MAQRF112 Automotive, 300MHz to 450MHz, +10dBm, 1.8V to 3.6V, ASK/FSK Transmitter with Shutdown General Description Features The MAQRF112 is a high-performance, easy to use, true AEC-Q100 Automotive Qualified Data-In, RF-Out, ASK/FSK, phase-locked loop (PLL) 300MHz to 450MHz frequency range based, transmitter IC for automotive applications in the Data rates up to 50kbps ASK/10kbps FSK 300MHz to 450MHz frequency range. These applications 1.8V to 3.6V operating voltage range include remote keyless entry (RKE) and tire pressure monitoring systems (TPMS). The device needs only a low- +10dBm output power (CW) at 3.0V cost crystal to precisely set the desired RF frequency, and 11.5mA of supply current at +10dBm (CW) a few external components for matching the power 6.9mA of supply current at 1kbps (ASK, Manchester) amplifier output to the antenna. 50nA supply current in shutdown mode The MAQRF112 operates over the 1.8V to 3.6V operating Needs only one crystal to set the desired RF frequency range. It delivers +10dBm (CW) output power into a 50 40C to +125C operating temperature range load, while consuming 11.5mA of supply current from a 3.0V power supply. In ASK mode, the device consumes 10-pin MSOP package (4.9mm x 3.0mm) 6.9mA of supply current at a data rate of 1kbps (Manchester 50%). It features a low-power shutdown Applications mode in which the device typically consumes 50nA of supply current. This makes it an ideal solution for battery Remote keyless entry systems (RKE) powered applications. Tire pressure monitoring systems (TPMS) The MAQRF112 is Automotive Qualified (AEC-Q100) and is rated to operate over the 40C to +125C temperature Ordering Information range. For non-automotive applications that do not require AEC-Q100 qualification, consider the MICRF112. For Part Number Temp. Range Package ASK-only applications that do not require shutdown, MAQRF112YMM 40C to +125C 10-Pin MSOP consider the MICRF113 in SOT23-6. Datasheets and support documentation are available on Micrels web site at: www.micrel.com. Typical Application Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MAQRF112 Pin Configuration 10-Pin MSOP (YMM) Pin Description Pin Number Pin Name Pin Function 1 ASK ASK Data Input and PA Enable. When EN is set to a logic-level HIGH and ASK is set to a logic- level HIGH, the power amplifier (PA) is enabled. A logic-level LOW on ASK disables the power amplifier. Apply a data stream less than 50Kbps (Manchester Encoded, 50% duty-cycle) for ASK modulation. To transmit with FSK modulation, both EN and ASK need to be set to a logic-level HIGH, while the FSK pin is modulated. 2 XTLIN Reference Oscillator Input Connection. Connect a crystal between XTLIN and XTLOUT. Connect a load capacitor from XTLIN to ground, based on the recommendations of the crystal manufacturer. 3 XTLOUT Reference Oscillator Output Connection. Connect a crystal between XTLIN and XTLOUT. Connect a load capacitor from XTLOUT to ground, based on the recommendations of the crystal manufacturer. 4 VSS Ground. 5 XTAL MOD FSK Crystal Pulling Switch Connection. For FSK modulation, connect a capacitor between the XTAL MOD pin and XTLOUT. For ASK-only operation, this pin can be left unconnected. 6 FSK FSK Data Input. A logic-level LOW opens the FSK crystal pulling switch, providing high impedance (>1M) between the XTAL MOD pin and VSS (ground). A logic-level HIGH closes the switch, providing low impedance (15) between XTAL MOD and VSS (ground). This parallels the crystal pulling capacitor, C , with the crystal load capacitor, C , and pulls the reference FSK LOAD frequency to achieve FSK modulation. For ASK-only operation, pulling this pin low is recommended. 7 EN Enable/Shutdown Input. A logic-level LOW disables the entire device, placing it in a low-power shutdown mode. A logic-level HIGH enables the crystal oscillator, PLL, voltage-controlled oscillator (VCO), and control blocks, if the supply voltage is above the undervoltage lockout (UVLO) voltage. The power amplifier is enabled when a logic-level HIGH is applied to EN and ASK. 8 VSSPA Power Amplifier Ground. 9 PAOUT Open Collector of Power Amplifier Output. Pull the PA OUT pin to VDD through an inductor to properly bias the output stage. Add a pull-up resistor in series to reduce bias current and to achieve lower output power and lower supply current operation. A matching network is required to match the output to desired load (PCB antenna, wire antenna, or 50 load) to achieve best output power, supply current, and spectral performance. See the Applications Information section for recommended power supply bypassing. 10 VDD Power Supply for Crystal Oscillator, Phase-Locked Loop, Voltage-Controlled Oscillator, and Control Blocks. See the Applications Information section for recommended power supply bypassing. Revision 1.0 February 7, 2013 2