1 Introduction
Texas Instruments (TI ) TCM4300 IS-54B advanced RF cellular telephone interface circuit (ARCTIC ) provides a baseband interface between the digital signal processor (DSP), the microcontroller, and the RF modulator/demodulator in a dual-mode IS-54B cellular telephone. See the TCM4300 functional block diagram.
In the analog mode, the TCM4300 provides all required baseband filtering as well as transmit D/A conversion and receive A/D conversion using dual 10-bit sigma-delta converters. In addition, a WBD wide-band data (WBD) ±10 kb/s Manchester frequency shift key (FSK) demodulator is provided to allow reduced DSP processing load during subscriber standby mode.
In the digital mode, the TCM4300 accepts I and Q baseband data and performs A/D and D/A conversion and square-root raised-cosine filtering using dual 10-bit sigma-delta converters. The TCM4300 also has a π/4-DQPSK modulation encoder for dibit-to-symbol conversion in the digital transmit mode.
The microcontroller interface is compatible with a wide range of microcontrollers. A microcontroller can be used to communicate with the user interface (keyboard, display, etc.) and to program up to three frequency synthesizers by using the on-chip synthesizer interface circuit.
The TCM4300 provides advanced power control to minimize the power consumption of many dual-mode telephone functional blocks such as the speech codec, FM receiver, I and Q demodulator, transmitter signal processor, and RF power amplifier. In addition, the TCM4300 is designed to reduce system power consumption through low-voltage operation and standby mode.
The TCM4300 is offered in the 100-pin PZ package and is characterized for free-air operation from ±40°C to 85°C.
1.1Features
•Compliance With TIA IS-54B Dual-Mode Cellular Standard
•Baseband Transmit Digital-to-Analog (D/A) Conversion and Receive Analog-to-Digital (A/D) Conversion in Analog Transmit Mode Using Dual 10-Bit Sigma-Delta Converters
•Square Root Raised Cosine (SQRC) Filtering in the Digital Mode Using Dual 10-Bit Sigma-Delta Converters
•π/4-Differential Quadrature Phase-Shift Key (DQPSK) Modulation Encoder in Digital Transmit Mode
•Power Control Supervision for Radio Frequency (RF) Power Amplifier, Automatic Frequency Control (AFC), Automatic Gain Control (AGC), and Synthesizer
•Received Signal Strength Indicator (RSSI) and Battery-Level A/D Conversion Circuitry
•Internal Clock Generation
•Wide-Band Data Clock Recovery and Manchester Decoding
•General-Purpose Digital Signal Processor (DSP) and Microcontroller Interface
•3.3-V and 5-V Operation
•Low Power Consumption
TI and ARCTIC are trademarks of Texas Instruments Incorporated.
