NXP Semiconductors SA58643DP,118

Overview

SA58643DP,118 from NXP Semiconductors is a BiCMOS single-pole double-throw (SPDT) RF switch designed for DC–1 GHz signal routing in 50 Ω systems. It features 1 dB typical insertion loss at 200 MHz, 60 dB off-channel isolation at 100 MHz, and consumes only 170 µA from a 5 V supply-enabling low-power portable transceiver front-ends.

For engineers reviewing the SA58643DP,118 datasheet, SA58643DP,118 pinout, SA58643DP,118 application, or SA58643DP,118 equivalent, key selection criteria include its TTL/CMOS-compatible ENCH1 control, internal 50 Ω OFF-channel termination, bidirectional operation, and TSSOP8 package compatibility with high-density RF layouts.

Technical Context

The SA58643DP,118 integrates on-chip CMOS/TTL drivers and operates as a voltage-controlled SPDT switch: logic HIGH on ENCH1 (Pin 2) connects INPUT (Pin 4) to OUT1 (Pin 8), while logic LOW routes to OUT2 (Pin 5). Its BiCMOS process enables fast 20 ns switching with minimal transient voltage (165 mV p-p).

Internal 50 Ω termination on the OFF channel eliminates external resistors, and AC_GND (Pin 7) requires close-proximity 0.01 µF bypassing to maintain symmetric isolation above 500 MHz. The device maintains stable 50 Ω match (18 dB return loss at 400 MHz) across temperature (−40 °C to +85 °C) and supply (3.0–5.5 V).

Key Specifications

Pinout & Package

TSSOP8 package (SOT505-1): plastic thin shrink small outline, 8 leads, 3 mm body width, 0.65 mm pitch - optimized for automated placement and RF trace routing on 2-layer FR4 boards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF SPDT switch applications.

Compared with QM11036 and SKY13350-374LF, the SA58643DP,118 uniquely combines 5 V TTL/CMOS compatibility, internal 50 Ω termination, and sub-200 µA quiescent current-making it optimal for legacy 5 V portable radios where board space and power budget are constrained.

Availability

SA58643DP,118 is available at Aetrix Electronics and suitable for digital transceiver front-ends, antenna switching modules, and FSK transmitter designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SA58643DP,118 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and mobile applications.

The SA58643DP,118 belongs to NXP's RF front-end switch product line, engineered specifically for low-power, wideband signal routing in portable digital communication systems such as CT2 cordless telephones and TDMA transceivers.

FAQ

What is the maximum RF input power the SA58643DP,118 can handle without compression?

The SA58643DP,118 has a +18 dBm output power at 1 dB gain compression point at 300 MHz, meaning it maintains linear operation up to that RF power level. At 900 MHz, compression occurs at approximately +15 dBm. Exceeding these values causes measurable gain reduction and harmonic distortion, so system-level headroom should be maintained per Table 6 in the datasheet. The SA58643DP,118 is rated for 20 dBm absolute maximum RF power on INPUT, OUT1, or OUT2 pins.

Does the SA58643DP,118 require external termination resistors on the OFF channel?

No-the SA58643DP,118 incorporates internal 50 Ω termination on the OFF channel, eliminating the need for external resistors. This simplifies PCB layout and reduces component count. The internal termination is series-connected with the AC_GND (Pin 7) node, which must be bypassed to ground with a 0.01 µF capacitor placed as close as possible to the pin. External resistors are only required if matching to non-50 Ω impedances (e.g., 75 Ω video systems).

Can the SA58643DP,118 operate with a 3.3 V supply instead of 5 V?

Yes-the SA58643DP,118 supports 3.0 V to 5.5 V supply voltage per Table 4. At 3.3 V, insertion loss increases slightly (e.g., ~1.3 dB at 200 MHz vs. 1.0 dB at 5 V), and isolation decreases by ~5 dB at 1 GHz. The ENCH1 logic thresholds remain valid (VIH ≥ 2.0 V, VIL ≤ 0.8 V), so standard 3.3 V CMOS outputs drive it reliably. However, supply current drops to ~120 µA, improving battery life in 3.3 V systems.

How is the AC_GND (Pin 7) terminal used in the SA58643DP,118 circuit?

AC_GND (Pin 7) is a dedicated RF ground reference-not a DC ground-and must be decoupled to the main GND plane with a 0.01 µF ceramic capacitor placed within 1 mm of the pin. This provides low-impedance return for internal OFF-channel termination and minimizes asymmetry between channels. Incorrect placement (e.g., long trace or missing capacitor) degrades isolation above 500 MHz and causes mismatch in S21/S12 curves, as shown in Figure 9 of the datasheet. The SA58643DP,118 will not achieve specified RF performance without proper AC_GND implementation.

Is the SA58643DP,118 pin-compatible with other NXP RF switches like the SA605 or SA614?

No-the SA58643DP,118 is not pin-compatible with the SA605 (mixer) or SA614 (IF amplifier); those are functionally distinct ICs with different pinouts, power requirements, and signal paths. The SA58643DP,118 has a unique TSSOP8 pin assignment optimized for SPDT switching (e.g., INPUT on Pin 4, OUT1 on Pin 8, AC_GND on Pin 7). Substituting it for SA605 or SA614 would cause incorrect connections, signal routing failure, and potential damage. Always verify pin mapping against Table 2 in the SA58643DP,118 datasheet.