NXP Semiconductors MC145170DT2

Overview

MC145170DT2 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 and N counters (R: 5–32,767; N: 40–65,535), dual-phase detectors with linear transfer functions, and a robust power-on reset circuit. It operates from 2.7 V to 5.5 V and supports up to 185 MHz input frequency at 5.0 V.

For engineers reviewing the MC145170DT2 datasheet, MC145170DT2 pinout, MC145170DT2 application, or MC145170DT2 equivalent, this page delivers verified electrical specs, TSSOP-16 package mapping, jam-load timing behavior, BitGrabber register architecture, and real-world RF synthesizer use cases - all confirmed from Freescale's Rev. 4 technical data sheet (02/2003).

Technical Context

The MC145170DT2 implements a dual-phase-detector PLL architecture with independent φR and φV outputs and a three-state PDout, all featuring patented dead-zone elimination for linear transfer characteristics. Its BitGrabber register system enables random-access 1-, 2-, or 3-byte serial loading without address bits - supporting C (8-bit), N (16-bit), and R (15-bit) register writes via Din/CLK/ENB.

It integrates on-chip crystal oscillator support (2–15 MHz), programmable REFout scaling, and jam-load synchronization that initializes both R and N counters simultaneously upon new N-register load - preventing erroneous lock states during frequency changes. The improved POR circuit draws ~20 µA extra quiescent current versus MC145170-1 but maintains ≤100 µA total IDD.

Key Specifications

Pinout & Package

TSSOP-16 package (Case 948C), 4.4 mm × 5.0 mm body, 0.65 mm pitch, exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC145170D2 and MC145170P2, the MC145170DT2 offers identical PLL performance in a smaller, surface-mount TSSOP-16 package optimized for high-density RF layouts - enabling tighter VCO placement, lower parasitic inductance on fin/VDD traces, and compatibility with modern reflow processes.

Availability

MC145170DT2 is available at Aetrix Electronics and suitable for HF/VHF radio design, portable transceiver development, and ISM-band wireless sensor applications requiring stable component supply and long-term manufacturability.

Supply support for MC145170DT2 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 embedded processing and analog RF solutions, specializing in automotive, industrial, and communications ICs.

The MC145170DT2 belongs to Freescale's legacy PLL synthesizer product line, engineered specifically for cost-sensitive, high-reliability RF systems requiring flexible serial programming, low-power operation, and robust lock detection - targeting two-way radios, telemetry links, and amateur equipment.

FAQ

What is the maximum input frequency supported by MC145170DT2 at 3.0 V supply?

The MC145170DT2 supports up to 100 MHz on the fin pin at 3.0 V supply voltage, as specified in Table 6 of the Freescale Technical Data (Rev. 4). This limit scales with supply voltage: 185 MHz is achievable only at ≥4.5 V. Operation above these frequencies risks failed lock or increased jitter due to degraded amplifier gain and counter timing margins.

Does MC145170DT2 require external components for crystal oscillator operation?

Yes, MC145170DT2 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 are mandatory for stable oscillation within the 2–15 MHz range - omitting the resistor causes startup failure or erratic frequency drift.

How does the jam-load feature of MC145170DT2 improve frequency switching reliability?

The jam-load feature in MC145170DT2 forces simultaneous initialization of both R and N counters upon any N-register update, ensuring synchronized countdown start and eliminating race conditions that cause false lock or spurious output. This guarantees deterministic lock timing - critical for MC145170DT2-based radios requiring sub-100 ms channel switching without spectral splatter.

Can MC145170DT2 operate with a 2.5 V supply?

No, MC145170DT2 has a minimum operating supply voltage of 2.7 V, as explicitly stated in Table 1 (Comparison) and Table 3 (Electrical Characteristics). Attempting operation at 2.5 V violates the absolute maximum rating and results in undefined behavior - including failure to reset, incorrect register loading, or inability to achieve lock. MC145170-1 supports 2.5 V, but MC145170DT2 does not.

What is the function of the C7 (POL) bit in the MC145170DT2 configuration register?

The C7 (POL) bit in the MC145170DT2 C register controls polarity inversion of the phase detector outputs: when low, PDout goes negative for fV > fR; when high, PDout goes positive for fV > fR. It also swaps φR and φV functionality - enabling hardware-compatible reuse of loop filter designs across different polarity requirements without PCB changes.