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Texas Instruments LP3943ISQ/NOPB
- Part No.:
- LP3943ISQ/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LP3943ISQ/NOPB.pdf
- Description:
- IC LED DRIVER PS I2C 25MA 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,742
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Product details
Overview
LP3943ISQ/NOPB from Texas Instruments is a 16-channel SMBus/I²C-controlled RGB and white-LED driver IC with independent per-channel dimming control, 25mA sink capability per output, internal precision oscillator (0.625Hz–160Hz dimming range), and programmable PWM frequency/duty cycle registers. It serves as a low-side LED current switch array in mobile handset indicator and flashlight subsystems.
For engineers reviewing the LP3943ISQ/NOPB datasheet, LP3943ISQ/NOPB pinout, LP3943ISQ/NOPB application, or LP3943ISQ/NOPB equivalent, key selection criteria include per-output dimming state control (ON/OFF/DIM0/DIM1), I²C slave address configurability via A0–A2 pins, thermal derating at 200mA package limit, and GPIO reuse capability for unused LED outputs.
Technical Context
The LP3943ISQ/NOPB integrates two independent 8-bit PWM registers (PWM0/PWM1) and two 8-bit prescaler registers (PSC0/PSC1), enabling dual dimming profiles across its 16 channels. Each LED output maps to one of four functional states-Hi-Z, active-low ON, DIM0, or DIM1-via dedicated selector registers (LS0–LS3).
It implements an internal oscillator eliminating external timing components, supports auto-increment I²C register access, and features active-low reset with 10ns minimum pulse width. The device operates from 2.3V to 5.5V, delivers up to 25mA per channel, and enforces 100mA per octal group (LED0–7 / LED8–15) and 200mA total package sink current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output channels | 16 independent open-drain LED drivers with per-pin state control |
| Sink current per pin | 25mA maximum - defines individual LED string current capability |
| Total package sink current | 200mA maximum - constrains simultaneous high-brightness operation across all channels |
| Dimming frequency range | 0.625Hz to 160Hz - sets blink/dim period resolution (6.25ms to 1.6s) |
| PWM resolution | 8-bit duty cycle control - enables 256-step brightness granularity per dim profile |
| Supply voltage range | 2.3V to 5.5V - compatible with Li-ion battery and 3.3V/5V system rails |
| I²C interface speed | 400kHz Fast Mode - determines maximum configuration update rate for multi-channel setups |
Pinout & Package
LP3943ISQ/NOPB uses a 24-pin WQFN (RTW) package with 4.00mm × 4.00mm body size and exposed thermal pad tied internally to GND.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| LED0–LED15 | Open-drain output | 16 low-side current switches - each sinks up to 25mA to drive LED cathodes |
| RST | Digital input | Active-low hardware reset - forces default register state and halts PWM operation |
| SCL / SDA | I²C bus interface | Standard bidirectional I²C communication - supports 400kHz Fast Mode with slave address set by A0–A2 |
| VDD | Power supply | Main supply input - powers internal logic, oscillator, and output drivers (2.3V–5.5V) |
| GND | Ground reference | Primary return path for all currents - connects to exposed pad for thermal conduction |
| A0–A2 | Address input | 3-bit I²C slave address select - enables up to 8 devices on same bus without address conflict |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent dimming profiles | Separate 8-bit PWM and prescaler registers (PSC0/PWM0 and PSC1/PWM1) allow concurrent 1Hz + 5Hz blinking on different LED groups |
| Per-output functional state control | Four-state selector bits (B1/B0) per LED enable precise assignment to Hi-Z, ON, DIM0, or DIM1 modes without software overhead |
| I²C auto-increment addressing | Reduces command overhead - sequential register writes require only one chip address and register pointer setup |
| GPIO expansion capability | Unused LEDx pins function as general-purpose open-drain I/O - supports button sensing or logic-level signaling |
| Internal oscillator | Eliminates external crystal/capacitor - ensures consistent dimming timing across temperature (-40°C to +85°C operating range) |
Applications
| Cellular Phone Indicator Lights | Digital Camera Status Lighting |
|---|---|
Use Scenario: Customizable multicolor notification lighting synchronized to call, message, or charging events. IC Role / Device Role / Timing Role: LED driver with independent per-channel dimming control and I²C-configurable blink patterns. Use Value: Reduces baseband processor I/O load and bus traffic versus shift-register alternatives - single I²C command activates preprogrammed LED sequences. |
Use Scenario: Power-on confirmation, recording status, and low-battery warning using RGB LEDs. IC Role / Device Role / Timing Role: Low-power, compact LED controller managing discrete red/green/blue elements with precise intensity control. Use Value: Enables smooth color transitions and variable blink rates using internal PWM timing - no host CPU intervention required after initial setup. |
| Portable Device Flashlight | Toys with Animated Lighting |
Use Scenario: White LED flashlight mode activated via single-button press in handheld electronics. IC Role / Device Role / Timing Role: High-current LED driver configured for uniform full-brightness output across multiple parallel strings. Use Value: Delivers up to 200mA total sink current - supports bright illumination while maintaining thermal safety within WQFN package limits. |
Use Scenario: Rhythmic color-shifting effects and pattern-based animations in consumer toys. IC Role / Device Role / Timing Role: Programmable LED sequencer with dual dimming profiles and reset-triggered pattern restart. Use Value: Internal oscillator ensures stable animation timing across battery voltage drop - eliminates need for external clock source. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLC59284RGER | 16-channel constant-current sink driver with 12-bit PWM, no internal oscillator - requires external clock or MCU timing | Higher PWM resolution but lacks autonomous dimming; better for precision brightness control where host timing is available | Select TLC59284RGER when >256-step grayscale is required and system provides accurate clock source |
| PCA9635D,118 | 16-channel I²C LED driver with 6-bit PWM, integrated oscillator, and open-drain outputs - max 25mA per channel, 100mA package limit | Lower PWM resolution and reduced package current rating - suitable for lower-power indicator use only | Choose PCA9635D,118 for cost-sensitive designs where 64-step dimming suffices and total LED current stays below 100mA |
Compared with TLC59284RGER and PCA9635D,118, the LP3943ISQ/NOPB uniquely balances autonomous dual-profile dimming, 200mA package current headroom, and 8-bit PWM resolution - making it optimal for battery-powered RGB indicator and flashlight subsystems requiring minimal host intervention.
Availability
LP3943ISQ/NOPB is available at Aetrix Electronics and suitable for cellular phone indicator systems, portable camera status lighting, and toy-based animated LED applications requiring stable component supply and long-term production continuity.
Supply support for LP3943ISQ/NOPB 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
Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in power management, signal chain, and interface solutions.
The LP3943ISQ/NOPB belongs to TI's LED driver product line, engineered specifically for low-power, multi-color indicator and flashlight functions in space-constrained portable electronics.
FAQ
What is the maximum sink current per channel for the LP3943ISQ/NOPB?
The LP3943ISQ/NOPB supports up to 25mA sink current per LED output pin. This value is specified under test conditions of VOL = 0.7V and VDD = 5V. Exceeding this limit risks thermal overstress or output degradation. The device also enforces 100mA per octal group (LED0–LED7 or LED8–LED15) and 200mA total package current - all must be observed simultaneously in design.
Does the LP3943ISQ/NOPB require an external clock source?
No, the LP3943ISQ/NOPB contains an internal precision oscillator that generates all timing signals required for PWM dimming and register operation. This eliminates the need for external crystals, RC networks, or MCU-generated clocks - simplifying layout and improving timing stability across temperature and voltage variations.
How many I²C addresses can be configured on the LP3943ISQ/NOPB?
The LP3943ISQ/NOPB supports eight unique I²C slave addresses via the A0, A1, and A2 address input pins. These pins accept static HIGH/LOW logic levels, allowing up to eight LP3943ISQ/NOPB devices to share the same I²C bus without address collision - essential for multi-display or modular lighting systems.
Can unused LED outputs on the LP3943ISQ/NOPB be used as general-purpose I/O?
Yes, any LEDx pin not assigned to drive an LED can be reconfigured as a general-purpose open-drain I/O. When set to Hi-Z state via the LS0–LS3 selector registers, the pin presents high impedance and may be used for input sensing (e.g., button detection) or wired-OR logic signaling - extending functionality without adding discrete GPIO expanders.
What thermal considerations apply to the LP3943ISQ/NOPB in continuous operation?
The LP3943ISQ/NOPB has a junction-to-board thermal resistance (RθJB) of 22.4°C/W and a maximum junction temperature of 125°C. At full 200mA package current and 5.5V supply, power dissipation approaches 400mW - requiring adequate PCB copper area under the exposed pad and proper airflow or ambient derating above 60°C to maintain reliability.
LP3943ISQ/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Power Switch
- Topology:
- Shift Register
- Internal Switch(s):
- Yes
- Number of Outputs:
- 16
- Voltage - Supply (Min):
- 2.3V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- -
- Current - Output / Channel:
- 25mA
- Frequency:
- -
- Dimming:
- I2C, SMBus
- Applications:
- Camera Flash
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (4x4)
LP3943ISQ/NOPB FAQ
1.How can I place an order for LP3943ISQ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP3943ISQ/NOPB 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 LP3943ISQ/NOPB reliable?
The price and inventory of LP3943ISQ/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP3943ISQ/NOPB is usually 5 days.
3.What payment methods are accepted for LP3943ISQ/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP3943ISQ/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP3943ISQ/NOPB?
LP3943ISQ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP3943ISQ/NOPB 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 LP3943ISQ/NOPB?
For technical support, including LP3943ISQ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP3943ISQ/NOPB requirements.
6.How does Aetrix verify that LP3943ISQ/NOPB is sourced from the original manufacturer or authorized distributors?
All LP3943ISQ/NOPB 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 LP3943ISQ/NOPB meets industry standards.
7.What is the process for return or replacement of LP3943ISQ/NOPB?
All LP3943ISQ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP3943ISQ/NOPB, 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 LP3943ISQ/NOPB part is unused and in its original packaging.
Return procedure for LP3943ISQ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LP3943ISQ/NOPB Tags
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BCR402RE6327HTSA1
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CL2N8-G
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BCR420UFD-7
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BCR421UFD-7
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