MICRF507
470MHz to 510MHz Low-Power FSK
Transceiver with +10dBm Power Amplifier
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 MLF
®
package.
RadioWire
®
Features
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-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
0.2μA 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 MLF
®
package
(5.0mm x 5.0mm x 0.85mm)
Applications
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China Short Range Device (SRD) Communications
Automated Meter Reading (AMR)
Advanced Metering Infrastructure (AMI)
Wireless Remote Meter Reading
RadioWire is a registered trademark of Micrel, Inc.
MLF is a registered trademark of Amkor Technology, 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
March 2010
M9999-032210-B
Micrel, Inc.
MICRF507
RadioWire
®
FSK Transceiver Selection Guide................................................................................................................ 4
Ordering Information ......................................................................................................................................................... 4
Block Diagram .................................................................................................................................................................... 4
Pin Configuration ............................................................................................................................................................... 5
Pin Description ................................................................................................................................................................... 5
Absolute Maximum Ratings
(1)
........................................................................................................................................... 7
Operating Ratings
(2)
........................................................................................................................................................... 7
Electrical Characteristics
(4)
............................................................................................................................................... 7
Functional Description .................................................................................................................................................... 10
Control (3-wire) Interface ...................................................................................................................................... 10
Reading ................................................................................................................................................................. 13
Control Interface Timing........................................................................................................................................ 14
Power-on Reset .................................................................................................................................................... 14
Clock Generation ............................................................................................................................................................. 15
Crystal Oscillator (XCO) .................................................................................................................................................. 16
BITSYNC_CLK (Receiver Bit Synchronization Clock).......................................................................................... 17
BITRATE_CLK (Transmitter Bit Rate Clock) ........................................................................................................ 17
MODULATOR_CLK (VCO Modulator Clock)........................................................................................................ 17
Data Interface and Bit Synchronization ......................................................................................................................... 17
Sync_en = 0 .......................................................................................................................................................... 19
Sync_en = 1 .......................................................................................................................................................... 19
Additional Considerations in the Use of Synchronizer (Sync_en = 1) .................................................................. 19
Frequency Synthesizer.................................................................................................................................................... 20
VCO....................................................................................................................................................................... 22
Charge Pump ........................................................................................................................................................ 22
PLL Filter ............................................................................................................................................................... 22
Lock Detect ........................................................................................................................................................... 23
Receiver ............................................................................................................................................................................ 24
Front End............................................................................................................................................................... 24
Sallen-Key Filters .................................................................................................................................................. 25
Switched Capacitor Filter ...................................................................................................................................... 25
RSSI ...................................................................................................................................................................... 25
FEE ....................................................................................................................................................................... 26
XCOtune Procedure Example ......................................................................................................................................... 27
Transmitter........................................................................................................................................................................ 28
Power Amplifier ..................................................................................................................................................... 28
Frequency Modulation........................................................................................................................................... 29
Divider Modulation ................................................................................................................................................ 30
VCO Modulation and the Modulator...................................................................................................................... 30
Modulator Filter ..................................................................................................................................................... 32
System Modes and Initialization..................................................................................................................................... 33
Start-up and Initialization....................................................................................................................................... 33
Modes of Operation............................................................................................................................................... 33
Mode Transitions................................................................................................................................................... 33
Message Coding and Formatting ................................................................................................................................... 34
DC Balanced Line Coding..................................................................................................................................... 34
Message Formatting: Preamble............................................................................................................................ 34
March 2010
2
M9999-032210-B
Micrel, Inc.
MICRF507
Typical Application .......................................................................................................................................................... 35
Bill of Materials................................................................................................................................................................. 36
Layout Considerations .................................................................................................................................................... 37
Layer Definition ..................................................................................................................................................... 37
Grounding.............................................................................................................................................................. 37
RF Traces.............................................................................................................................................................. 37
Supply Routing...................................................................................................................................................... 37
PLL Loop Filter...................................................................................................................................................... 37
Overview of Programming Bits....................................................................................................................................... 38
Detailed Description of Programming Bits.................................................................................................................... 39
Package Information........................................................................................................................................................ 46
March 2010
3
M9999-032210-B
Micrel, Inc.
MICRF507
RadioWire
®
FSK Transceiver Selection Guide
Device
MICRF505
MICRF505L
MICRF506
MICRF507
Frequency Range
850MHz to 950MHz
850MHz to 950MHz
410MHz to 450MHz
470MHz to 510MHz
Maximum
Data Rate
200kbps
200kbps
200kbps
200kbps
Receive Current
13.5mA
13.5mA
12mA
12mA
Supply Voltage
2.0 to 2.5V
2.25 to 5.5V
2.0 to 2.5V
2.0 to 2.5V
Transmit Current
28mA
28mA
21.5mA
21.5mA
Package
MLF-32
MLF-32
MLF-32
MLF-32
Ordering Information
Part Number
MICRF507YML TR
Junction Temperature Range
-40° to +85°C
Package
Pb-Free 32-Pin MLF
®
Block Diagram
March 2010
4
M9999-032210-B
Micrel, Inc.
MICRF507
Pin Configuration
32-Pin MLF
®
Pin Description
Pin Number
1
2
3
4
5
6
7
8, 16, 17, 32
9
10
11
12
13
14
15
18
19
20
21
22
23
24
25
Pin Name
RFGND
PTATBIAS
RFVDD
RFGND
ANT
RFGND
RFGND
NC
CIBIAS
IFVDD
IFGND
ICHOUT
QCHOUT
RSSI
LD
DATACLK
DATAIXO
IO
SCLK
CS
XTALIN
XTALOUT
DIGVDD
O
O
O
O
O
I/O
I/O
I
I
I
I/O
O
I/O
O
Type
Pin Function
LNA and PA ground.
Connection for bias resistor.
LNA and PA power supply.
LNA and PA ground.
Antenna Input/Output.
LNA and PA ground.
LNA and PA ground.
No connect. Leave these pins floating.
Connection for bias resistor.
IF/mixer power supply.
IF/mixer ground.
Test pin.
Test pin.
Received signal strength indicator.
PLL lock indicator.
RX/TX data clock output.
RX/TX data input/output.
3-wire interface data in/output
3-wire interface serial clock.
3-wire interface chip select.
Crystal oscillator input.
Crystal oscillator output or external reference input.
Digital power supply.
March 2010
5
M9999-032210-B