Otherwise, the device will be
affected adversely.
Table 89. Recommended Voltage and Temperature
Minimum
Instruction
Cycle Time
(TMIN)
Temperature
Class
Supply
Voltage
VDD (V)
Ambient
Temperature
TA (°C)
Min
Max
Min
Max
12.5 ns
Commercial
4.5
5.5
0
70
16.7 ns
Commercial
3.0
3.6
0
70
Table 90. Package Thermal Considerations
Package
Parameter
Value
Unit
44-pin PLCC/MQFP Maximum Junction Temperature (TJ) in
125
°C
44-pin PLCC/MQFP Maximum Thermal Resistance in Still-Air-Ambient (
ΘJA)49
°C/W
44-pin PLCC/MQFP Maximum Thermal Resistance, Junction to Top Dead Center (
ΘJ – TDC)
11
°C/W