NXP Semiconductors MC145170DT2R2

Overview

MC145170DT2R2 from Freescale Semiconductor is a single-chip PLL frequency synthesizer with serial interface, designed for MF/HF/VHF band RF systems. It features fully programmable R (5–32,767) and N (40–65,535) counters, dual-phase detectors with linear transfer functions, jam-load initialization, and a robust power-on reset circuit. It operates from 2.7–5.5 V and supports up to 185 MHz input at 5.0 V.

For engineers reviewing the MC145170DT2R2 datasheet, MC145170DT2R2 pinout, MC145170DT2R2 application, or MC145170DT2R2 equivalent, this device is selected for RF transceivers requiring fast lock time, low-noise programmable reference synthesis, and flexible serial configuration via BitGrabber™ registers without address bits.

Technical Context

The MC145170DT2R2 implements a dual-phase/frequency detector architecture-supporting both single-ended (PDout) and double-ended (φR/φV) outputs-with patented dead-zone elimination for linear loop response. Its jam-load feature simultaneously initializes both R and N counters on new divide ratio writes, ensuring deterministic phase alignment and preventing erroneous lock states.

It integrates on-chip oscillator support (crystal or external reference), programmable REFout scaling, and per-output enable/disable control via an 8-bit configuration register (C register). The fin amplifier accepts ac- or dc-coupled VCO signals up to 185 MHz at 5.0 V, while internal phase detectors are limited to ≤2.0 MHz output frequencies.

Key Specifications

Pinout & Package

TSSOP-16 package (Case 948C), 4.4 mm × 5.0 mm body, 0.65 mm pitch, exposed pad optional. RoHS-compliant, moisture sensitivity level MSL3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PLL frequency synthesizer applications.

Compared with MC145170P2 and MC145170D2, the MC145170DT2R2 provides superior thermal performance and smaller footprint in TSSOP-16, enabling denser RF layout, improved signal integrity, and reliable operation at maximum rated frequency - making it the optimal choice for volume-manufactured wireless equipment.

Availability

MC145170DT2R2 is available at Aetrix Electronics and suitable for FM transceivers, HF amateur radios, VHF airband comms, and portable two-way radios requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MC145170DT2R2 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 analog and mixed-signal ICs for wireless, automotive, and industrial applications, with deep expertise in RF synthesis and timing solutions.

The MC145170DT2R2 belongs to Freescale's legacy PLL synthesizer product line, engineered specifically for cost-sensitive, high-reliability RF systems demanding programmable LO generation with minimal external components.

FAQ

What is the maximum operating frequency supported by the MC145170DT2R2 at 3.0 V supply?

The MC145170DT2R2 supports up to 100 MHz input frequency on the fin pin when operated at 3.0 V minimum supply, as specified in the Electrical Characteristics table. This allows direct interfacing with VCOs in HF and lower-VHF applications without intermediate prescaling, maintaining phase noise performance and simplifying loop filter design.

Does the MC145170DT2R2 require external components for crystal oscillator operation?

Yes, the MC145170DT2R2 requires external components for crystal operation: two load capacitors (≤30 pF each, including stray capacitance) from OSCin and OSCout to ground, plus a 1.0–5.0 MΩ feedback resistor across OSCin/OSCout. These ensure stable oscillation and linear amplifier biasing per Figure 11 in the datasheet.

How does the jam-load feature improve system reliability in the MC145170DT2R2?

The jam-load feature in the MC145170DT2R2 ensures that both R and N counters begin counting down simultaneously upon loading a new N value, and initializes the phase detectors to a known state. This prevents false lock detection, transient spurs, and unlocked behavior during frequency transitions - critical for fast-hopping or scanning radios where channel switching must be deterministic.

Can the MC145170DT2R2 generate a 10 MHz reference output for an external microcontroller?

Yes, the MC145170DT2R2 can generate a 10 MHz REFout signal when configured with appropriate R-divider settings and crystal frequency (e.g., 8 MHz crystal with /8 division or 10 MHz crystal with /1). REFout is buffered, CMOS-compatible, and programmable via the C register - enabling direct clocking of MCU peripherals without adding a second oscillator.

Is the MC145170DT2R2 pin-compatible with the earlier MC145170-1 variant?

Yes, the MC145170DT2R2 is explicitly stated as pin-for-pin compatible with the MC145170-1. Both share identical pinout, electrical characteristics, and register map. The primary difference is an enhanced power-on reset circuit in the MC145170DT2R2, drawing ~20 µA more quiescent current but offering improved immunity to supply glitches.