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NXP Semiconductors P87C51X2BBD,157
- Part No.:
- P87C51X2BBD,157
- Manufacturer:
- NXP Semiconductors
- Category:
- Microcontrollers
- Package:
- 44-LQFP
- Datasheet:
-
P87C51X2BBD,157.pdf
- Description:
- IC MCU 8BIT 4KB OTP 44LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,054
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Product details
Overview
P87C51X2BBD,157 from Philips Semiconductors is a 4 KB OTP-based 8-bit 80C51 microcontroller with 128 B RAM, 32 I/O lines, three 16-bit timers/counters, and full-duplex UART - operating at up to 33 MHz (12-clock mode) across 2.7–5.5 V supply. It supports both 6- and 12-clock operation, idle/power-down low-power modes, and is packaged in 44-pin LQFP for industrial control and embedded instrumentation.
For engineers reviewing the P87C51X2BBD,157 datasheet, P87C51X2BBD,157 pinout, P87C51X2BBD,157 application, or P87C51X2BBD,157 equivalent, key selection criteria include OTP memory security (3-bit), programmable clock-out on P1.0, dual data pointers, 4 interrupt priority levels, and compatibility with legacy 80C51 toolchains and PCB layouts using LQFP-44 footprint SOT389-1.
Technical Context
This device implements a static CMOS 80C51 core with accelerated instruction execution via selectable 6-/12-clock architecture - enabling deterministic timing control and zero-frequency stop capability. Its oscillator supports crystal/resonator or external clock input, with CKCON register bit X2 allowing runtime clock mode switching without reset.
The MCU integrates standard 80C51 peripherals - including T0/T1 (standard), T2 (enhanced capture/compare), UART with framing error detection and address recognition - plus OTP-specific features like ROM security bits and LPEP analog power gating for sub-4 V operation. All I/O ports feature internal pull-ups and configurable alternate functions per pin.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | 80C51-compatible 8-bit CPU with Boolean processor and static design enabling 0 Hz operation |
| Memory | 4 KB on-chip OTP ROM + 128 B RAM; supports up to 64 KB external program/data memory addressing |
| Operating Voltage | 2.7 V to 5.5 V - enables single-supply battery or industrial rail operation without level-shifting |
| Max Clock Frequency | 33 MHz at 5 V (12-clock mode); 30 MHz at 5 V (6-clock mode); 16 MHz across full voltage range |
| Power Modes | Idle mode (CPU halted, peripherals active); Power-down mode (oscillator stopped, RAM retained down to 2.0 V) |
| I/O & Peripherals | 32 bidirectional I/O pins across four ports; three 16-bit timers; full-duplex UART with auto-address recognition |
| Security & Configuration | 3-bit OTP security lock; programmable clock-out on P1.0; CKCON.X2 bit for runtime 6/12-clock mode switch |
Pinout & Package
Package: Plastic low-profile quad flat package (LQFP), 44 leads, body size 10 × 10 × 1.4 mm (SOT389-1), commercial temperature range (0 °C to +70 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| P0.0–P0.7 | Open-drain bidirectional I/O / AD0–AD7 | Multiplexed address/data bus for external memory access; requires external pull-ups in open-drain mode |
| P1.0/T2 | General I/O / Timer2 external count input | Configurable as clock-out pin (50% duty cycle, 61 Hz–4 MHz) when T2 is set as generator |
| P1.1/T2EX | General I/O / Timer2 reload/capture control | Enables capture, reload, or direction control of Timer2 in enhanced modes |
| P2.0–P2.7 | Bidirectional I/O / A8–A15 | Provides high-order address byte during 16-bit external memory accesses |
| P3.0/RxD | Serial input | UART receive pin supporting multi-processor communication and full-duplex operation |
| P3.1/TxD | Serial output | UART transmit pin with framing error detection and automatic address recognition |
| P3.2/INT0 | External interrupt 0 input | Level-sensitive or edge-triggered interrupt source with dedicated priority level |
| P3.4/T0 & P3.5/T1 | Timer0/Timer1 external inputs | Enable external event counting or gated timer operation independent of system clock |
| RST | Active-high reset input | Requires ≥2 machine cycles high (24/12 oscillator periods) while oscillator runs; internal weak pull-down |
| XTAL1/XTAL2 | Oscillator input/output | Supports crystal (1–33 MHz), ceramic resonator, or external clock drive on XTAL1 only |
| EA/VPP | External access enable / programming voltage | High = execute from internal OTP; low = fetch from external memory below 0FFFH; 12.75 V for OTP programming |
| ALE/PROG | Address latch enable / programming pulse | Outputs 1/6 (12-clock) or 1/3 (6-clock) oscillator frequency; disabled via AUXR.0 bit |
| PSEN | External program store enable | Strobe for external ROM reads; inactive during internal code execution |
| VCC / VSS | Power supply / ground | Single 2.7–5.5 V supply; decoupling required near VCC pin for noise immunity |
Key Features
| Feature | Design Value |
|---|---|
| 6-/12-clock mode selectability | Runtime switch via CKCON.X2 bit - doubles or halves instruction throughput without hardware change |
| Programmable clock-out on P1.0 | Generates precise 50% duty-cycle clock (61 Hz–4 MHz @ 16 MHz osc.) for synchronizing external logic or ADC sampling |
| Dual Data Pointer (DPTR) | Enables efficient table lookups and string operations by eliminating DPTR reload overhead in memory transfers |
| Four-level nested interrupt priority | Allows deterministic real-time response to critical events (e.g., INT0 for emergency shutdown) while servicing lower-priority tasks |
| OTP security bits (3-bit) | Prevents unauthorized readout of firmware by locking OTP array - essential for IP protection in production devices |
| Low-power EPROM operation (LPEP) | AUXR.4 bit disables unused analog circuits below 4 V, reducing ICC by ~20% in battery-powered applications |
Applications
| Industrial PLC I/O Module | Legacy Equipment Controller |
|---|---|
Use Scenario: Standalone digital I/O expansion node in factory automation, interfacing with sensors, relays, and HMI panels via RS-485. IC Role / Device Role / Timing Role: Primary controller executing ladder logic scan, managing UART-based Modbus RTU protocol, and driving 32 discrete outputs with precise timing. Use Value: 4 KB OTP ensures field-upgradeable firmware without external memory; 128 B RAM suffices for real-time process variables; LQFP-44 simplifies rework on dense industrial PCBs. |
Use Scenario: Drop-in replacement for obsolete 8051-based controllers in medical infusion pumps, HVAC controllers, and test equipment. IC Role / Device Role / Timing Role: Pin- and code-compatible upgrade path preserving existing 80C51 assembly/C firmware, boot loader, and debug infrastructure. Use Value: Identical instruction timing and peripheral register map ensure zero-software-change migration; OTP eliminates EPROM UV erasure logistics. |
| Embedded Instrumentation Front-End | Low-Power Sensor Node |
Use Scenario: Signal conditioning and local display driver in portable multimeters, data loggers, and handheld analyzers. IC Role / Device Role / Timing Role: Manages LCD segment drivers, ADC interface (via external SPI), keypad scanning, and serial telemetry reporting. Use Value: Full-duplex UART with address recognition enables multi-drop sensor networks; 32 I/O lines support direct LED/LCD drive without glue logic. |
Use Scenario: Battery-operated environmental monitor collecting temperature/humidity data and transmitting via UART-to-LoRa bridge. IC Role / Device Role / Timing Role: Sleep-wake coordinator - uses power-down mode between readings, wakes on timer or external interrupt to sample and transmit. Use Value: Power-down current < 10 µA (typ.) extends CR2032 life >5 years; 2.7 V min operation avoids brown-out resets in aging batteries. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| P87C51FA,157 | Same core and OTP size but PLCC-44 package (SOT187-2) and extended temperature range (–40 °C to +85 °C) | Suitable for automotive or outdoor industrial environments requiring wider thermal stability | Select when board layout accommodates PLCC and ambient temperature exceeds +70 °C |
| P80C51BN,157 | ROM version (not OTP) in DIP-40 package (SOT129-1); identical 4 KB ROM, 128 B RAM, and 32 I/O | Used where firmware is fixed at manufacture and through-hole assembly is preferred | Select for cost-sensitive, high-volume consumer products with no field update requirement |
Compared with P87C51FA,157 and P80C51BN,157, the P87C51X2BBD,157 offers optimal trade-off between surface-mount density (LQFP-44), field-programmable OTP flexibility, and commercial-temperature reliability - making it ideal for space-constrained, firmware-upgradable embedded systems.
Availability
P87C51X2BBD,157 is available at Aetrix Electronics and suitable for industrial control systems, legacy equipment modernization, embedded instrumentation, and low-power sensor nodes requiring stable component supply and long-term lifecycle support.
Supply support for P87C51X2BBD,157 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
Philips Semiconductors (now NXP Semiconductors) is a pioneer in 8-bit microcontroller technology, delivering high-reliability, pin-compatible silicon for industrial and embedded markets since the 1980s.
The P87C51X2 series was designed specifically as a drop-in OTP-enhanced successor to the original 8051, targeting applications needing firmware security, low-voltage operation, and seamless migration from ROM or EPROM variants.
FAQ
What is the maximum operating frequency of the P87C51X2BBD,157?
The P87C51X2BBD,157 supports up to 33 MHz in 12-clock mode at 5 V ±10%, and up to 30 MHz in 6-clock mode at the same supply. Across its full 2.7–5.5 V range, the maximum guaranteed frequency is 16 MHz - ensuring reliable operation in battery-powered or wide-input-voltage designs without derating.
Does the P87C51X2BBD,157 include on-chip flash or EEPROM memory?
No, the P87C51X2BBD,157 contains 4 KB of one-time-programmable (OTP) ROM, not flash or EEPROM. OTP allows a single firmware write during manufacturing or programming - providing non-volatile storage with higher density and lower cost than flash at the expense of field reprogrammability.
Can the P87C51X2BBD,157 operate from a 3.3 V supply?
Yes, the P87C51X2BBD,157 is fully specified for operation from 2.7 V to 5.5 V. At 3.3 V, it delivers up to 16 MHz maximum frequency in both 6- and 12-clock modes, and supports low-power EPROM operation (LPEP) to reduce current draw - making it compatible with modern 3.3 V system rails.
How many interrupt sources and priority levels does the P87C51X2BBD,157 support?
The P87C51X2BBD,157 provides six interrupt sources - INT0, INT1, Timer0, Timer1, Timer2, and Serial - with four programmable priority levels. This enables hierarchical real-time response, such as assigning highest priority to emergency stop (INT0) and lowest to UART receive, without software polling.
Is the P87C51X2BBD,157 pin-compatible with other members of the P87C5xX2 family?
Yes - all P87C5xX2 variants (P87C51X2, P87C52X2, P87C54X2, P87C58X2) share identical pinouts across the same package type. The P87C51X2BBD,157 in LQFP-44 is pin-compatible with P87C52X2BBD,157 and P87C54X2BBD,157, enabling hardware reuse when upgrading ROM/OTP capacity or RAM size.
P87C51X2BBD,157 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Package/Case:
- 44-LQFP
- Series:
- 87C
- Packaging:
- Tray
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Core Processor:
- 8051
- Core Size:
- 8-Bit
- Speed:
- 33MHz
- Connectivity:
- EBI/EMI, UART/USART
- Peripherals:
- POR
- Number of I/O:
- 32
- Program Memory Size:
- 4KB (4K x 8)
- Program Memory Type:
- OTP
- EEPROM Size:
- -
- RAM Size:
- 128 x 8
- Voltage - Supply (Vcc/Vdd):
- 2.7V ~ 5.5V
- Data Converters:
- -
- Oscillator Type:
- Internal
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
P87C51X2BBD,157 FAQ
1.How can I place an order for P87C51X2BBD,157 through Aetrix?
Please submit a Request for Quotation (RFQ) for P87C51X2BBD,157 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 P87C51X2BBD,157 reliable?
The price and inventory of P87C51X2BBD,157 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for P87C51X2BBD,157 is usually 5 days.
3.What payment methods are accepted for P87C51X2BBD,157?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for P87C51X2BBD,157 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for P87C51X2BBD,157?
P87C51X2BBD,157 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your P87C51X2BBD,157 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 P87C51X2BBD,157?
For technical support, including P87C51X2BBD,157 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your P87C51X2BBD,157 requirements.
6.How does Aetrix verify that P87C51X2BBD,157 is sourced from the original manufacturer or authorized distributors?
All P87C51X2BBD,157 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 P87C51X2BBD,157 meets industry standards.
7.What is the process for return or replacement of P87C51X2BBD,157?
All P87C51X2BBD,157 units undergo pre-shipment inspection (PSI). If there is an issue with P87C51X2BBD,157, 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 P87C51X2BBD,157 part is unused and in its original packaging.
Return procedure for P87C51X2BBD,157:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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