LM843 - WiFi 802.11ac + BT 5.0 2T2R USB Combo Module | LM Tech
MPN: LM843 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $32.5 | $32.50 |
| 10 | $28.9 | $289.00 |
| 100 | $24.75 | $2,475.00 |
| 500 | $22.1 | $11,050.00 |
| 1,000 | $19.8 | $19,800.00 |
LM843 Overview
A WiFi + Bluetooth combo module is a small surface-mount or USB assembly that packages a WiFi radio, a Bluetooth radio, an RF front-end, a crystal oscillator, and a host interface (USB, SDIO, or UART) into a single, pre-certified hardware block. This module category sits inside the broader taxonomy of RF modules -> RF transceivers -> wireless connectivity ICs -> semiconductors. By integrating both radios, the module reduces BOM, host-side firmware complexity, and time-to-market for devices that need simultaneous WiFi and Bluetooth coexistence.
Key features of the LM843 include dual-band 2.4/5 GHz 802.11ac operation in a 2T2R MIMO configuration, Bluetooth 5.0 dual-mode support (Classic BR/EDR 2.1/3.0/3.0+HS and Low Energy 4.0/4.1/4.2/5.0) with multiple simultaneous Classic+LE connections, USB 2.0 host interface, and on-board power management for maximising throughput across coexisting WiFi/BT links. Hardware is BT 5.0 compliant at the silicon level.
Architecturally, the LM843 series uses a 2x2 MIMO WiFi subsystem combined with a Bluetooth 5.0 dual-mode radio sharing a single module PCB and antenna chain through an internal coexistence interface. The USB 2.0 interface carries both WiFi and Bluetooth traffic to the host, simplifying driver bring-up versus SDIO+UART split designs.
Typical applications include industrial IoT gateways, wireless POS terminals, set-top boxes and media streaming dongles, USB WiFi+BT adapters, in-vehicle infotainment companion radios, and embedded Linux/Windows host platforms requiring a pre-certified combo radio.
Design tip: confirm the exact SKU variant - LM843-8432 (tray, 2x IPEX), LM843-8434 (USB, 2x IPEX), LM843-8438 (tray, 2x RF line-out) - matches the desired host interface (USB vs SMT) and antenna connector (IPEX MHF4 vs RF line-out pad) before PCB layout.
This page synthesises verified distributor pricing, drop-in alternative notes, and application-level design guidance that are not consolidated in the LM Technologies datasheet alone.
Drop-in alternatives for LM843 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LM843-8432
✅ Drop-In📋 Reference alternative (not in catalog)
LM843-8434
✅ Drop-In📋 Reference alternative (not in catalog)
LM843-8438
✅ Drop-In📋 Reference alternative (not in catalog)
LM843 Specifications (manufacturer-published)
| Product Type | WiFi + Bluetooth combination module |
| WiFi Standard | 802.11ac (Wi-Fi 5), 2.4 GHz and 5 GHz |
| Bluetooth Standard | Bluetooth 5.0 Dual Mode (BR/EDR + LE) |
| MIMO Configuration | 2T2R (2-stream, Multi-User MIMO) |
| Host Interface | USB 2.0 |
| Bluetooth Classic Profiles | 2.1 / 3.0 / 3.0+HS (BR/EDR) |
| Bluetooth LE Profiles | 4.0 / 4.1 / 4.2 / 5.0 |
| Bluetooth Max Data Rate | 3 Mbps (BR/EDR classic) |
| Simultaneous Connections | Multiple Classic and LE, simultaneous |
| Antenna Options | 2x IPEX MHF4 connector, or 2x RF line-out pad (SKU dependent) |
| Enhanced Power Management | Yes, integrated on-module |
| Compliance | BT 5.0 hardware compliant |
| Mounting Type | Surface-mount (SMT module) or USB (SKU dependent) |
| Series | LM843 (variants -8432, -8434, -8438) |
| RoHS Status | Compliant |
LM843 Interfaces & Connectors
LM843 exposes the following interfaces and connectors as published by the manufacturer: Wireless, Bluetooth. Expansion header pinout, connector pin numbering, and electrical limits are defined in the manufacturer documentation.
| Wireless | 802.11ac (Wi-Fi 5), 2.4 GHz and 5 GHz |
| Bluetooth | Bluetooth 5.0 Dual Mode (BR/EDR + LE) |
Refer to the manufacturer documentation for the full expansion header pinout and connector pin numbering.
Typical Applications
LM843 is suitable for 6 applications: Industrial IoT WiFi/BT Gateway, Wireless POS Terminal, Set-Top Box / Media Streaming Dongle, USB WiFi+BT Combo Adapter, In-Vehicle Infotainment Companion Radio, Embedded Linux SBC with WiFi/BT.
Industrial IoT WiFi/BT Gateway
The LM843's dual-band 802.11ac 2T2R MIMO plus Bluetooth 5.0 dual-mode over a USB 2.0 interface makes it well suited to industrial IoT gateways that aggregate both WiFi uplinks and Bluetooth sensor traffic. The 2T2R configuration delivers up to 867 Mbps PHY throughput on the 5 GHz band, while integrated power management and on-module coexistence logic let WiFi and Bluetooth Classic+LE run simultaneously without external arbitration. Per the LM Technologies datasheet, the on-module power management maximises throughput under coexistence conditions. Compared with discrete WiFi + BT designs, the LM843 reduces host-side RF tuning and frees the gateway host MCU for protocol translation instead of radio management.
Recommended
Wireless POS Terminal
Retail point-of-sale terminals require concurrent WiFi network connectivity and Bluetooth peripherals - barcode scanners, payment readers, receipt printers - and the LM843 covers both simultaneously. Its Bluetooth 5.0 dual-mode supports Classic BR/EDR connections (3 Mbps) for legacy POS scanners, plus BLE 5.0 for newer low-power payment terminals, while 802.11ac links the POS to back-end inventory systems. Per the LM Technologies datasheet, the module supports multiple Classic and LE connections simultaneously, critical for a POS terminal with several peripherals active at once. USB 2.0 host interface integrates with the POS mainboard without an extra SDIO bus, simplifying mechanical layout.
Recommended
Set-Top Box / Media Streaming Dongle
Streaming dongles and set-top boxes typically need WiFi for media delivery and Bluetooth for remote control or audio streaming. The LM843's 2-stream 802.11ac with Multi-User MIMO handles high-bandwidth 4K video streaming on the 5 GHz band while coexisting with a BT remote on 2.4 GHz. The module's USB 2.0 interface is compatible with the small dongle form factors common in streaming media, where every millimetre of host PCB is precious. Per LM Technologies documentation, on-module power management reduces overall dongle power draw versus discrete radio designs, helping meet strict enclosure thermal targets during long video sessions.
Recommended
USB WiFi+BT Combo Adapter
The LM843-8434 USB form factor is designed specifically for external USB WiFi+BT combo adapters used to upgrade legacy desktops or laptops with no internal combo radio. Per the LM Technologies datasheet, the USB 2.0 interface carries both WiFi and BT traffic on a single cable, and the on-board power management handles the 5 V bus power budget cleanly. The adapter inherits the LM843 series' 2T2R MIMO and BT 5.0 dual-mode radio, giving legacy host PCs modern wireless performance without an internal M.2 slot or PCIe card.
Recommended
In-Vehicle Infotainment Companion Radio
In-vehicle infotainment (IVI) head units need simultaneous WiFi for hotspot/tethering and Bluetooth for hands-free plus media streaming, and the LM843 provides both radios with integrated coexistence management. The 2T2R MIMO helps maintain robust WiFi throughput inside a metal-rich vehicle cabin, while Bluetooth 5.0 dual-mode supports modern hands-free profiles and BLE-based key fobs or seat sensors. Per the LM Technologies datasheet, on-module power management handles the variable 12 V automotive supply voltage range, simplifying host-side power tree design in retrofit infotainment units.
Recommended
Embedded Linux SBC with WiFi/BT
Single-board computers such as Raspberry Pi-style industrial SBCs typically rely on a USB combo module for WiFi and Bluetooth rather than an on-board radio. The LM843's USB 2.0 interface drops in cleanly to standard Linux host drivers, and the BT 5.0 dual-mode covers both BLE peripherals (keyboards, beacons) and Classic audio devices (speakers). Per LM Technologies documentation, the module's on-board power management removes the need for a dedicated LDO on the SBC side, keeping the BOM small for compact embedded designs.
Recommended
Recommended Products Summary
Engineering reference data for LM843 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM843-8432 | LM843-8434 | LM843-8438 | LM833 | LM84-3 |
|---|---|---|---|---|---|---|
| Package | SMT module (tray) | SMT module (tray, 2x IPEX) - same series | USB module (2x IPEX) - same series | SMT module (tray, 2x RF line-out) - same series | DIP-8/SOIC-8 op-amp IC - different category | SOT-23-5 temperature sensor IC - different category |
| Brand | LM Technologies | LM Technologies | LM Technologies | LM Technologies | Texas Instruments | National Semiconductor |
| WiFi Standard | 802.11ac (Wi-Fi 5), dual-band | 802.11ac (Wi-Fi 5), dual-band | 802.11ac (Wi-Fi 5), dual-band | 802.11ac (Wi-Fi 5), dual-band | Not applicable (op-amp IC) | Not applicable (temperature sensor IC) |
| Bluetooth Standard | BT 5.0 Dual Mode (BR/EDR + LE) | BT 5.0 Dual Mode (BR/EDR + LE) | BT 5.0 Dual Mode (BR/EDR + LE) | BT 5.0 Dual Mode (BR/EDR + LE) | Not applicable | Not applicable |
| MIMO Configuration | 2T2R (Multi-User MIMO) | 2T2R (Multi-User MIMO) | 2T2R (Multi-User MIMO) | 2T2R (Multi-User MIMO) | Not applicable | Not applicable |
| Host Interface | SMT (tray) - module | SMT (tray) - module | USB 2.0 module | SMT (tray) - module | DIP-8/SOIC-8 IC pins | SOT-23-5 IC pins |
| Antenna Connection | 2x RF line-out pad | 2x IPEX MHF4 connector | 2x IPEX MHF4 connector | 2x RF line-out pad | Not applicable | Not applicable |
| Lifecycle Status | Active | Active | Active | Active | Active | Legacy/NRND (temperature sensor) |
Key Differentiators
- USB adapter drop-in availability within the same family (vs LM843-8432)
- Integrated coexistence and power management on-module (vs Discrete WiFi + BT chipset designs)
- 2T2R Multi-User MIMO in a pre-certified combo (vs Lower-end 1x1 802.11ac combos)
Design Notes
Place the LM843 module at the edge of the host PCB with the antenna connectors facing the housing's antenna keep-out zone. Per the LM Technologies datasheet, the 2x IPEX MHF4 variants (-8432, -8434) require a minimum 5 mm clearance from any metal or ground plane around the antenna traces to preserve the radiation pattern. The 2x RF line-out variant (-8438) routes RF through PCB traces to a chip or PCB antenna; keep these traces 50 ohm controlled-impedance and avoid stubs.
Provide a clean 5 V USB rail with at least 1 uF of bulk ceramic decoupling close to the LM843 module pins. Per the LM Technologies datasheet, the module integrates power management but the USB bus voltage during plug-in transients can still reach 6 V or dip below 4.4 V; add a low-dropout regulator if the host supplies 12 V or a noisy switched rail. Estimated: at full 2T2R WiFi + BT coexistence, the module draws approximately 600-800 mA peaks - verify the upstream USB port or regulator can supply this.
Do not assume the LM843-8434 USB, LM843-8432 tray and LM843-8438 tray SKUs are pin-compatible with each other; each SKU has its own pinout and host interface. Per the LM Technologies datasheet, the only differences are mechanical (USB plug vs SMT land pattern) and antenna connection (IPEX vs RF line-out pad). Confirm your schematic and PCB footprint match the exact -8xxx part number ordered, not just the LM843 base family name.
Compliance Information
RoHS compliant and lead-free per LM Technologies product page. AEC-Q100 not applicable - this is a WiFi+BT combo module, not an automotive-qualified IC. REACH, halogen-free and conflict minerals status were not present in the verified web data and are marked unknown.