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Texas Instruments LM27964SQX-C/NOPB
- Part No.:
- LM27964SQX-C/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM27964SQX-C/NOPB.pdf
- Description:
- IC LED DRV RGLTR I2C 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,650
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Product details
Overview
LM27964SQX-C/NOPB from Texas Instruments is a charge-pump white LED driver IC optimized for dual-display mobile backlighting and keypad illumination. It delivers up to 30mA per LED across four Group A outputs (main LCD), 30mA per LED across two Group B outputs (sub LCD), and 80mA total to keypad LEDs, with I²C-compatible 23kHz PWM brightness control, 0.2% current matching between sinks, and adaptive 1×/3/2× charge pump operation from 2.7V–5.5V input.
For engineers reviewing the LM27964SQX-C/NOPB datasheet, LM27964SQX-C/NOPB pinout, LM27964SQX-C/NOPB application, or LM27964SQX-C/NOPB equivalent, this page provides verified technical context, exact pin functions, real-world current-setting resistor relationships, confirmed thermal headroom requirements, and validated alternative options for display lighting designs requiring precise multi-bank LED current regulation.
Technical Context
The LM27964SQX-C/NOPB implements an adaptive CMOS charge pump that dynamically selects 1× (pass-through) or 3/2× gain based on forward voltage monitoring of active Dxx pins-ensuring optimal efficiency across 2.7V–5.5V input while maintaining regulation. It uses internal amplifiers to hold ISETA/B/K at 1.25V (typ.), enabling external resistor programming of full-scale currents via IDxA/B = 200 × (1.25V / RSETA/B) and IDKEY = 800 × (1.25V / RSETK).
Its I²C interface operates at standard-mode speeds with fixed 36h slave address, supporting independent enable/disable and 16-level PWM dimming (Group A/B) plus 4-level analog scaling (DKEY). Gain transition occurs when any monitored Dxx pin voltage falls to 375mV (typ.), guaranteeing ≥180mV headroom for current regulation at full scale under worst-case conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7V to 5.5V - supports full Li-ion battery range without external LDO pre-regulation |
| Max Total Output Current | 180mA - distributed as ≤30mA per DxA/DxB pin and ≤80mA total on DKEY |
| LED Current Matching | 0.2% typ. - ensures uniform brightness across main/sub displays without binning |
| PWM Frequency (Group A/B) | 23kHz - eliminates audible noise in portable devices and avoids camera rolling shutter artifacts |
| I²C Slave Address | 0x36 - enables coexistence with other I²C peripherals on same bus without address conflict |
| Charge Pump Output Resistance | 2.75Ω typ. - defines POUT droop under load; critical for calculating minimum VIN vs. VLED design margin |
| Current Source Headroom | 180mV min. at full scale - sets minimum (POUT – VLED) required to maintain regulation |
Pinout & Package
LM27964SQX-C/NOPB is housed in a 24-pin WQFN package (4mm × 4mm × 0.8mm, RTW0024A), with exposed thermal pad (DAP) connected to GND for enhanced power dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (24) | Power Input | Accepts 2.7V–5.5V supply; powers charge pump and logic; requires 2.2µF ceramic input capacitor |
| POUT (23) | Charge Pump Output | Regulated high-side rail for all LED current sinks; connects to flying capacitors C1/C2 |
| D1A–D4A (13–16), D1B–D2B (4–5), DKEY (6) | LED Anode Outputs | Constant-current sinks for common-anode LED configurations; each rated ≤30mA (A/B) or total ≤80mA (KEY) |
| ISETA (17), ISETB (3), ISETK (12) | Current Reference Inputs | Sink 1.25V reference current; set full-scale LED current via RSETA/B/K per ID = k × (1.25V/RSET) |
| SCL (1), SDIO (2), VIO (7) | I²C Interface | Standard-mode bus interface; VIO defines logic level (1.8V–VIN); pull-up required on SDIO |
| GND (9,10,18,DAP) | Ground Reference | Primary return path; DAP must be soldered to PCB ground plane for thermal performance |
| NC (8,11) | No Connect | Not internally bonded; must remain unconnected per TI design guidelines |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive 1×/3/2× Charge Pump | Switches gain automatically based on real-time Dxx pin voltage to maximize efficiency across input and LED Vf range |
| Independent Bank Control | Three enable bits (ENA/ENB/ENK) and separate brightness registers allow simultaneous but distinct dimming of main display, sub display, and keypad |
| High-Accuracy Current Matching | 0.2% typical matching within Group A and Group B ensures consistent luminance without optical compensation |
| Resistor-Programmable Full-Scale Current | RSETA/B set 200× scaling factor (e.g., 16.9kΩ → 15mA); RSETK sets 800× scaling (e.g., 16.9kΩ → 60mA) |
| 23kHz PWM Dimming (SQ-C variant) | Fixed-frequency PWM eliminates low-frequency flicker and audible coil whine in compact handheld layouts |
Applications
| Main LCD Backlighting | Sub LCD Backlighting |
|---|---|
Use Scenario: Powering 4 parallel white LEDs behind a 3.5-inch TFT main display in a feature phone. IC Role / Device Role / Timing Role: Constant-current sink bank (Group A) with I²C-controlled 16-step PWM dimming and adaptive charge pump gain selection. Use Value: Delivers stable 30mA per LED across 2.7–4.2V battery discharge with <0.2% mismatch, eliminating visible brightness gradients. | Use Scenario: Driving 2 white LEDs for secondary status display in dual-screen clamshell phones. IC Role / Device Role / Timing Role: Independent constant-current sink bank (Group B), enabled/disabled and dimmed separately from Group A via I²C register writes. Use Value: Enables dynamic sub-display brightness scaling (e.g., dim during sleep mode) without affecting main display output or requiring additional drivers. |
| Keypad LED Illumination | Multi-Function Indicator Lighting |
Use Scenario: Supplying 5mA to 16 discrete keypad LEDs in a ruggedized industrial handset. IC Role / Device Role / Timing Role: Dedicated analog-scaled current sink (DKEY) with 4 fixed brightness levels (100%/70%/40%/20%) and 80mA total capability. Use Value: Eliminates need for individual current-limiting resistors per key; reduces BOM count and PCB area while ensuring uniform key visibility. | Use Scenario: Driving mixed-color indicator LEDs (red/green/blue) on a medical device front panel requiring precise intensity control. IC Role / Device Role / Timing Role: Flexible current sink resource where D1A–D4A are paralleled to drive higher-current single LEDs, and DKEY supplies auxiliary indicators. Use Value: Supports both high-brightness (30mA) and low-power (5–15mA) indicators from one IC, simplifying layout and reducing thermal hotspots. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar white LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM27965SQX/NOPB | Same pinout and register map; supports 10kHz or 23kHz PWM via suffix; no dedicated keypad driver - only two LED banks (4+2) | Lacks DKEY bank and ISETK/RSETK interface; requires external circuitry for keypad lighting | Select when keypad illumination is handled separately and dual-display current matching remains critical |
| TPS61165DRVR | Single-bank 30mA driver with integrated boost converter; no I²C interface - uses EN/CTRL pin for PWM dimming | Requires external MCU GPIO for brightness control; no multi-bank independence or keypad support | Select for cost-sensitive single-display systems where I²C bus loading or register-based control is unnecessary |
Compared with LM27964SQX-C/NOPB, LM27965SQX/NOPB retains identical dual-display functionality but removes keypad integration, while TPS61165DRVR trades programmability and multi-bank flexibility for simpler implementation and lower component count in single-output applications.
Availability
LM27964SQX-C/NOPB is available at Aetrix Electronics and suitable for mobile phone display lighting, PDA backlighting, and keypad LED illumination requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for LM27964SQX-C/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, embedded processing, and digital signal processing technologies, with leadership in power management and precision analog ICs.
The LM27964 belongs to TI's white LED driver product line, designed specifically for space-constrained portable electronics requiring high-efficiency, multi-bank, I²C-programmable backlight and indicator solutions.
FAQ
What is the PWM frequency of LM27964SQX-C/NOPB, and how does it differ from the LM27964SQ-I/NOPB?
The LM27964SQX-C/NOPB features a fixed 23kHz internal PWM frequency for Groups A and B, which suppresses audible noise and avoids interference with camera image sensors. In contrast, the LM27964SQ-I/NOPB uses 10kHz PWM. This distinction is hard-coded by silicon variant and cannot be changed via register settings or external components. Both variants share identical pinout, I²C interface, and current-setting architecture.
How do I calculate the RSET resistor values for LM27964SQX-C/NOPB to achieve 25mA per LED in Group A?
To set 25mA per LED in Group A using LM27964SQX-C/NOPB, use the formula IDxA = 200 × (1.25V / RSETA). Rearranged: RSETA = 200 × 1.25V / 25mA = 10kΩ. A standard 10.0kΩ ±1% resistor yields 25.0mA typical. Note that RSETB and RSETK follow the same principle but with scaling factors of 200 and 800 respectively, and must be placed individually between each ISET pin and GND.
Does LM27964SQX-C/NOPB support connecting multiple LEDs in parallel to a single DxA output?
Yes, LM27964SQX-C/NOPB allows paralleling D1A–D4A (or D1B–D2B) outputs to drive higher-current single LEDs. For example, connecting all four Group A outputs to one LED requires setting RSETA so each sink delivers 25% of target current (e.g., 15mA per sink for 60mA total). The IC maintains regulation and matching across paralleled paths, and all electrical specifications-including headroom and output resistance-apply identically to this configuration.
What is the minimum headroom voltage required at the Dxx pins for LM27964SQX-C/NOPB to maintain current regulation?
LM27964SQX-C/NOPB requires a minimum headroom voltage of 180mV across each active Dxx pin (i.e., VPOUT – VLEDx ≥ 180mV) to ensure proper current regulation at full scale. This value is derived from the typical headroom constant kHR = 12mV/mA applied to 30mA maximum sink current (12mV/mA × 30mA = 360mV), but the datasheet specifies 180mV as the guaranteed minimum under worst-case conditions including process and temperature variation.
Can LM27964SQX-C/NOPB operate with a 1.8V I²C bus while powered from a 3.6V supply?
Yes, LM27964SQX-C/NOPB supports mixed-voltage I²C operation: tie VIO to 1.8V to set logic thresholds, while VIN remains at 3.6V. The SCL and SDIO pins accept input voltages from 0V to (VIN + 0.3V), and VOL is specified at 400mV with 2mA load-compatible with 1.8V systems using appropriate pull-up resistors. This allows direct interfacing with low-voltage MCUs without level shifters.
LM27964SQX-C/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Switched Capacitor (Charge Pump)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 7
- Voltage - Supply (Min):
- 2.7V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 2V ~ 4V
- Current - Output / Channel:
- 30mA, 80mA
- Frequency:
- 700kHz
- Dimming:
- I2C
- Applications:
- Backlight
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (4x4)
LM27964SQX-C/NOPB FAQ
1.How can I place an order for LM27964SQX-C/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM27964SQX-C/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 LM27964SQX-C/NOPB reliable?
The price and inventory of LM27964SQX-C/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM27964SQX-C/NOPB is usually 5 days.
3.What payment methods are accepted for LM27964SQX-C/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM27964SQX-C/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM27964SQX-C/NOPB?
LM27964SQX-C/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM27964SQX-C/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 LM27964SQX-C/NOPB?
For technical support, including LM27964SQX-C/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM27964SQX-C/NOPB requirements.
6.How does Aetrix verify that LM27964SQX-C/NOPB is sourced from the original manufacturer or authorized distributors?
All LM27964SQX-C/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 LM27964SQX-C/NOPB meets industry standards.
7.What is the process for return or replacement of LM27964SQX-C/NOPB?
All LM27964SQX-C/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM27964SQX-C/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 LM27964SQX-C/NOPB part is unused and in its original packaging.
Return procedure for LM27964SQX-C/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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