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NXP Semiconductors PCF8551BTT/AJ
- Part No.:
- PCF8551BTT/AJ
- Manufacturer:
- NXP Semiconductors
- Category:
- Display Drivers
- Package:
- 48-TFSOP (0.240", 6.10mm Width)
- Datasheet:
-
PCF8551BTT/AJ.pdf
- Description:
- IC DRVR 7 SEGMENT 48TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,002
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Product details
Overview
PCF8551BTT/AJ from NXP Semiconductors is an ultra low-power SPI-interface LCD segment driver with 4 backplane and 36 segment outputs, operating from 1.8 V to 5.5 V on both VLCD and VDD supplies, supporting static to 1:4 multiplex drive modes, and designed for battery-operated metering and healthcare displays.
For engineers reviewing the PCF8551BTT/AJ datasheet, PCF8551BTT/AJ pinout, PCF8551BTT/AJ application, or PCF8551BTT/AJ equivalent, key selection factors include its TSSOP48 package, 5 MHz SPI interface, independent VLCD/VDD supplies, selectable 1/2 or 1/3 bias, and integrated LCD bias generation - all critical for low-power, space-constrained embedded LCD systems.
Technical Context
The PCF8551BTT/AJ implements a dedicated SPI-bus controller (not I²C), supports auto-incrementing display register writes across 128 bytes of RAM, and uses an internal oscillator configurable from 32 Hz to 128 Hz frame rate. Its display controller handles multiplexed waveform generation with frame or line inversion to eliminate DC bias.
Pin-level functionality includes CE (active-low chip enable), SDIO (bidirectional serial data), CLK (oscillator output/external clock input), and PORE (power-on reset enable). The device maintains register state in power-down mode and requires explicit DE bit assertion to activate display output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Interface | SPI-bus, 5 MHz max clock - enables deterministic timing and reduced pin count vs I²C in resource-constrained microcontroller systems. |
| Segment/Backplane Count | 36 segment drivers + 4 backplane outputs - supports up to 144-segment displays (e.g., 18×7-seg digits or 9×14-seg alphanumerics). |
| Supply Range | VDD and VLCD: 1.8 V to 5.5 V - allows single-supply operation and compatibility with Li-ion, coin-cell, or regulated 3.3 V/5 V rails. |
| Drive Modes | Static, 1:2, 1:3, or 1:4 multiplex - selectable via MUX[1:0] bits to match LCD glass configuration without external components. |
| Bias Configuration | 1/2 or 1/3 bias - configured by B bit; determines RMS voltage ratios (e.g., 1:4/1/3 yields Von/Voff = 1.732) for optimal contrast. |
| Operating Temperature | –40 °C to +85 °C - qualified for industrial and consumer medical equipment environments. |
| Blink Frequency | 0.5 Hz, 1 Hz, or 2 Hz - programmable via BL[1:0]; derived from frame clock, enabling user-alert visual feedback without host CPU overhead. |
Pinout & Package
TSSOP48 package (SOT362-1), plastic thin shrink small outline, 48 leads, body width 6.1 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SEG0–SEG35 | LCD segment output | 36 dedicated CMOS outputs driving LCD segments; each sinks/source current per bias mode and VLCD setting. |
| COM0–COM3 | LCD backplane output | 4 complementary outputs generating multiplexed backplane waveforms synchronized to segment data. |
| VLCD | LCD supply voltage | Independent analog supply rail (1.8–5.5 V); sets full-scale LCD drive voltage and directly impacts contrast and threshold margin. |
| VDD | Digital supply voltage | Core logic supply (1.8–5.5 V); powers SPI interface, registers, and control logic - decoupled from VLCD for noise isolation. |
| VSS | Ground reference | Common return for digital and analog sections; requires low-impedance connection to minimize display crosstalk and ripple. |
| CE | Chip enable input | Active-low enable for SPI communication; must be asserted before SCL/SDIO activity; disables internal logic when deasserted. |
| CLK | Oscillator I/O | Configurable as internal oscillator output (50% duty) or external clock input; left open if internal oscillator used and clock not needed externally. |
| SCL | SPI clock input | Master-generated clock synchronizing all SPI transfers; maximum 5 MHz operation defines minimum instruction latency. |
| SDIO | Serial data I/O | Bidirectional SPI data line; carries address byte followed by display/data register writes with auto-increment addressing. |
| PORE | Power-On Reset enable | Connect to VDD to enable internal POR (resets registers to default 1:4/1/3 bias); connect to VSS to disable and require software reset. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated LCD bias generator | On-chip fractional voltage divider with buffers delivers precise 1/2 or 1/3 bias levels to COM/SEG outputs - eliminates external resistors and reduces layout sensitivity. |
| Auto-incrementing display RAM access | After initial address byte, consecutive data bytes write to sequential registers (04h–17h) - simplifies firmware for full-display updates with minimal bus transactions. |
| Voltage-isolated VLCD and VDD supplies | Separate analog (VLCD) and digital (VDD) rails allow independent optimization: e.g., 3.3 V logic with 4.5 V VLCD for higher contrast in low-temp operation. |
| Programmable frame frequency | 32/64/96/128 Hz selectable via FF[1:0] - balances flicker suppression, power consumption, and response time for specific LCD glass characteristics. |
| Enhanced power drive mode (BOOST) | Enables higher segment drive current for large-capacitance displays (e.g., >100 nF total load) - increases VLCD current draw but prevents dimming or ghosting. |
Applications
| Metering Equipment | Consumer Healthcare Devices |
|---|---|
Use Scenario: Digital electricity/water/gas meters with multi-digit LCD readouts requiring long battery life and reliable segment activation under variable temperature. IC Role / Device Role / Timing Role: Primary LCD segment driver managing 4-backplane, 36-segment glass; generates multiplexed waveforms and bias voltages autonomously. Use Value: Ultra-low quiescent current and wide VLCD/VDD range extend coin-cell lifetime beyond 10 years while maintaining readability at –25 °C. |
Use Scenario: Portable blood glucose monitors and digital thermometers using 7- or 14-segment LCDs with backlight-independent visibility. IC Role / Device Role / Timing Role: Standalone display controller handling blinking alerts, digit updates, and contrast optimization without MCU intervention. Use Value: Integrated bias generation and frame-rate tuning ensure consistent contrast across 1.8–5.5 V supply drop during battery discharge. |
| Battery-Operated Industrial Sensors | Portable Test & Measurement Tools |
Use Scenario: Handheld environmental sensors (CO₂, humidity, pressure) with segmented LCDs operating on AA/AAA cells in field deployments. IC Role / Device Role / Timing Role: Low-power segment driver interfacing via SPI to ultra-low-power MCU; manages display enable/disable and blink states. Use Value: Power-down mode retains register state while drawing <1 µA, enabling instant wake-up and display restoration after sensor reading. |
Use Scenario: Pocket-sized multimeters and LCR meters requiring high-segment-count displays (e.g., 18-digit 7-seg) with clear digit separation. IC Role / Device Role / Timing Role: Segment driver configured in 1:4 multiplex mode with 1/3 bias to drive 144-element glass using minimal PCB real estate. Use Value: TSSOP48 footprint and SPI interface reduce board area vs parallel drivers; BOOST mode ensures sharp segment edges on high-capacitance glass. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LCD segment driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| PCF8551ATT/AJ | I²C interface (400 kHz), identical pinout and register map; lacks CE pin, uses SDA/SCL instead of SDIO/CE. | Preferred where MCU has limited GPIO but robust I²C peripheral; incompatible with SPI-only hosts. | Select PCF8551ATT/AJ only if system architecture mandates I²C and clock stretching tolerance is acceptable. |
| PCF8576CTT/AJ | Higher segment count (48 seg × 4 backplane), same TSSOP48 package, SPI interface, extended –40 °C to +105 °C rating. | Supports larger displays (e.g., 24-digit numeric or graphic panels); requires updated firmware for 48-seg RAM mapping. | Choose PCF8576CTT/AJ when future display expansion or extended temperature operation is required; pin-compatible but not register-compatible. |
Compared with PCF8551BTT/AJ, PCF8551ATT/AJ offers I²C convenience at the cost of lower speed and no chip-select granularity, while PCF8576CTT/AJ provides scalability and ruggedness at the expense of firmware adaptation - making PCF8551BTT/AJ optimal for cost-sensitive, SPI-based 144-segment designs.
Availability
PCF8551BTT/AJ is available at Aetrix Electronics and suitable for metering equipment, consumer healthcare devices, and battery-operated industrial sensors requiring stable component supply and long-term lifecycle support.
Supply support for PCF8551BTT/AJ 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 focused on secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in mixed-signal and display interface ICs.
The PCF8551 product line delivers ultra-low-power, integrated LCD drivers targeting battery-powered instrumentation and portable medical devices - emphasizing ease of integration, supply flexibility, and long-term reliability.
FAQ
What interface does the PCF8551BTT/AJ use, and how does it differ from the PCF8551ATT/AJ?
The PCF8551BTT/AJ uses a 5 MHz SPI-bus interface with CE, SCL, and bidirectional SDIO pins, enabling faster, deterministic communication than the I²C-based PCF8551ATT/AJ. Unlike the ATT variant, the BTT version requires active chip enable control and supports higher throughput for rapid display updates - critical in dynamic measurement instruments where latency matters.
Can the PCF8551BTT/AJ drive a 14-segment alphanumeric display, and how many characters fit?
Yes, the PCF8551BTT/AJ can drive up to nine 14-segment alphanumeric characters (including decimal point and accent dot), totaling 144 segments. Each character consumes 16 segment elements, and the device's 36 segment outputs are mapped across four backplanes to achieve this density - verified in Table 10 and Section 8 of the datasheet.
How does the PCF8551BTT/AJ handle power supply separation between VLCD and VDD?
The PCF8551BTT/AJ features physically isolated VLCD and VDD supply inputs, each rated 1.8 V to 5.5 V. This allows independent optimization - for example, using 3.3 V for logic (VDD) while applying 4.5 V to VLCD to boost contrast in low-temperature operation - without coupling noise or compromising display fidelity.
What happens to display memory and configuration registers during power-down mode on the PCF8551BTT/AJ?
In power-down mode (DE = 0), the PCF8551BTT/AJ disables the internal oscillator and halts display output, but retains all register contents including display RAM, address pointer, and control bits. The SPI interface remains active, allowing immediate reconfiguration and display enablement without reload - essential for low-duty-cycle sensor readouts.
Is the PCF8551BTT/AJ pin-compatible with other members of the PCF8551 family, such as the PCF8551BTT/A?
Yes, the PCF8551BTT/AJ shares identical TSSOP48 pinout and electrical characteristics with PCF8551BTT/A and PCF8551BTT/AY, differing only in packaging specification (NDP vs DP reel) and date code. All BTT variants use the same pin configuration shown in Figure 4 and Table 3, ensuring direct PCB compatibility across revisions.
PCF8551BTT/AJ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 48-TFSOP (0.240", 6.10mm Width)
- Packaging:
- Cut Tape (CT)
- Product Status:
- Obsolete
- Display Type:
- LCD
- Configuration:
- 7 Segment + DP, 14 Segment + DP + AP, Dot Matrix
- Interface:
- SPI
- Digits or Characters:
- 9 Characters, 18 Characters, 144 Elements
- Current - Supply:
- 1.2 µA
- Voltage - Supply:
- 1.8V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 48-TSSOP
PCF8551BTT/AJ FAQ
1.How can I place an order for PCF8551BTT/AJ through Aetrix?
Please submit a Request for Quotation (RFQ) for PCF8551BTT/AJ 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 PCF8551BTT/AJ reliable?
The price and inventory of PCF8551BTT/AJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PCF8551BTT/AJ is usually 5 days.
3.What payment methods are accepted for PCF8551BTT/AJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PCF8551BTT/AJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PCF8551BTT/AJ?
PCF8551BTT/AJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PCF8551BTT/AJ 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 PCF8551BTT/AJ?
For technical support, including PCF8551BTT/AJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PCF8551BTT/AJ requirements.
6.How does Aetrix verify that PCF8551BTT/AJ is sourced from the original manufacturer or authorized distributors?
All PCF8551BTT/AJ 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 PCF8551BTT/AJ meets industry standards.
7.What is the process for return or replacement of PCF8551BTT/AJ?
All PCF8551BTT/AJ units undergo pre-shipment inspection (PSI). If there is an issue with PCF8551BTT/AJ, 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 PCF8551BTT/AJ part is unused and in its original packaging.
Return procedure for PCF8551BTT/AJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
PCF8551BTT/AJ Tags
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PCA8561AHN/AY
NXP Semiconductors
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SN74LS47N
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PCF85176T/1Y
NXP Semiconductors
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PCF85176H/1,518
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BU9796AMUV-E2
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PCA85176H/Q900/1,5
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PCF8537AH/1,518
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LM3914VX/NOPB
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PCF85134HL/1,118
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AS1115-BSST
ams-OSRAM USA INC.
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LM3914V/NOPB
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