High-performance RF transceiver CC900 and its applications (1)

1 Overview

CC900 is United States Chipcon Component company production of single-chip UHF transceiver with high performance, low power, low voltage, wireless communications, is a highly integrated, high sensitivity, high performance RF transceiver chip.

The core collection is mainly applied to engineering and medical Band ISM SRD applications short distance instrument, working frequency range, at 800 ~ 1000MHz, carrier frequency and the transmitter output power can be programmatically determined, its range is-20 ~ 4dBm. The main performance parameters CC900 is as follows:

• Operating frequency programmable settings, in the range 800 ~ 1000MHz;

● Programming set frequency step size for 250Hz;

• Output power programmable devices that range from-20 to 4dBm;

• Receiver sensitivity:-110dBm;

¡Ñadopt 2.7 ~ 3.3V single supply voltage supply;

● FSK modulation capabilities, with rates of 0.3 ~ 9.6kbit/s;

● Emission current 91mA/4dBm;

● Standby current of 2 μ A/3 V;

• Average operating current 230 V/3 A μ;

● Single-mouth antenna, T/R switch;

¡Ñadopt SSOP-28 package.

2 works and pin functions

2.1 works

Internal principle diagram CC900 as shown in Figure 1.

In receive mode, the RF input signal is low noise amplifier (LNA) amplification, and Mixer (MIXER) converted to intermediate frequency (IF) signal. In the band (IF STAGE), the IF signal is amplified and filtering, and finally send modem (DEMOD). Design time you can add a filter IF outside. Signal CC900 demodulation, untreated data output by DID feet. While external microcontrollers through interfaces to control the output data synchronization demodulation and numeric value.

In emission mode, the voltage-controlled oscillator (VCO) output signal directly to the power amplifier (PH).

RF output using frequency shift keying (FSK) modulation from pin DIO input of a digital bit stream can be used to control the frequency of the RF signal. While the device's internal T/R switch you can make the antenna connector and match very easily.

Frequency synthesizers used to produce the local oscillator signal, the signal in the receiver mode is added to the mixer (MIXER), emission mode to power amplifier (PA).

Frequency synthesizer by crystal oscillator, phase detector, charging circuit (CHARGE PUMP), voltage-controlled oscillator (VCO) and frequency divider (/R and/N). Note: you must be connected to an external crystal XOSC PIN. The VCO then you need to add a variable capacitance diode LC circuit. External loop filter improves the flexibility of using the CC900. In addition, the CC900 internal speed with a 3-wire serial interface of digital (CONTROL).