Overview
The QS91 is a compact QFN solder-down Computer-on-Module from Ka-Ro electronics, part of the QS Family. Measuring just 27mm x 27mm with only 2.6mm total height, the QS91 is built around the NXP i.MX 91 with a single Cortex-A55 core running at 1.4 GHz and NXP's EdgeLock secure enclave. With 512MB LPDDR4 RAM, 4GB eMMC, and a rich peripheral set including dual CAN-FD, Ethernet, and up to 60 GPIOs, the QS91 is ideally suited for cost-sensitive industrial IoT gateways, secure edge devices, and connected sensor platforms where security, low power, and small size are paramount.
Key Features
Processor
NXP i.MX 91
1x Cortex-A55 @ 1.4 GHz
EdgeLock Secure Enclave
Memory
512MB LPDDR4 RAM
4GB eMMC Flash
Temperature Range
Industrial Grade
-25°C to +85°C
Form Factor
27 x 27 x 2.6 mm
QFN (100 pads, 1mm pitch)
Display
RGB Display Interface
No GPU (cost-optimised)
Security
NXP EdgeLock Secure Enclave
Tamper Detection
Secure Boot
Connectivity
Available Variants
| Feature | QS91 | QSRZ | QSMP-15 | QSMP-13 |
|---|---|---|---|---|
| Processor | NXP i.MX 91 | Renesas RZ/G2L | STM32MP157C | STM32MP135C |
| Primary Core | Cortex-A55 @ 1.4 GHz | 2x Cortex-A55 @ 1.2 GHz | 2x Cortex-A7 @ 650 MHz | Cortex-A7 @ 650 MHz |
| Secondary Core | — | Cortex-M33 @ 200 MHz | Cortex-M4 @ 200 MHz | — |
| RAM | 512MB LPDDR4 | 512MB / 1GB DDR3L | 256MB / 512MB DDR3L | 256MB DDR3L |
| ROM | 4GB eMMC | 4GB eMMC | 4GB eMMC | 4GB eMMC |
| Display | RGB | RGB + MIPI DSI | RGB + MIPI DSI | RGB |
| GPU | — | Mali-G31 | Yes | — |
| Temperature | -25°C to +85°C | -40°C to +85°C | -25°C to +85°C | -25°C to +85°C |
Design Advantages
Solder-Down Design
QFN form factor eliminates connectors and mechanical fasteners. The 100-pad layout at 1mm pitch provides a robust, vibration-resistant connection suitable for harsh industrial environments.
Easy PCB Integration
The compact 27mm x 27mm footprint with standard 1mm pitch pads allows integration onto carrier boards using conventional PCB design tools. Even 2-layer boards can be used for simple applications.
Hardware Security
NXP EdgeLock secure enclave provides hardware root of trust, secure boot, and tamper detection — essential for industrial IoT devices requiring strong security without external security ICs.
QS Pin-Compatible
Standard 27mm QS pinout ensures compatibility across the QS family. Design one baseboard and scale between processors as application requirements evolve.
Electrical Characteristics
| Parameter | Value |
|---|---|
| Power Supply | 3.3V |
| I/O Voltage | 3.3V |
| Operating Temperature | -25°C to +85°C (Industrial) |
| Package | QFN, 27mm x 27mm, 2.6mm height |
| Pad Count | 100 pads + thermal pad |
| Pad Pitch | 1mm |
Documentation
Download the full QS91 datasheet for complete specifications, pinout details, and design guidelines.
Download Datasheet (PDF)