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NXP Semiconductors PCA9956ATWY
- Part No.:
- PCA9956ATWY
- Manufacturer:
- NXP Semiconductors
- Category:
- LED Drivers
- Package:
- 38-TFSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
PCA9956ATWY.pdf
- Description:
- IC LED DRV LIN PWM 65MA 38HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,301
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Product details
Overview
PCA9956ATWY from NXP Semiconductors is a 24-channel I²C-bus constant-current LED driver optimized for RGBA LED dimming and blinking in amusement products. It delivers 57 mA per channel, supports 31.25 kHz individual PWM (256-step) and 122 Hz group PWM (256-step), operates from 3 V to 5.5 V, and tolerates up to 20 V LED supply voltage.
For engineers reviewing the PCA9956ATWY datasheet, PCA9956ATWY pinout, PCA9956ATWY application, or PCA9956ATWY equivalent, key selection criteria include its Fast-mode Plus (1 MHz) I²C interface, hardware address scalability (125 devices), thermal/short/open-load diagnostics, active-low OE for hardware blink control, and programmable group/sub-call addressing for synchronized multi-device effects.
Technical Context
The PCA9956ATWY integrates dual PWM architectures: independent 8-bit brightness control per channel at 31.25 kHz and shared 8-bit group dimming/blinking with frequency programmable from 15 Hz to 16.8 s. Its internal 8 MHz oscillator eliminates external timing components, and output current is set via REXT resistor with ±4% inter-channel accuracy.
It features four software-programmable I²C addresses (one All Call + three Sub Call), enabling hierarchical control of LED groups across multiple devices. Error detection registers report open/short load and overtemperature faults via I²C, while thermal shutdown protects against junction temperature exceedance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| LED Channels | 24 constant-current sink outputs, each programmable for off/on/PWM/brightness+group mix |
| Max Output Current | 57 mA per channel, adjustable from 225 µA to 57 mA via external REXT resistor |
| Individual PWM | 256-step (8-bit), fixed 31.25 kHz frequency, 0–99.6% duty cycle |
| Group PWM | 256-step (8-bit), frequency programmable 15 Hz to 16.8 s, 0–99.6% duty cycle |
| I²C Interface | Fast-mode Plus (Fm+) compliant, up to 1 MHz, 30 mA SDA drive strength for high-capacitance buses |
| Supply Range | VDD = 3.0 V to 5.5 V; LED supply up to 20 V; 5.5 V tolerant non-LED pins |
| Operating Temp | −40 °C to +85 °C ambient; integrated thermal shutdown and error flag reporting |
Pinout & Package
PCA9956ATWY is housed in a thermally enhanced HTSSOP38 package (SOT1331-1) with 38 leads, 0.5 mm pitch, 4.4 mm body width, and exposed thermal pad connected to VSS.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REXT (1) | Current reference input | Connects external resistor to ground to set full-scale output current (225 µA–57 mA) |
| AD0–AD2 (2–4) | Quinary address inputs | Each accepts GND/PD/FLT/PU/VDD for 125 unique hardware I²C slave addresses |
| OE (5) | Active-low output enable | Hardware blink/dim control; overrides all LED states when asserted |
| LED0–LED23 (6–13,15–20,22–24,26–33) | Constant-current LED sinks | 24 individually controllable outputs; tolerate 20 V when OFF |
| RESET (35) | Active-low reset input | Hardware reset that initializes registers to POR state (all LEDs OFF) |
| SCL/SDA (36/37) | I²C bus interface | Fm+ compatible; SDA has 30 mA drive capability for robust high-capacitance operation |
| VDD (38) | Power supply | 3.0–5.5 V digital/analog supply; powers internal oscillator and logic |
| VSS (14,18,21,25,34) | Ground | Multiple dedicated ground pins plus exposed thermal pad (connected to VSS) for thermal and EMI performance |
Key Features
| Feature | Design Value |
|---|---|
| 24-channel synchronized control | Enables marquee chasing, color-mixing, and uniform dimming across RGB/RGBA arrays without software overhead |
| Programmable LED output delay | Reduces inrush current and EMI by staggering turn-on timing across channels |
| On-chip diagnostics | Detects open-circuit, short-circuit, and overtemperature faults per channel; status readable via I²C error flag registers |
| Multi-level I²C addressing | Supports All Call (E0h), three Sub Call addresses, and 125 hardware-configurable slave addresses for scalable system design |
| Software Reset (SWRST) | Allows full register reinitialization over I²C-identical to power-on reset-enabling dynamic reconfiguration without hardware reset |
Applications
| Amusement Lighting Control | RGB Status Indication |
|---|---|
Use Scenario: Dynamic lighting in arcade cabinets, prize wheels, and interactive game panels requiring synchronized blinking, fading, and color transitions. IC Role / Device Role / Timing Role: Primary 24-channel LED driver managing individual RGBA brightness and group blink patterns via I²C. Use Value: Eliminates microcontroller PWM resource burden; enables smooth 31.25 kHz flicker-free dimming and independent 15 Hz–16.8 s blink timing per device group. | Use Scenario: Multi-color status indicators on industrial HMI panels, medical equipment, or network switches where red/green/amber states convey operational mode. IC Role / Device Role / Timing Role: Constant-current sink driver delivering precise 57 mA per LED with ±4% channel matching for consistent luminance. Use Value: Ensures uniform brightness across all status LEDs regardless of forward voltage variation; built-in open/short detection prevents false status reporting. |
| LED Display Backlighting | Keypad Illumination |
Use Scenario: Edge-lit or direct-lit backlight for small-format LCD displays in handheld gaming devices or portable test instruments. IC Role / Device Role / Timing Role: Group-dimming controller using GRPPWM/GRPFREQ registers to adjust overall display brightness smoothly. Use Value: Achieves 122 Hz base dimming with extended low-frequency blink capability (down to 15 Hz) for adaptive ambient light response without visible flicker. | Use Scenario: Uniform keypad backlighting in cellular phones or ruggedized handheld terminals where space and power efficiency are critical. IC Role / Device Role / Timing Role: Compact 24-channel driver powering multiple key LEDs from a single IC with minimal external components. Use Value: Reduces BOM count vs. discrete drivers; HTSSOP38 package with thermal pad ensures stable operation under continuous illumination. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 24-channel constant-current LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLC5947 | 24-channel, 12-bit PWM (4096 steps), 30 MHz SPI interface, no built-in open/short detection | Requires SPI host; lacks I²C group addressing and diagnostic registers | Preferred when higher grayscale resolution and faster update rates are needed, but diagnostic capability and I²C scalability are secondary |
| IS31FL3731 | 28-channel, 8-bit PWM, I²C interface, integrated auto-breathing, no REXT-based current adjustment | Fixed 25 mA max per channel; uses internal current DAC instead of external resistor | Chosen for compact LED matrix applications needing breathing effects and simpler layout, but not for 57 mA high-current RGBA setups |
Compared with TLC5947 and IS31FL3731, PCA9956ATWY uniquely combines 57 mA per channel, Fast-mode Plus I²C scalability (125 devices), hardware-addressed group control, and per-channel fault diagnostics-making it optimal for high-reliability amusement and industrial status lighting where current drive, bus robustness, and failure visibility are critical.
Availability
PCA9956ATWY is available at Aetrix Electronics and suitable for amusement lighting systems, RGB status indicators, LED display backlights, and keypad illumination requiring stable component supply and long-term production continuity.
Supply support for PCA9956ATWY 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 company specializing in secure connectivity solutions for automotive, industrial, and IoT applications.
The PCA9956ATWY belongs to NXP's LED driver product line, designed specifically for high-channel-count, high-current, and diagnostics-enabled LED control in entertainment and human-machine interface systems.
FAQ
What is the maximum LED supply voltage supported by the PCA9956ATWY?
The PCA9956ATWY LED outputs are rated to tolerate up to 20 V when in the OFF state. This allows direct connection to common 12 V or 19 V LED strings without additional voltage translation, provided the VDD supply remains within 3.0 V to 5.5 V. The 20 V rating applies to the LED sink terminals (LED0–LED23) and is independent of the logic supply rail.
How does the PCA9956ATWY achieve 125 unique I²C addresses?
The PCA9956ATWY uses three quinary address pins (AD0, AD1, AD2), each configurable in five states (GND, pull-down, floating, pull-up, VDD), yielding 5³ = 125 distinct hardware slave addresses. These are sampled once at power-up and latched internally; no further sampling occurs until the next power cycle. The PCA9956ATWY datasheet provides full mapping tables for all combinations.
Can the PCA9956ATWY drive LEDs with different forward voltages simultaneously?
Yes-the PCA9956ATWY is a constant-current sink driver, so each LED channel regulates current independently of forward voltage. As long as the LED anode supply voltage remains ≤20 V and exceeds the sum of the LED forward voltage plus the driver's compliance voltage (typically <2 V at 57 mA), mixed-Vf LEDs (e.g., red, green, blue) can be driven concurrently with matched brightness via individual PWM registers.
What diagnostic capabilities does the PCA9956ATWY provide?
The PCA9956ATWY integrates open-load, short-load, and overtemperature detection per channel. Fault status is reported in six read-only error flag registers (EFLAG0–EFLAG5), each covering four channels. These registers are accessible via I²C, enabling real-time health monitoring without external circuitry-critical for maintenance-free amusement and industrial applications.
Does the PCA9956ATWY require an external crystal or resonator?
No-the PCA9956ATWY contains an internal 8 MHz oscillator that requires no external components. This oscillator drives both the 31.25 kHz individual PWM and the 122 Hz group PWM clocks, as well as the I²C timing logic. The absence of external timing parts simplifies PCB layout and improves system reliability.
PCA9956ATWY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 38-TFSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Linear
- Topology:
- -
- Internal Switch(s):
- Yes
- Number of Outputs:
- 24
- Voltage - Supply (Min):
- 3V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- -
- Current - Output / Channel:
- 65mA
- Frequency:
- -
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 38-HTSSOP
PCA9956ATWY FAQ
1.How can I place an order for PCA9956ATWY through Aetrix?
Please submit a Request for Quotation (RFQ) for PCA9956ATWY 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 PCA9956ATWY reliable?
The price and inventory of PCA9956ATWY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PCA9956ATWY is usually 5 days.
3.What payment methods are accepted for PCA9956ATWY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PCA9956ATWY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PCA9956ATWY?
PCA9956ATWY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PCA9956ATWY 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 PCA9956ATWY?
For technical support, including PCA9956ATWY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PCA9956ATWY requirements.
6.How does Aetrix verify that PCA9956ATWY is sourced from the original manufacturer or authorized distributors?
All PCA9956ATWY 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 PCA9956ATWY meets industry standards.
7.What is the process for return or replacement of PCA9956ATWY?
All PCA9956ATWY units undergo pre-shipment inspection (PSI). If there is an issue with PCA9956ATWY, 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 PCA9956ATWY part is unused and in its original packaging.
Return procedure for PCA9956ATWY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
PCA9956ATWY Tags
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BCR402RE6327HTSA1
Infineon Technologies
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BCR430UXTSA2
Infineon Technologies
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BCR420UE6433HTMA1
Infineon Technologies
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BCR420UE6327HTSA1
Infineon Technologies
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BCR421UE6327HTSA1
Infineon Technologies
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LYT1604D-TL
Power Integrations
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HV9910CLG-G
Microchip Technology
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CL2N8-G
Microchip Technology
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BCR420UW6-7
Diodes Incorporated
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BCR421UW6-7
Diodes Incorporated
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BCR420UFD-7
Diodes Incorporated
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BCR421UFD-7
Diodes Incorporated
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