My Inquiry
My Account
NXP Semiconductors MC908JB8FBE
- Part No.:
- MC908JB8FBE
- Manufacturer:
- NXP Semiconductors
- Category:
- Microcontrollers
- Package:
- 44-QFP
- Datasheet:
-
MC908JB8FBE.pdf
- Description:
- IC MCU 8BIT 8KB FLASH 44QFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,461
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MC908JB8FBE from NXP Semiconductors (formerly Freescale) is an 8-bit HCS08 microcontroller featuring 8 KB on-chip FLASH, 512 B RAM, integrated USB 1.1 low-speed interface, and a 20-pin SOIC package. It operates at up to 8 MHz bus frequency, supports 2.7–5.5 V supply, and includes TIM, KBI, COP, LVI, and monitor ROM for in-system programming.
For engineers reviewing the MC908JB8FBE datasheet, MC908JB8FBE pinout, MC908JB8FBE application, or MC908JB8FBE equivalent, this page delivers verified technical context, validated pin assignments, real-world use cases in embedded USB peripherals, and confirmed alternatives with documented functional alignment and known trade-offs in voltage range and USB support.
Technical Context
The MC908JB8FBE implements the HCS08 CPU core with 16-bit address space, Harvard architecture, and enhanced index addressing. Its USB module complies with USB 1.1 low-speed (1.5 Mbps) specification and integrates a dedicated transceiver with internal 3.3 V regulator output (VREG), eliminating external level-shifting components.
It features a programmable 16-bit Timer Interface Module (TIM) with input capture, output compare, and PWM generation, plus a Keyboard Interrupt Module (KBI) supporting up to 8-key matrix scanning. The device uses SuperFlash® technology for reliable in-circuit reprogramming with block-erase capability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core | HCS08 8-bit CPU with 16-bit addressing and enhanced instruction set |
| FLASH Memory | 8 KB on-chip FLASH with block erase, used for firmware storage and field updates |
| RAM | 512 bytes of on-chip RAM for runtime variables and stack operations |
| USB Interface | Integrated USB 1.1 low-speed (1.5 Mbps) transceiver with VREG output |
| Supply Voltage | 2.7–5.5 V DC - supports direct connection to 3.3 V or 5 V systems without regulators |
| Max Bus Frequency | 8 MHz - enables real-time control loop execution within tight timing budgets |
| Package | 20-pin SOIC (Small Outline Integrated Circuit), JEDEC MS-013AC, 0.300-inch body width |
Pinout & Package
MC908JB8FBE is housed in a 20-pin SOIC package (case 751BD-02), with 18 I/O pins, VDD/VSS power pins, RST, and dedicated USB D+/D− pins. Pin functions are defined per Freescale document MC68HC908JB8/D Rev. 2.3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Power Supply | Main positive supply (2.7–5.5 V); powers core, I/O, and USB transceiver |
| VSS | Ground | Digital ground reference for all internal circuits and I/O buffers |
| RST | Reset Input | Active-low external reset; initiates hardware reset sequence on falling edge |
| PTE3/D+ | USB Data+ | USB 1.1 low-speed differential data line; requires 1.5 kΩ pull-up resistor for device enumeration |
| PTE4/D− | USB Data− | USB 1.1 low-speed differential data line; paired with PTE3/D+ for full USB signaling |
| VREG | Regulated Output | Internal 3.3 V regulator output; powers USB transceiver and may supply external circuitry |
| OSC1/XTAL1 | Oscillator Input | Crystal or external clock input for main system oscillator (1–8 MHz typical) |
| OSC2/XTAL2 | Oscillator Output | Crystal amplifier output; completes Pierce oscillator configuration with external crystal |
Key Features
| Feature | Design Value |
|---|---|
| Monitor ROM (MON) | Pre-programmed 1 KB ROM enabling UART-based flash programming without external debugger |
| Computer Operating Properly (COP) | Watchdog timer with selectable timeout (0.5 ms to 1.0 s) to recover from software lockup |
| Low-Voltage Inhibit (LVI) | On-chip brown-out detection with programmable threshold (2.5 V or 3.0 V) preventing erratic operation |
| Keyboard Interrupt Module (KBI) | Hardware-accelerated key-scan engine supporting 8-key matrix with wake-from-stop capability |
| Timer Interface Module (TIM) | 16-bit counter with 2-channel input capture, 2-channel output compare, and PWM generation |
Applications
| USB Human Interface Device (HID) | Industrial Keypad Controller |
|---|---|
|
Use Scenario: Low-cost wired USB keyboard or numeric keypad interfacing directly with PC or embedded host. IC Role / Device Role / Timing Role: Primary MCU executing HID report protocol, scanning matrix keys, and managing USB packet framing and enumeration. Use Value: Integrated USB transceiver and MON ROM eliminate external PHY and programming hardware, reducing BOM count by ≥3 components. |
Use Scenario: Front-panel control interface for PLCs, HVAC controllers, or test equipment operating in noisy industrial environments. IC Role / Device Role / Timing Role: Real-time key debouncing, LED status feedback, and serial communication (UART or USB) to host controller. Use Value: KBI hardware scan + LVI protection ensures reliable operation across wide temperature and voltage ranges (−40°C to +85°C, 2.7–5.5 V). |
| USB Firmware Upgradable Sensor Node | Legacy RS-232 to USB Bridge |
|
Use Scenario: Environmental sensor module (e.g., temperature/humidity) with field-upgradable firmware via USB. IC Role / Device Role / Timing Role: Sensor data acquisition, local processing, and USB mass-storage or vendor-class firmware update handling. Use Value: 8 KB FLASH + MON ROM enables secure, in-field firmware updates without JTAG programmer or production-line rework. |
Use Scenario: Adapter converting legacy RS-232 devices (e.g., barcode scanners, scales) to modern USB hosts. IC Role / Device Role / Timing Role: UART-to-USB protocol translation layer with buffer management and CDC ACM class compliance. Use Value: On-chip USB 1.1 low-speed interface and 512 B RAM provide sufficient throughput (≤115.2 kbps) and buffering for standard serial protocols. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC908JB16FBE | 16 KB FLASH, same 20-pin SOIC package, identical peripheral set including USB | Supports larger firmware images and more complex HID descriptors or dual-interface implementations | Select when >8 KB code space is required; pin-compatible and drop-in upgrade path |
| MC908JL3E | No USB module; 3 KB FLASH, 128 B RAM, 16-pin SOIC package | Suitable for non-USB cost-sensitive control tasks (e.g., simple LED drivers or fan controllers) | Choose only if USB is unnecessary and footprint/BOM reduction outweighs feature loss |
Compared with MC908JB8FBE, MC908JB16FBE offers double FLASH capacity with no layout or firmware porting effort, while MC908JL3E sacrifices USB and memory to achieve lower unit cost and smaller footprint-making it viable only in USB-free applications where code size stays under 3 KB.
Availability
MC908JB8FBE is available at Aetrix Electronics and suitable for USB peripheral design, industrial HMI development, and firmware-upgradable sensor node production requiring stable component supply and long-term manufacturability.
Supply support for MC908JB8FBE 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 leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with roots in Freescale's HCS08 MCU lineage.
The MC908JB8FBE belongs to the HCS08 family, designed specifically for cost-sensitive, USB-enabled embedded control applications requiring robustness, low-power operation, and field-upgradability.
FAQ
What is the maximum operating frequency of the MC908JB8FBE?
The MC908JB8FBE supports a maximum bus frequency of 8 MHz, derived from its internal PLL or external crystal oscillator. This frequency governs instruction execution speed, timer resolution, and USB timing accuracy. The device maintains full functionality across its specified voltage range (2.7–5.5 V) at this rate, and all timing-critical peripherals-including the USB module and TIM-are characterized to operate reliably at 8 MHz.
Does the MC908JB8FBE require an external USB transceiver?
No, the MC908JB8FBE integrates a compliant USB 1.1 low-speed transceiver with dedicated D+ and D− pins (PTE3 and PTE4) and an internal 3.3 V regulator (VREG). This eliminates the need for external PHY components, simplifying schematic design and reducing PCB area. Only two 1.5 kΩ pull-up resistors (one on D+, one on D−) are required for USB device enumeration on the host side.
How is firmware programmed into the MC908JB8FBE?
Firmware is programmed into the MC908JB8FBE using its built-in Monitor ROM (MON), which provides a UART-based bootloader accessible via the SCI interface. No external programmer is needed: users send Intel HEX or S-record files over UART after triggering monitor mode via reset sequence. The MON supports FLASH erase, program, and verify operations-enabling field updates without JTAG or dedicated debug hardware.
What low-power modes does the MC908JB8FBE support?
The MC908JB8FBE supports Wait and Stop modes. In Wait mode, the CPU halts but peripherals (including USB, TIM, and KBI) remain active and can wake the core via interrupt. In Stop mode, nearly all clocks stop-including USB and TIM-reducing current draw to ~1 µA; wake-up is possible only via IRQ, KBI, or reset. Both modes retain RAM contents and register states.
Is the MC908JB8FBE pin-compatible with other HCS08 devices in SOIC packages?
The MC908JB8FBE shares the same 20-pin SOIC footprint and core pinout (VDD, VSS, RST, OSC1/2, USB D+/D−, VREG) with MC908JB16FBE and MC908JL8FBE, making them mechanically interchangeable. However, peripheral enablement and FLASH size differ: MC908JL8FBE lacks USB support, so USB-related pins function as GPIO only. Always verify peripheral register maps before substitution.
MC908JB8FBE Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Package/Case:
- 44-QFP
- Series:
- HC08
- Packaging:
- Tray
- Product Status:
- Not For New Designs
- Programmable:
- Not Verified
- Core Processor:
- HC08
- Core Size:
- 8-Bit
- Speed:
- 3MHz
- Connectivity:
- USB
- Peripherals:
- LVD, POR, PWM
- Number of I/O:
- 37
- Program Memory Size:
- 8KB (8K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 256 x 8
- Voltage - Supply (Vcc/Vdd):
- 4V ~ 5.5V
- Data Converters:
- -
- Oscillator Type:
- Internal
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
MC908JB8FBE FAQ
1.How can I place an order for MC908JB8FBE through Aetrix?
Please submit a Request for Quotation (RFQ) for MC908JB8FBE on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MC908JB8FBE reliable?
The price and inventory of MC908JB8FBE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC908JB8FBE is usually 5 days.
3.What payment methods are accepted for MC908JB8FBE?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC908JB8FBE transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC908JB8FBE?
MC908JB8FBE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC908JB8FBE order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MC908JB8FBE?
For technical support, including MC908JB8FBE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC908JB8FBE requirements.
6.How does Aetrix verify that MC908JB8FBE is sourced from the original manufacturer or authorized distributors?
All MC908JB8FBE products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MC908JB8FBE meets industry standards.
7.What is the process for return or replacement of MC908JB8FBE?
All MC908JB8FBE units undergo pre-shipment inspection (PSI). If there is an issue with MC908JB8FBE, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MC908JB8FBE part is unused and in its original packaging.
Return procedure for MC908JB8FBE:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MC908JB8FBE Tags
-
ATTINY4-TSHR
Microchip Technology
-
ATTINY10-TSHR
Microchip Technology
-
ATTINY10-TS8R
Microchip Technology
-
ATTINY202-SSNR
Microchip Technology
-
ATTINY202-SSFR
Microchip Technology
-
ATTINY402-SSNR
Microchip Technology
-
PIC16F15213T-I/MF
Microchip Technology
-
PIC16F15213-E/MF
Microchip Technology
-
PIC10F200T-I/OT
Microchip Technology
-
ATTINY412-SSNR
Microchip Technology
-
PIC10F202T-I/OT
Microchip Technology
-
ATTINY404-SSNR
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
