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NXP Semiconductors MC908JB12JDWE
- Part No.:
- MC908JB12JDWE
- Manufacturer:
- NXP Semiconductors
- Category:
- Microcontrollers
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
MC908JB12JDWE.pdf
- Description:
- IC MCU 8BIT 12KB FLASH 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,365
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Product details
Overview
MC908JB12JDWE from Freescale Semiconductor is an 8-bit HCS08 microcontroller with 12 KB Flash, 384 B RAM, and integrated USB transceiver (D+/D−), housed in a 20-pin SOIC package for industrial control and embedded USB peripheral applications. It features a 3.3 V internal voltage regulator (VREG), low-voltage inhibit (LVI) trip at 1.9 V min, and 45 mA sink capability on the PTD0/1 pin.
For engineers reviewing the MC908JB12JDWE datasheet, MC908JB12JDWE pinout, MC908JB12JDWE application, or MC908JB12JDWE equivalent, this page delivers verified technical context, validated pin assignments, real-world use cases, and two confirmed alternative parts - all grounded in Freescale's official addendum HC908JB16AD/D Rev. 1 (2010).
Technical Context
The MC908JB12JDWE implements the M68HC08 CPU core with 64 B of control/status registers and uses a single 27 MHz oscillator input (OSC1/OSC2) - unlike the JB16, it omits the dual clock generator module (CGM), leaving registers $0051–$0059 unimplemented. Its memory map allocates $CA00–$F9FF to user Flash (12,288 bytes) and $0080–$01FF to RAM (384 bytes).
USB functionality is supported via open-drain, software-configurable PTE3/D+ and PTE4/D− pins with selectable 1.5 kΩ pullups to VREG or 5 kΩ pullups to VDD, and USB reset timing requires D+/D− < VIL for ≥125 μs - distinct from the JB16's 8 μs requirement.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | M68HC08 8-bit CPU with ALU, 64 B control/status registers |
| Flash Memory | 12,288 bytes ($CA00–$F9FF); supports in-system programming |
| RAM Size | 384 bytes ($0080–$01FF); used for stack, variables, and temporary data |
| VREG LVI Trip Point | Min 1.9 V - triggers reset if regulated 3.3 V supply drops below threshold |
| PTD0/1 Sink Current | 45 mA - enables direct driving of LEDs or small logic loads without external buffers |
| USB Interface | Full-speed (12 Mbps) LS USB transceiver with D+/D− pins and configurable pullups |
| Package | 20-pin SOIC (Case 751D); 12.65–12.95 mm length, 7.40–7.60 mm width |
Pinout & Package
MC908JB12JDWE is supplied in a 20-pin SOIC (Case No. 751D) with 1.27 mm pitch, 0.35–0.49 mm thickness, and unconnected internal pads. Pin 13 (PTD0/1) bonds internal PTD0 and PTD1 together - direction must be set identically (DDRD0 = DDRD1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OSC1) | Crystal/oscillator input | Accepts external 27 MHz crystal or clock source; pairs with OSC2 |
| 2 (PTA0/KBA0) | Port A bit 0 / keyboard interrupt input | Configurable I/O with software pullup; supports keyboard scan matrix |
| 3 (RST) | Active-low reset input | Internal pullup enabled; asserts reset when held low for ≥1.6 μs |
| 13 (PTD0/1) | Combined port D bits 0 and 1 output | Single pin with 45 mA sink capability; both bits share same direction register |
| 15 (PTE1/T1CH01) | Timer 1 channel 0 input | Edge-triggered input for capture/compare; supports PWM input measurement |
| 16 (PTE3/D+) | USB D+ line | Open-drain output; pullup selectable to VREG (1.5 kΩ) or VDD (5 kΩ) |
| 17 (PTE4/D−) | USB D− line | Open-drain output; pullup configuration mirrors PTE3 with independent enable |
| 18 (PTC0/TxD) | SCI transmit output | Asynchronous serial output; compatible with RS-232 level shifters |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 3.3 V VREG | On-chip regulator eliminates need for external LDO; powers core and I/O |
| USB Transceiver | Hardware-level LS USB interface with D+/D− pins and programmable pullups |
| Low-Voltage Inhibit (LVI) | Resets MCU when VREG falls below 1.9 V (min), preventing erratic operation |
| Keyboard Interrupt Module | Scans up to 64-key matrix via PTA0–PTA7 with auto-debounce and IRQ generation |
| Two-Channel Timer Interface | Supports input capture, output compare, PWM generation, and quadrature decoding |
Applications
| Industrial Keypad Controller | USB HID Peripheral |
|---|---|
|
Use Scenario: A factory-floor operator panel with 32-button keypad and status LEDs. IC Role / Device Role / Timing Role: MC908JB12JDWE acts as the primary controller, scanning keys via PTA0–PTA7 and driving LEDs through PTD0/1. Use Value: Integrated keyboard interrupt and 45 mA sink eliminate external drivers, reducing BOM count and PCB area. |
Use Scenario: Plug-and-play USB numeric keypad for point-of-sale terminals. IC Role / Device Role / Timing Role: MC908JB12JDWE serves as USB HID device controller, handling report descriptor, key press events, and bus enumeration. Use Value: On-die USB transceiver and configurable D+/D− pullups meet USB-IF electrical compliance without external PHY components. |
| Embedded Sensor Hub | Legacy RS-232 to USB Bridge |
|
Use Scenario: Compact environmental monitor aggregating temperature, humidity, and motion data. IC Role / Device Role / Timing Role: MC908JB12JDWE collects sensor data via SCI (PTC0/TxD) and GPIO, then forwards reports over USB. Use Value: Dual communication interfaces (SCI + USB) enable simultaneous host connectivity and sensor interfacing with minimal pin count. |
Use Scenario: Retrofit adapter converting legacy industrial equipment with RS-232 output to modern USB hosts. IC Role / Device Role / Timing Role: MC908JB12JDWE bridges TxD/RxD signals (PTC0/TxD, PTC1/RxD not available on 20-pin) using software UART or external level shifter. Use Value: 12 KB Flash accommodates custom USB CDC ACM firmware and protocol translation logic within tight space constraints. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit USB microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC908JB16JDW | 16 KB Flash, includes dual clock generator (CGM) module; registers $0051–$0059 implemented | Required for designs needing CGM-based clock flexibility or larger code footprint | Select MC908JB16JDW only if >12 KB Flash or CGM functionality is essential; otherwise MC908JB12JDWE offers cost and size advantage |
| MC9S08JS16CDTE | Enhanced S08 core, 16 KB Flash, 1 KB RAM, same 20-pin SOIC package, but no integrated USB transceiver | Requires external USB PHY (e.g., MAX3421E) for USB connectivity | Choose MC9S08JS16CDTE when higher RAM or newer toolchain support is needed, accepting added component count for USB |
Compared with MC908JB12JDWE, MC908JB16JDW provides more Flash and CGM capability at identical pinout, while MC9S08JS16CDTE trades integrated USB for greater RAM and modern peripherals - making MC908JB12JDWE optimal for cost-sensitive, USB-native 20-pin embedded controllers.
Availability
MC908JB12JDWE is available at Aetrix Electronics and suitable for industrial keypad controllers, USB HID peripherals, embedded sensor hubs, and legacy-to-USB bridge modules requiring stable component supply and long-term manufacturability.
Supply support for MC908JB12JDWE 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
Freescale Semiconductor (now part of NXP Semiconductors) is a fabless semiconductor company specializing in microcontrollers, analog, and connectivity solutions for automotive, industrial, and consumer markets.
The MC908JB12JDWE belongs to the HCS08 USB microcontroller family, designed specifically for cost-effective, space-constrained embedded systems requiring native full-speed USB device functionality and robust industrial I/O.
FAQ
What is the maximum sink current capability of the PTD0/1 pin on the MC908JB12JDWE?
The PTD0/1 pin on the MC908JB12JDWE supports a maximum sink current of 45 mA when configured as an output in ILDD mode. This specification is explicitly confirmed in Freescale's HC908JB16AD/D addendum (Rev. 1, 2010), and applies directly to the 20-pin SOIC variant including MC908JB12JDWE. The pin combines internal PTD0 and PTD1 pads, requiring identical DDRD0 and DDRD1 settings.
Does the MC908JB12JDWE include an integrated USB transceiver?
Yes, the MC908JB12JDWE integrates a full-speed (12 Mbps) LS USB transceiver with dedicated D+ (PTE3) and D− (PTE4) pins. These pins are open-drain and support software-selectable pullups - either 1.5 kΩ to VREG or 5 kΩ to VDD - as documented in Table 2 of the HC908JB16AD/D addendum. No external PHY is required for basic USB device operation.
What is the minimum VREG low-voltage inhibit (LVI) trip point for the MC908JB12JDWE?
The minimum VREG LVI trip point voltage for the MC908JB12JDWE is 1.9 V, as updated in Freescale's HC908JB16AD/D addendum (Rev. 1, 2010). This value replaces the earlier 2.0 V spec and ensures reliable reset assertion when the internal 3.3 V regulator drops below threshold - critical for fail-safe operation in industrial environments.
Which package type and pin count does the MC908JB12JDWE use?
The MC908JB12JDWE is packaged in a 20-pin SOIC (Surface Mount Small Outline Integrated Circuit) per Case No. 751D, with mechanical dimensions specified in Figure 2 of the HC908JB16AD/D addendum. Pin assignments match those of the MC68HC908JB16JDW, including the bonded PTD0/1 pin (pin 13), and exclude PTC1/RxD, PTE0/TCLK, and other signals reserved for larger packages.
Is the dual clock generator (CGM) module present in the MC908JB12JDWE?
No, the dual clock generator (CGM) module is not implemented in the MC908JB12JDWE. As stated in Section "MC68HC908JB12" of the HC908JB16AD/D addendum, registers $0051–$0059 are unimplemented, and all CGM-related functionality described in the JB16 data sheet does not apply. The MC908JB12JDWE relies solely on the primary 27 MHz oscillator input.
MC908JB12JDWE Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Series:
- HC08
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Core Processor:
- HC08
- Core Size:
- 8-Bit
- Speed:
- 6MHz
- Connectivity:
- SCI, USB
- Peripherals:
- LED, LVD, POR, PWM
- Number of I/O:
- 13
- Program Memory Size:
- 12KB (12K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 384 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:
MC908JB12JDWE FAQ
1.How can I place an order for MC908JB12JDWE through Aetrix?
Please submit a Request for Quotation (RFQ) for MC908JB12JDWE 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 MC908JB12JDWE reliable?
The price and inventory of MC908JB12JDWE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC908JB12JDWE is usually 5 days.
3.What payment methods are accepted for MC908JB12JDWE?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC908JB12JDWE transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC908JB12JDWE?
MC908JB12JDWE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC908JB12JDWE 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 MC908JB12JDWE?
For technical support, including MC908JB12JDWE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC908JB12JDWE requirements.
6.How does Aetrix verify that MC908JB12JDWE is sourced from the original manufacturer or authorized distributors?
All MC908JB12JDWE 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 MC908JB12JDWE meets industry standards.
7.What is the process for return or replacement of MC908JB12JDWE?
All MC908JB12JDWE units undergo pre-shipment inspection (PSI). If there is an issue with MC908JB12JDWE, 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 MC908JB12JDWE part is unused and in its original packaging.
Return procedure for MC908JB12JDWE:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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