MICRF507

470MHz to 510MHz Low-Power FSK

Transceiver with +10dBm Power Amplifier

RadioWire is a registered trademark of Micrel, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

October 2, 2013

Revision 2.2

General Description

The MICRF507 is a fully-integrated FSK transceiver with

+10dBm power amplifier and transmit/receive switch. The

device is targeted at automated meter reading (AMR)

applications in the China Short Range Device (SRD)

frequency band of 470MHz to 510MHz. The device

supports data rates up to 20kbps with PLL divider

modulation and up to 200kbps with VCO modulation. The

receiver achieves a sensitivity of -113dBm at a data rate of

2.4kbps while only consuming 12mA of supply current.

The integrated power amplifier (PA) delivers +10dBm of

output power while only consuming 21.5mA of supply

current. Power down supply current is a low 0.2µA while

retaining register information and a low 280µA in standby

mode where only the crystal oscillator is enabled.

The receiver of the MICRF507 utilizes a Zero IF (ZIF) I/Q

architecture, integrating a low-noise amplifier (LNA) with

bypass mode, I/Q quadrature mixers, three-pole Sallen-

Key IF channel pre-filters, and six-pole elliptic switched

capacitor IF filters, providing excellent selectivity, adjacent

channel

rejection

and

blocking

performance.

FSK

demodulation is implemented digitally and a synchronizer,

when enabled, recovers the received bit clock. A receive

signal strength indicator (RSSI) circuit indicates the

received signal level over a 50dB range. An integrated

Frequency Error Estimator (FEE) and crystal tuning

capability allow fine tuning of the RF frequency.

The transmitter of the MICRF507 consists of an FSK

modulator

and

power

amplifier

with

output

power

adjustable from +10dBm to -3.5dBm in seven steps.

Modulation can be achieved by applying two sets of PLL

divider ratios or through direct VCO modulation by varying

VCO tank capacitance.

The MICRF507 requires a 2.0V to 2.5V supply voltage,

operates over the -

40˚C to +85˚C temperature range, and

is available in a 32-pin QFN package.

RadioWire

®

Features

• -113dBm sensitivity at 2.4kbps encoded bit rate

• +10dBm power amplifier with seven gain steps

• 12mA receive supply current

• 21.5mA transmit supply current at +10dBm

• 0.2

μA power down current (registers retain settings)

• 280µA standby current (crystal oscillator enabled)

• Data rates up to 20kbps with PLL divider modulation

• Data rates up to 200kbps with VCO modulation

• Integrated transmit and receive (T/R) switch

• LNA with bypass mode

• Zero IF I/Q receiver architecture

• IF pre-amplifiers with DC-offset removal

• Three-pole Sallen-Key IF channel low-pass pre-filter

• Six-pole elliptic switched capacitor IF low-pass filter

• 50kHz to 350kHz programmable baseband bandwidth

• 59dB blocking at ±1MHz offset

• 53dB adjacent channel rejection at ±500kHz offset

• FSK digital demodulator with clock recovery

• 50dB Received Signal Strength Indicator (RSSI)

• Frequency Error Estimator (FEE)

• Reference crystal tuning capability

• 2.0 to 2.5V supply voltage range

• -

40˚C to +85˚C operating temperature range

• Available in 32-pin QFN package

(5.0mm × 5.0mm × 0.85mm)

Applications

• China Short Range Device (SRD) Communications

• Automated Meter Reading (AMR)

• Advanced Metering Infrastructure (AMI)

• Wireless Remote Meter Reading