Recommended Operating Conditions; Operating Conditions - Texas Instruments 2000 Series Reference Manual

Recommended Operating Conditions

2.1 Recommended Operating Conditions
Exceeding recommended maximum ratings may lead to permanent damage of
the RFM. The RFM must not be operated in continuous transmit mode when
operated at full power output. Install suitable heatsinks when operating the
RFM at pulse widths smaller than 50%.
Table 2-1 shows the recommended operating conditions.
Symbol
V_VSP Supply voltage of transmitter power stage
Current consumption of transmitter power stage - refer to the formula
I_VSP
below
Peak pulse power input to transmitter power stage
P_VSP
(I_VSP * V_VSP * Duty Cycle)
V_ANT Antenna resonance voltage
Antenna resonance voltage (Pulse width setting ≤ 25%)
V_ANT-25
V_ANT-D1 Antenna resonance voltage for damping option using jumper JP3
V_ANT-ATI Minimum antenna resonance voltage for correct operation of ATI
V_VSL Supply voltage input for logic part
I_VD External current load on internal regulated logic supply voltage output
T_oper Operating free-air temperature range
T_store Storage temperature range
Note: Free-air temperature is the air temperature immediately surrounding the RFM module. If
the module is incorporated into a housing, it must be guaranteed by proper design or
cooling that the internal temperature does not exceed the recommended operating
conditions.
In order to keep power consumption (P_VSP) below 20 W it is advisable to limit I_VSP. The maximum
allowed value, dependent on the configuration, can be determined as follows (in the following examples a
supply voltage of 24 V_VSP is used):
P_VSP
I_VSP =
V_VSP × Duty Cycle
where Duty Cycle =
Total Read Cycle Time
Example 1: Using Standard/Default Settings (≈10 read cycles/second)
20 W
I_VSP = = 1.66 A
24 V × 0.5
Example 2: Configured to No Sync (≈12 read cycles/second)
20 W
I_VSP =
24 V × 0.625
16 Specifications
Table 2-1. Operating Conditions
Parameter
Power on time
Duty Cycle =
100 ms
Duty Cycle =
= 1.33 A
CAUTION
50 ms
= 0.5
50 ms
= 0.625
80 ms
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Min Typ Max Unit
7.0 12.0 24.0 V DC
1.0 1.7 Apeak
20 W
250 380 Vpeak
200 Vpeak
50 60 Vpeak
25 Vpeak
7.0 24.0 V DC
1.0 mA
°C
-25 +70
°C
-40 +85
SCBU022 – November 2002
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