Summary of Maxim DAB tuner supports software-defined radio
The MAX2173 is a highly integrated RF-to-bits tuner for DAB, T-DMB, and FM applications. It combines an RF front-end, lowpass filters, mixers, dual ADCs, and digital filtering into a single chip. This design eliminates external components like VCXOs and regulators, reducing cost and space while simplifying DSP interface via I²S output.
Parts used in the MAX2173 Project:
- Dual Analog-to-Digital Converter (ADC)
- Integrated Digital Filtering
- Digitally Controlled Crystal Oscillator (DCXO)
- 1.6V Low Dropout Regulator (LDO)
- 1.2V Low Dropout Regulator (LDO)
- I²S Format Bus Interface
- I²C Interface
- 40-pin TQFN Package (6mm x 6mm)
Description
The MAX2173 is a highly integrated direct-conversion tuner for digital audio broadcast (DAB) and terrestrial digital multimedia broadcast (T-DMB) applications in the 168MHz to 240MHz (VHF band-III) and 1452MHz to 1492MHz (L-band) frequency bands. For FM and DRM+ reception, a low-IF conversion is used, covering a frequency range of 76MHz to 108MHz (FM band). The design integrates lowpass filters, enabling low-power tuner-on-board designs. The mixer and lowpass filtering are followed by a dual ADC and digital filtering. The digital filtering reduces the output data rate and eases the processing load on the DSP. The resulting bit stream is driven off-chip via an I²S format bus.
An integrated digitally controlled crystal oscillator provides more than ±50ppm control range, eliminating the need for a VCXO. The MAX2173 also provides a buffered-reference clock output at the crystal frequency (fREF) or fREF/3.
Two LDOs are integrated into the MAX2173. The 1.6V LDO can be used to power the internal 1.6V circuitry. External circuits can be powered using the 1.2V LDO, eliminating the need for a stand-alone 1.2V regulator.
The MAX2173 is available in a 40-pin TQFN package (6mm x 6mm) with an exposed pad. Electrical performance is guaranteed over the extended -40°C to +85°C temperature range.
- RF to Bits® Solution with I²S Format Output
- Integrated DCXO Provides ±50ppm Control
- Integrated Digital Filtering
- RSSI Output Through I²C or I²S
- Integrated FM/VHF Band-III RF Bandpass Filter
- Fully Integrated AGC Control Loops
- Integrated 1.2V and 1.6V LDOs
- Small Package (6mm x 6mm TQFN)
Applications/Uses
- Automotive DAB Products
- Fixed and Mobile DAB/FM Products
- T-DMB/FM Products
Maxim Integrated Products has designed a tuner IC for digital audio broadcast (DAB) applications which integrates a radio tuner, analogue-to-digital converter (ADC), and digital filtering, and uses a digital I2S output to interface directly to digital signal processors (DSPs).
Dubbed “RF to Bits”, the supplier’s radio platform is designed to allow the implementation of baseband processing using off-the-shelf DSPs.
“This architectural partition will facilitate faster development times and eliminates numerous external components associated with traditional RF tuners to reduce cost, BOM count, and space,” said the supplier.
By integrating ADCs with digital filtering, the MAX2173 reduces the output data rate and eases the processing load on the back-end DSP. The separation between the radio’s front-end and the DSP is intended to simplify system design.
The chips’ RF front-end supports DAB, FM, and Terrestrial Digital Multimedia Broadcast (T-DMB) applications in the FM, VHF band-III, and L-band frequency bands.
For more read: Maxim DAB tuner supports software-defined radio
-
What frequency bands does the MAX2173 support?
It supports VHF band-III (168MHz to 240MHz), L-band (1452MHz to 1492MHz), and FM band (76MHz to 108MHz). -
Does the MAX2173 require an external VCXO?
No, it includes an integrated digitally controlled crystal oscillator that provides ±50ppm control range. -
How does the MAX2173 reduce the processing load on the DSP?
It uses integrated digital filtering to reduce the output data rate before sending the bit stream off-chip. -
Can external circuits be powered by the MAX2173?
Yes, the integrated 1.2V LDO can power external circuits, eliminating the need for a stand-alone regulator. -
What package type is the MAX2173 available in?
It is available in a 40-pin TQFN package measuring 6mm x 6mm with an exposed pad. -
How is the resulting bit stream driven off-chip?
The bit stream is driven off-chip via an I²S format bus. -
What clock outputs does the MAX2173 provide?
It provides a buffered-reference clock output at the crystal frequency or fREF/3. -
Is RSSI output available through specific interfaces?
Yes, RSSI output is available through either I²C or I²S.
