TDA5251F1 Datasheet, PDF (22/88 Pages) Infineon Technologies AG – ASK/FSK 315MHz Wireless Transceiver

TDA5251 F1
Version 1.0
Confidential
Functional Description
2.4.13 Bandgap Reference Circuitry and Powerdown
A Bandgap Reference Circuit provides a temperature stable 1.2V reference voltage for the device.
A power down mode is available to switch off all subcircuits that are controlled by the bidirectional
Powerdown&DataDetect PwdDD pin (pin 27) as shown in the following table. Power down mode
can either be activated by pin 27 or bit D14 in Register 00. In power down mode also pin 28 (DATA)
is affected (see Section 2.4.17).
Table 2-5
PwdDD Pin Operating States
PwdDD
VDD
Ground/VSS
Operating State
Powerdown Mode
Device On
2.4.14 Timing and Data Control Unit
The timing and data control unit contains a wake-up logic unit, an I²C/3-wire microcontroller
interface, a “data valid” detection unit and a set of configuration registers as shown in the
subsequent figure.
I²C / 3Wire
INTERFACE
INTERNAL BUS
13.125 MHz
XTAL-Osz.
RSSI ^{6 Bit}
ADC
RX DATA
DATA VALID
DETECTOR
A M PLITU D E
threshold TH3
FREQUENCY
window
TH1<T_GATE<TH2
FSK DATA
ASK DATA
BLOCK ENABLE
ASK / FSK
RX / TX
CONTROL
LOGIC
POWER ON
SEQUENCER
WAKEUP
LOGIC
32kHz
RC-Osz.
CLKDiv
PwdDD
Data
AskFsk
RxTx
Reset
Figure 2-6 Timing and Data Control Unit
Preliminary Specification
22
logic.wmf
2003-02-18