NXP Semiconductors MC33493MOD315

Overview

MC33493MOD315 from Freescale Semiconductor is a PLL-tuned UHF transmitter IC designed for low-power wireless data transfer in 315 MHz ISM band applications. It integrates a fully embedded VCO, phase-locked loop, RF power amplifier, and digital control interface. Key confirmed parameters include 315 MHz carrier frequency support, OOK/FSK modulation capability, 5 dBm typical output power (315/434 MHz bands), 0.1 nA standby current at 25 °C, and operation from 1.9–3.6 V supply. It serves as the RF transmit stage in automotive keyless entry and industrial remote controls.

For engineers reviewing the MC33493MOD315 datasheet, MC33493MOD315 pinout, MC33493MOD315 application, or MC33493MOD315 equivalent, this page delivers verified technical context, exact pin functions, real-world RF performance metrics, ETSI-compliant design guidance, and validated alternative transmitters for 315 MHz OOK/FSK systems - all grounded in Freescale's Rev. 1.7 product preview documentation.

Technical Context

The MC33493MOD315 implements a fully integrated relaxation-type VCO with on-chip phase-frequency detector (PFD) and loop filter. Its output frequency is precisely determined by f_RFOUT = f_XTAL × PLL divider ratio - 32× for 315 MHz using a 9.84 MHz crystal. Band selection is controlled via the BAND pin (high = 315/434 MHz), and modulation mode (OOK or FSK) is selected by the MODE pin logic level.

FSK is achieved through crystal pulling: the CFSK pin switches external load capacitors to shift crystal frequency, with deviation scaled by the PLL ratio (e.g., ±100 kHz total carrier deviation at 315/434 MHz). The DATACLK output provides a divided-by-64 reference (154 kHz for 9.84 MHz crystal) for microcontroller synchronization, and REXT sets output current and radiated power via a 12 kΩ resistor.

Key Specifications

Pinout & Package

TSSOP-14 package (Case 948G-01), 5.0 × 4.4 mm body, 0.65 mm pitch, 14-pin surface-mount outline per Figure 17.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar UHF transmitter applications.

Compared with MAX1472ATA+T and Si4010-B1B, the MC33493MOD315 offers the lowest standby current (0.1 nA) and dedicated crystal-pulling FSK architecture - making it optimal for long-life, low-data-rate, cost-sensitive 315 MHz keyfob designs requiring ETSI compliance without MCU integration.

Availability

MC33493MOD315 is available at Aetrix Electronics and suitable for automotive keyless entry, industrial remote control, garage door openers, and wireless security sensors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC33493MOD315 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in automotive, industrial, and networking semiconductors, known for high-reliability RF and mixed-signal solutions.

The MC33493MOD315 belongs to Freescale's legacy UHF transmitter family, engineered specifically for battery-powered, ETSI-compliant short-range wireless control in harsh environments - emphasizing ultra-low power, integrated PLL synthesis, and minimal external component count.

FAQ

What is the exact carrier frequency supported by MC33493MOD315?

The MC33493MOD315 is configured for 315 MHz operation using a 9.84 MHz crystal and high logic level on the BAND pin, yielding f_RFOUT = 9.84 MHz × 32 = 314.88 MHz. This aligns with the 315 MHz ISM band and is validated in Table 3 and Figure 12 of the Rev. 1.7 datasheet. The MC33493MOD315 does not support 434 MHz or 868 MHz without hardware reconfiguration.

Does MC33493MOD315 support both OOK and FSK modulation?

Yes, the MC33493MOD315 supports both modulation schemes: OOK is selected by applying low logic to the MODE pin (Pin 14), enabling direct DATA-driven on/off keying of the RF output; FSK is selected with high logic on MODE, using the CFSK pin (Pin 8) to switch external crystal load capacitors and achieve frequency deviation. The MC33493MOD315 achieves ±100 kHz total deviation at 315 MHz per Table 5, Note for parameter 2.36.

What is the recommended REXT resistor value for MC33493MOD315 in 315 MHz applications?

The nominal REXT resistor value for MC33493MOD315 in 315 MHz applications is 12 kΩ, as specified in Table 5 (parameter 2.1) and used in Figure 12's OOK schematic. This yields ~5 dBm output power into a 50 Ω load at 25 °C. The MC33493MOD315 supports REXT values from 12–21 kΩ, with output power varying at –0.35 dB/kΩ (Table 5, parameter 2.12), allowing precise radiated power tuning.

How does the DATACLK output function on MC33493MOD315?

The DATACLK pin (Pin 1) outputs a divided-down version of the crystal oscillator frequency - specifically f_XTAL/64. For the 9.84 MHz crystal used with MC33493MOD315, this yields 154 kHz (Table 4). This signal provides a stable, jitter-controlled clock for microcontroller data sampling and frame timing, eliminating need for external clock dividers. The MC33493MOD315 specifies DATACLK settling time of 800–2000 µs after power-up.

What package type and footprint does MC33493MOD315 use?

The MC33493MOD315 uses a TSSOP-14 package (Case Outline 948G-01), measuring 5.0 × 4.4 mm with 0.65 mm lead pitch. Pin 1 is marked by a dot or notch; the package has two exposed VCC pins (9 and 12) and separate GNDRF (Pin 11) for RF grounding. Mechanical dimensions are detailed in Figure 17 and Table 11 of the Rev. 1.7 datasheet. The MC33493MOD315 is not available in SOIC or QFN variants.