Overview
The TX91 is a QFN-style solder-down Computer-on-Module from Ka-Ro electronics, part of the QS Family. Measuring just 27mm square with a total height of 2.6mm, the TX91 is designed for cost-optimised industrial applications requiring a compact, secure embedded processing solution. The module uses a QFN lead style with 1mm pitch and 100 pads including a thermal pad, enabling visual solder joint inspection after assembly and single-sided PCB assembly. Powered by the NXP i.MX 91 with an Arm Cortex-A55 core and EdgeLock secure enclave, it delivers robust Linux-capable performance in one of the smallest footprints available.
Key Features
Processor
NXP i.MX 91
Arm Cortex-A55 @ 1.4 GHz
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 style, 100 pads, 1mm pitch
Display
RGB Display Interface
LCD controller support
OS Support
Linux
Ready for application development
Connectivity
Available Variants
| Feature | QS91 (TX91) | QSRZ | QSMP-1570 | QSMP-1350 |
|---|---|---|---|---|
| Processor | NXP i.MX 91 | Renesas RZ/G2L | STM32MP157C | STM32MP135C |
| Primary Core | 1x Cortex-A55 @ 1.4 GHz | 2x Cortex-A55 @ 1.2 GHz | 2x Cortex-A7 @ 650 MHz | 1x Cortex-A7 @ 650 MHz |
| Secondary Core | - | Cortex-M33 @ 200 MHz | Cortex-M4 @ 200 MHz | - |
| RAM | 512 MB LPDDR4 | 512 MB / 1 GB DDR3L | 256 / 512 MB DDR3L | 256 MB DDR3L |
| ROM | 4 GB eMMC | |||
| Display | RGB | RGB + MIPI-DSI | RGB + MIPI-DSI | RGB |
| GPU | - | Yes | Yes | - |
| Video Codec | - | Yes | - | - |
| Security | NXP EdgeLock | Secure Boot, Cryptography | ||
| 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-style module with thermal pad for excellent thermal performance and defined ground plane connection for all signals. Visual solder joint inspection possible after assembly.
Easy PCB Integration
High-speed design compliant. Even 2-layer PCBs can be used thanks to the large ground pad providing a solid ground plane for controlled impedance routing.
EMI Performance
Large ground pad on bottom side provides a defined return path for all signals, minimising loop area and reducing radiation and EMI issues.
Industrial Reflow Compatible
Compatible with industrial standard reflow profile for Pb-free solders. Single-sided assembly with standard contact assignments.
Electrical Characteristics
| Parameter | Min | Max |
|---|---|---|
| Power Supply (VIN) | 3.1V | 3.6V |
| Operating Temperature | -25°C | +85°C |
Documentation
Download the full TX91 datasheet for complete specifications, pinout details, and design guidelines.
Download Datasheet (PDF)