TDA5235
Functional Description
2.4.9.1 Supply Current
In SLEEP Mode, the Master Control Unit switches the crystal oscillator into Low Power
Mode (all internal load capacitors are disconnected) to minimize power consumption.
This is also valid for Self Polling Mode during Off time (SPM_OFF).
Whenever the chip leaves the SLEEP Mode/SPM_OFF (t1), the crystal oscillator
resumes operation in High Precision Mode and requires tCOSCsettle to settle at the trimmed
frequency. At t2 the analog signal path (RF and IF section) and the RF PLL are activated.
At t3 the chip is ready to receive data. The chip requires tRXstartup when leaving SLEEP
Mode/SPM_OFF until the receiver is ready to receive data.
A transient supply current peak may occur at t1, depending on the selected trimming
capacitance. The average supply current drawn during tRFstartdelay is IRF-FE-startup,BPFcal
.
Run Mode*)
SLEEP Mode**)
SPM OFF Time
RX_RUN Signal
Supply
Current
IRun
IRF-FE-startup ,BPFcal
Isleep_low
t1
t2
t3
t
tRFstartdelay
tCOSCsettle
tRXstartup
(Toff)
Ton
(Toff)
*) Run Mode covers the global chip state:sRun Mode Slave/ Receiver active in Self Polling Mode/ Run Mode Self Polling
**) Isleep_low is valid in the chip states: SLEEP / Off time duringSelf Polling Mode
Figure 42
Supply Current Ramp Up/Down
If the IF buffer amplifier or the clock generation feature (PPx pin active) are enabled, the
respective currents must be added.
Data Sheet
71
V1.0, 2010-02-19
INFINEON [ Infineon ]
