Asahi Kasei Microdevices/AKM AK1224

Overview

The AK1224 from Asahi Kasei Microdevices is a 100–900 MHz double-balanced down-conversion mixer with differential open-drain IF outputs, single-ended RF input, and low-power differential LO input supporting −5 to +5 dBm drive; it delivers 5.5 dB conversion gain, 8.5 dB SSB noise figure, and +16 dBm IIP3 at 21 mA supply current with 4.75–5.25 V operation.

For engineers reviewing the AK1224 datasheet, AK1224 pinout, AK1224 application, or AK1224 equivalent, key selection criteria include RF/IF frequency coverage (100–900 MHz / 20–100 MHz), bias-adjustable linearity-noise tradeoff, open-drain IF output interface requirements, and UQFN-16 package compatibility with RF layout constraints.

Technical Context

The AK1224 implements a double-balanced Gilbert-cell mixer architecture with integrated LO buffer and independent BIAS1/BIAS2 current-setting resistors enabling optimization of IIP3, NF, gain, and IDD across temperature and supply voltage. Its differential LO input accepts either differential or single-ended drive, while RF input is single-ended with external inductor-to-ground matching.

IF outputs are open-drain differential (IFOUTP/IFOUTN), requiring external inductive power feeding and impedance-matching networks-typically LC-based baluns-to convert to single-ended 50 Ω output; the BIAS SELECT pin toggles between BIAS1 and BIAS2 resistor paths to configure operating point.

Key Specifications

Pinout & Package

AK1224 is housed in a 3 mm × 3 mm × 0.60 mm, 0.5 mm pitch 16-pin UQFN package with exposed thermal pad (to be connected to ground). Pin numbering follows standard counter-clockwise convention starting from top-left corner marked "1".

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar down-conversion mixer applications.

Compared with AK1220 and AK1228, the AK1224 uniquely balances +16 dBm IIP3 and 8.5 dB NF within a 5 V, 100–900 MHz niche-making it the preferred choice for VHF/UHF professional radios where both linearity and sensitivity must coexist without voltage or bandwidth compromise.

Availability

AK1224 is available at Aetrix Electronics and suitable for two-way radios, marine communication systems, and disaster-prevention equipment requiring stable component supply, consistent RF performance, and long-term industrial availability.

Supply support for AK1224 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

Asahi Kasei Microdevices Corporation (AKM) is a Japanese semiconductor company specializing in analog, mixed-signal, and RF ICs for communications, audio, and sensor applications.

The AK12xx mixer family-including AK1224-is designed specifically for high-performance, low-power VHF/UHF radio receivers in professional, public safety, and industrial wireless systems.

FAQ

What is the recommended LO drive level for optimal performance of the AK1224?

The AK1224 achieves best linearity–noise balance at LO input levels between −5 dBm and +5 dBm. At +5 dBm, IIP3 peaks near +18 dBm; at −5 dBm, NF remains stable at 8.5 dB while IIP3 drops to +14 dBm. The datasheet specifies −5 to +5 dBm as the recommended operating range, and exceeding +5 dBm risks LO port damage or degraded intermodulation performance. Always verify LO drive with a calibrated source when characterizing the AK1224.

How do I configure the AK1224 for lowest noise figure?

To achieve the lowest noise figure (8.5 dB typ.), configure the AK1224 with a 27 kΩ resistor on BIAS2 and set BIAS SELECT = HIGH, operating at VDD = 5 V and Ta = 25 °C. This yields 21 mA IDD, +16 dBm IIP3, and 5.5 dB gain. Reducing bias current (e.g., 100 kΩ on BIAS1) lowers IDD to 6 mA but increases NF to ~10.5 dB-so minimum NF requires the mid-range bias setting. Ensure proper RF/IF matching and stable 5 V supply decoupling to maintain spec.

Can the AK1224 IF outputs drive a 50 Ω single-ended load directly?

No-the AK1224 IFOUTP and IFOUTN pins are open-drain differential outputs and cannot drive a 50 Ω single-ended load directly. They require external inductive power feeding (e.g., 100 nH RF chokes) and an LC-based balun network (e.g., Murata LQW21HN1ROJ00 + GRM1552C1H100JA01) to convert the differential signal to a 50 Ω single-ended output. Direct connection to 50 Ω will result in no output swing and potential DC contention. Refer to Figure 11 and Table on page 18 of MS1413-E-02 for validated LC values.

What is the function of the exposed thermal pad on the AK1224 UQFN package?

The exposed thermal pad on the underside of the AK1224's 3 mm × 3 mm UQFN package must be soldered to a solid copper ground plane to ensure both thermal dissipation and RF grounding integrity. It connects internally to VSS and serves as the primary return path for RF, LO, and IF currents. Failure to connect this pad degrades noise figure by up to 2 dB, reduces IIP3 by 3–4 dB, and risks thermal runaway at full bias. The datasheet explicitly states "The exposed pad at the center of the backside should be connected to ground."

Does the AK1224 support single-ended LO drive, and how is it implemented?

Yes-the AK1224 supports single-ended LO drive via the LOINP pin while leaving LOINN AC-coupled to ground (e.g., 10 nF capacitor to VSS). The internal LO buffer is designed to accept either true differential LO or single-ended LO applied to LOINP with LOINN terminated-verified in the "LO Input" section of the datasheet (MS1413-E-02, p. 4). Single-ended drive simplifies LO routing in space-constrained layouts but sacrifices ~3–4 dB of LO–RF isolation versus differential drive; system-level testing is recommended.