tda5235 Infineon Technologies Corporation, tda5235 Datasheet - Page 69

• Manufacturer Part Number: tda5235
• Description: Enhanced Sensitivity Double-configuration Receiver With Digital Baseband Processing
• Manufacturer: Infineon Technologies Corporation

2.4.9
The chip may be operated within a 5 Volts or a 3.3 Volts environment.
Figure 40
For operation within a 5 Volts environment (supply voltage range 1), the chip is supplied
via the VDD5V pin. In this configuration the digital I/O pads are supplied via VDD5V and
a 5 V to 3.3 V voltage regulator supplies the analog/RF section (only active in Run
Modes).
When operating within a 3.3 Volts environment (supply voltage range 2), the VDD5V,
VDDA and VDDD pins must be supplied. The 5 V to 3.3 V voltage regulators are inactive
in this configuration.
The internal digital core is supplied by an additional 3.3 V to 1.5 V regulator.
The regulators for the digital section are controlled by the signal at P_ON (Power On)
pin. A low signal at P_ON disables all regulators and set the IC in Power Down Mode. A
low to high transition at P_ON enables the regulators for the digital section and initiates
a power on reset. The regulator for the analog section is controlled by the Master Control
Unit and is active only when the RF section is active.
To provide data integrity within the digital units, a brownout detector monitors the digital
supply. In case a voltage drop of VDDD below approximately 2.45 V is detected a
RESET will be initiated.
Data Sheet
GNDRF
GNDA
VDDA
P_ON
Power Supply Circuitry
Power Supply
Analog
Section
Voltage Regulator
5 → 3.3 V
OUT
IN
Section
RF
RX_RUN
69
Power-Up
Brownout
Detector
Voltage Regulator
Voltage Regulator
3.3 → 1.5 V
5 → 3.3 V
OUT
OUT
IN
IN
Circuit
Reset-
Internal
Reset
Functional Description
Digital-Core
Digital-I/O
V1.0, 2010-02-19
VDD5V
VDDD
VDDD1V5
GNDD
TDA5235