Microchip Technology MICRF113YM6-TR

Overview

MICRF113YM6-TR from Micrel is a monolithic ASK transmitter IC operating in the 300–450 MHz UHF band, delivering +10 dBm RF output power into 50 Ω, supporting up to 20 kbps data rate, and functioning across 1.8–3.6 V supply with −40°C to +85°C temperature range-designed for compact key fob and remote control transmitters.

For engineers reviewing the MICRF113YM6-TR datasheet, MICRF113YM6-TR pinout, MICRF113YM6-TR application, or MICRF113YM6-TR equivalent, this page provides verified functional context, validated pin roles, confirmed RF performance metrics, and real-world design constraints including harmonic suppression, oscillator startup time, and undervoltage lockout behavior.

Technical Context

The MICRF113YM6-TR implements a PLL×32 architecture that locks to a crystal reference (9.375–14.0625 MHz), generating stable carrier frequencies across 300–450 MHz. Its integrated power amplifier delivers +10 dBm while maintaining harmonics below −39 dBc at 2nd order and −53 dBc at 3rd order for 315 MHz operation.

It features an enable control block conditioned on PLL lock, amplitude stability, and undervoltage detection (UVLO threshold = 1.6 V), ensuring transmission only under valid operating conditions. The ASK input accepts logic-level signals with VIH = 0.8×VDD and VIL = 0.2×VDD, and supports blanking during VDD ramp-up (500 µs).

Key Specifications

Pinout & Package

Package: SOT-23-6 (YM6), surface-mount, 2.9 mm × 1.6 mm footprint, 1.1 mm height, lead-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MICRF113YM6-TR, Si4010-DT trades crystal dependency for integrated oscillator and protocol support but sacrifices 2 dB output and frequency range flexibility; NB3N502DG offers lower system cost at the expense of requiring external PA and losing 300–450 MHz tunability.

Availability

MICRF113YM6-TR is available at Aetrix Electronics and suitable for fan controllers, remote power switches, and multimedia remote controls requiring stable component supply, long-lifecycle availability, and consistent parametric performance across production batches.

Supply support for MICRF113YM6-TR 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

Micrel Inc. was a U.S.-based analog and RF semiconductor company acquired by Microchip Technology in 2015; known for high-performance RF transceivers, power management, and timing solutions.

The MICRF113YM6-TR belongs to Micrel's QwikRadio™ family of UHF ASK transmitters, engineered specifically for ultra-low-BOM, battery-operated wireless remotes and sensor transmitters demanding regulatory-compliant RF output without external synthesizers.

FAQ

What is the maximum ASK data rate supported by the MICRF113YM6-TR?

The MICRF113YM6-TR supports a maximum ASK bit rate of 20 kbps, corresponding to a minimum pulse width of 50 µs at the ASK input pin. This is confirmed in the Electrical Characteristics table under "ASK Modulation" with test conditions at 2 kbps and 20 kbps, and verified across both 315 MHz and 433.92 MHz operation. The MICRF113YM6-TR maintains clean modulation integrity at this rate without intersymbol interference in typical matching networks.

Does the MICRF113YM6-TR require an external crystal, and what are the acceptable crystal parameters?

Yes, the MICRF113YM6-TR requires an external crystal or ceramic resonator connected between XTLIN and XTLOUT pins. Acceptable crystals must operate between 9.375 MHz and 14.0625 MHz, with ESR from 20 Ω to 300 Ω, C_par from 2–10 pF, and C_mo from 10–40 fF. For example, a 13.560 MHz crystal (used for 433.92 MHz output) or 9.84375 MHz (for 315 MHz) is specified in the Bill of Materials. The MICRF113YM6-TR does not support crystal-less operation.

What is the purpose of the R7 resistor in MICRF113YM6-TR reference designs?

R7 is an external series resistor placed between PAOUT and the output matching network to adjust conducted RF output power. As shown in Tables 2 and 3, varying R7 from 0 Ω to 1 kΩ reduces output from +10 dBm to −3.0 dBm at 433.92 MHz, enabling precise tuning to meet FCC Part 15 or ETSI EN 300 220 conducted emission limits. The MICRF113YM6-TR's PA is designed to interface directly with this resistor-based amplitude control scheme.

How does the MICRF113YM6-TR handle undervoltage conditions?

The MICRF113YM6-TR incorporates an internal undervoltage lockout (UVLO) circuit with a threshold of 1.6 V. When VDD drops below this level, the UVLO block asserts a disable signal to the enable control section, turning off the power amplifier regardless of ASK input state. This prevents distorted or out-of-spec RF output during battery depletion. The MICRF113YM6-TR resumes normal operation only after VDD rises above 1.6 V and oscillator startup completes (~300 µs).

Can the MICRF113YM6-TR drive a PCB loop antenna directly?

Yes, the MICRF113YM6-TR is explicitly validated to drive PCB loop antennas, as demonstrated in Figure 6 and the TX113-1c demo board. Application Note M9999-112310 specifies matching component values (e.g., L1, C5, L4, C7) for both 315 MHz and 433.92 MHz loop configurations. The MICRF113YM6-TR's output stage and harmonic suppression are optimized for direct connection to such antennas without additional filtering stages.