Features: · Single chip 900MHz Radio Transceiver
· Fully integrated filters for all IF, FM discriminator and data filtering
· Image reject mixer & proprietary Low IF architecture reduce the need for RF filtering
· Integrated 1.83GHz frequency synthesizer with internal VCO resonator
· TX/RX calibration for max power transmission
· Modulation compensation for improved sensitivity performance
· PLL Programmed via 3-wire interface
· DC regulation for 2.7V to 5.0V operation (IC performance is reduced from 2.7V to 3.2V)
· PLL lock detect output
· Analog Received Signal Strength Indication (RSSI) output to baseband IC
· Easily upgradable for extended range with ML2751Application· 900MHz DSSS cordless phones
· 900 to 930MHz radio transceivers with ranges from 10 feet to 1000 feet and data rates to 1.5Mbps
· Single IC 900MHz low power radio
· FCC Part 15 compliant radio links
· Portable computer/PDA
· TDD and TDMA radiosPinout
SpecificationsAbsolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied.
VDD, VCC2, VCC5 .................................................... 6.0V
VSS, GND ........................................................... 0 ±0.3V
Junction Temperature .............................................. 150°C
Storage Temperature Range ..................... 65°C to 150°C
Lead Temperature (Soldering, 10s) .......................... 260°C
Normal Temperature Range ........................ -10°C to 60°C
VDD, VCC2, VCC5 Range .............................2.7V to 5.5V
Thermal Resistance (JA) (Note 2) ...................... 100°C/W
Descriptiontelephone transceiver or general purpose Frequency Shift Keying (FSK) radio transceiver. It is designed to work in the 902 to 928MHz ISM band under FCC Part 15 regulations. The ML2721 integrates all the frequency generation, receive and transmit functions for data rates up to 1.5Mbps. A complete radio only requires the addition of an antenna switch. Micro Linear's ML2751 is an integrated 100mW power amplifier and receive LNA with transmit/receive PIN diode drivers, and it can be used with the ML2721 for extended range capability.
The ML2721 contains a proprietary low IF receiver with all channel selectivity. An image reject mixer brings the 915MHz RF signal down to a low IF frequency of 1.024MHz. Then all IF filtering, IF gain, and demodulation is performed at 1.024MHz. This provides all the benefits of direct conversion to baseband and minimizes the need for RF filtering. Also, the ML2721 can operate with either a low cost LC filter or a SAW filter.
A single 1.83GHz synthesizer is used for both the receiver LO and the transmitter. The ML2721 transmitter modulates the VCO with filtered data, and a driver amplifier provides typically 0dBm at 915MHz. The VCO and PLL incorporate the resonator, the active devices, and the tuning circuitry for a completely integrated function. An internal post detection filter and data slicer are also included.
The ML2721 contains its own DC regulation which allows the IC to operate over a wide power supply voltage range. It also has a simple baseband interface for transmit power management, PLL control and detection, and RSSI (Receiver Signal Strength Indication).
ML2721 Data Sheet
