tda5251f1 Infineon Technologies Corporation, tda5251f1 Datasheet - Page 22

• Manufacturer Part Number: tda5251f1
• Description: Ask/fsk 315mhz Wireless Transceiver
• Manufacturer: Infineon Technologies Corporation

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2.4.13
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
2.4.14
The timing and data control unit contains a wake-up logic unit, an I
interface, a “data valid” detection unit and a set of configuration registers as shown in the
subsequent figure.
Figure 2-6
Preliminary Specification
Bandgap Reference Circuitry and Powerdown
Timing and Data Control Unit
PwdDD Pin Operating States
Timing and Data Control Unit
Ground/VSS
PwdDD
VDD
R S S I
BLOCK ENABLE
RX DATA
FSK DATA
ASK DATA
ASK / FSK
RX / TX
A D C
6 B it
INTERNAL BUS
DATA VALID
INTERFACE
DETECTOR
TH1<T
I
thres hold T H 3
FREQUENCY
2
A M P LITU D E
C / 3Wire
window
GATE
SEQUENCER
POWER ON
22
CONTROL
<TH2
LOGIC
Powerdown Mode
Operating State
Device On
13.125 MHz
XTAL-Osz.
WAKEUP
RC-Osz.
LOGIC
32kHz
CLKDiv
PwdDD
Data
AskFsk
RxTx
Reset
Functional Description
2
C/3-wire microcontroller
TDA5251 F1
Version 1.0
2003-02-18
logic.wmf