参考电路 4172

MAX2160 ISDB-T Reference Design



Figure 1. The reference design for the MAX2160 tuner plus demodulator.

Figure 1. The reference design for the MAX2160 tuner plus demodulator.
Figure 2. System block diagram.
Figure 2. System block diagram.

Click here for an overview of the wireless components used in a typical radio transceiver.
Click here for an overview of the wireless components used in a typical radio transceiver.

Figure 1. The reference design for the MAX2160 tuner plus demodulator.
Figure 1. The reference design for the MAX2160 tuner plus demodulator.
Figure 2. System block diagram.
Figure 2. System block diagram.

Lab Measurements


Figure 3. Sensitivity measures better than -97dBm.

The tradeoff in sensitivity is also shown when an optional WCDMA or cdma2000® rejection filter is added at the RF input.

Figure 4. A WCDMA blocker rejection filter response. To implement on-board coexistence of ISDB-T with a WCDMA system, additional input filtering is required to reject the cellular transmit-band frequencies. The optional reference-design filtering is a combination of two filters, which provide approximately 47dB of attenuation at the cellular transmit band (marker 4).
Figure 4. A WCDMA blocker rejection filter response.

To implement on-board coexistence of ISDB-T with a WCDMA system, additional input filtering is required to reject the cellular transmit-band frequencies. The optional reference-design filtering is a combination of two filters, which provide approximately 47dB of attenuation at the cellular transmit band (marker 4).

Figure 5. CDMA-2000 blocker rejection filter response. To implement on-board coexistence of ISDB-T with a cdma2000 system in a handheld application, additional input filtering is required to reject the cellular transmit-band frequencies. The optional reference-design filter provides approximately 42dB of attenuation at cdma2000 transmit frequencies (marker 4).
Figure 5. CDMA-2000 blocker rejection filter response.

To implement on-board coexistence of ISDB-T with a cdma2000 system in a handheld application, additional input filtering is required to reject the cellular transmit-band frequencies. The optional reference-design filter provides approximately 42dB of attenuation at cdma2000 transmit frequencies (marker 4).

Additional Measurements

Parameter Conditions Target Measured Units
Maximum Input UHF: Ch. 13, Ch. 33, Ch. 52 0 8.9, 8.2, 7.3 dBm
Adjacent Channel Selectivity
(Desired: -70dBm)
UHF: Ch. 13, Ch. 33, Ch. 52 35 45, 47, 45 dBc
WCDMA Blocker Performance UHF: Ch. 13, Ch. 33, Ch. 52 24 23.5, 24, 24 dBm
cdma2000 Blocker Performance UHF: Ch. 13, Ch. 33, Ch. 52 10 21, 21, 21 dBm

ISDB-T Frequency Plan

Figure 6. The ISDB-T RF signal is broadcast in the UHF band, as shown above. The channel spacing is 6MHz.
Figure 6. The ISDB-T RF signal is broadcast in the UHF band, as shown above. The channel spacing is 6MHz.

Detailed Description

The MAX2160/MAX2160EGB tuner ICs are designed for use in Japanese mobile digital-TV (ISDB-T single-segment) applications. The devices directly convert UHF band signals to a low-IF by using a broadband I/Q downconverter. The operating frequency range extends from 470MHz to 770MHz.

The MAX2160/MAX2160EBG support both I/Q low-IF interfaces and single low-IF interfaces. The devices are thus universal tuners for various digital demodulator implementations.

The MAX2160/MAX2160EBG integrate LNA, RF and low-IF variable-gain amplifiers (VGAs), I and Q downconverting mixers, and bandpass filters providing in excess of 42dB of image rejection. The parts operate with either high-side or low-side local oscillator (LO) injection. The devices' VGAs provide in excess of 100dB of gain-control range.

The MAX2160/MAX2160EBG also have fully monolithic VCOs and tank circuits, and a complete frequency synthesizer. A XTAL oscillator and separate TCXO input buffer are also included. The devices operate with XTAL/TCXO oscillators from 13MHz to 26MHz, which enable the shared use of a VC-TCXO in cellular handset applications. Additionally, a divider is provided for the XTAL/TCXO oscillator, thus allowing for a simple and low-cost interface to various channel decoders.

 
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MAX2160
ISDB-T单段、低IF调谐器

  • 低噪声系数:< 4dB (典型值)
  • 高动态范围:-98dBm至0dBm
  • 高端或低端LO注入