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Texas Instruments LM27964SQ-I/NOPB
- Part No.:
- LM27964SQ-I/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM27964SQ-I/NOPB.pdf
- Description:
- IC LED DRIVER RGLTR DIM 24WQFN
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LM27964SQ-I/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 channel across four main-display (D1A–D4A), two sub-display (D1B–D2B), and one keypad (DKEY) current sinks, with I²C-compatible 10kHz PWM brightness control, 0.2% current matching between sinks, and adaptive 1×/3/2× gain switching over 2.7V–5.5V input.
For engineers reviewing the LM27964SQ-I/NOPB datasheet, LM27964SQ-I/NOPB pinout, LM27964SQ-I/NOPB application, or LM27964SQ-I/NOPB equivalent, key selection considerations include its WQFN-24 package footprint, resistor-programmable current scaling via ISETA/ISETB/ISETK pins, independent bank-level dimming registers (A0h/B0h), and thermal headroom requirements for high-current LED configurations.
Technical Context
The LM27964SQ-I/NOPB implements an adaptive CMOS charge pump with automatic 1×/3/2× gain selection based on real-time forward voltage monitoring of active Dxx pins (excluding DKEY). Its internal regulation maintains POUT at ~4.6V in closed-loop mode while minimizing power loss by maximizing pass-mode operation across the 2.7V–5.5V input range.
Three independent current-sink banks-BankA (4×30mA), BankB (2×30mA), and DKEY (80mA)-are controlled via I²C interface (address 0x36) using dedicated registers (10h, A0h, B0h). BankA/B support 16-step PWM dimming at fixed 10kHz frequency (LM27964SQ-I variant), while DKEY uses 4-level analog scaling (100%/70%/40%/20%) without PWM.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7V to 5.5V - supports full Li-ion battery discharge curve without external LDO. |
| Max Total Output Current | 180mA - distributed as 120mA (BankA+B) + 60mA (DKEY); requires thermal derating above 85°C ambient. |
| LED Current Matching | 0.2% typical - ensures uniform luminance across multi-LED displays without binning. |
| PWM Frequency | 10kHz - eliminates audible noise in handheld devices while enabling flicker-free human vision perception. |
| Charge Pump Efficiency | 87% peak - achieved via adaptive gain switching and low ROUT (2.75Ω) minimizes heat generation. |
| I²C Address | 0x36 - enables multi-device bus sharing with standard pull-up resistor sizing per VIO level. |
| Current Set Accuracy | ±10% - determined by external RSET tolerance and 1.25V reference stability over temperature. |
Pinout & Package
LM27964SQ-I/NOPB is housed in a 4mm × 4mm × 0.8mm WQFN-24 package (TI package code RTW0024A) with exposed thermal pad (DAP) for enhanced PCB heat dissipation. Pin numbering follows standard quad layout with top-view orientation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (24) | Power Input | Accepts 2.7V–5.5V supply; feeds charge pump and internal logic; requires 2.2µF ceramic decoupling. |
| POUT (23) | Charge Pump Output | Regulated output node (typ. 4.6V); supplies all LED anodes; connects to flying caps C1/C2. |
| D1A–D4A (13–16) | Main Display Sinks | Four independent constant-current sinks (30mA max each); common-anode LED connection. |
| D1B–D2B (4–5) | Sub Display Sinks | Two independent constant-current sinks (30mA max each); separate brightness register (A0h). |
| DKEY (6) | Keypad Sink | Single 80mA sink with analog dimming (B0h register); no forward-voltage sensing. |
| ISETA (17), ISETB (3), ISETK (12) | Current Reference Inputs | Set full-scale current via external resistors: IDxx = 200×(1.25V/RSETA/B) or 800×(1.25V/RSETK). |
| SCL (1), SDIO (2), VIO (7) | I²C Interface | Standard bidirectional bus; VIO defines logic levels (1.8V–VIN); requires external pull-ups to VIO. |
| GND (9,10,18,DAP) | Ground Reference | Multiple ground connections including thermal pad; must be low-impedance plane for stable regulation. |
| NC (8,11) | No Connect | Unbonded pins; leave floating or tie to GND per layout best practice. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive 1×/3/2× Charge Pump | Switches gain automatically based on LED forward voltage to maximize efficiency across input range. |
| Independent Bank Control | Three separate enable/brightness registers (10h/A0h/B0h) allow simultaneous but distinct display and keypad lighting profiles. |
| 0.2% Current Matching | Guarantees consistent brightness across all LEDs in BankA/B without manual calibration or trimming. |
| Resistor-Programmable Full-Scale Current | Enables precise current setting per bank using standard 1% resistors - no factory programming required. |
| Thermal Shutdown Protection | Engages at TJ ≈170°C and releases at 165°C - prevents permanent damage during sustained high-current operation. |
Applications
| Mobile Phone Main Display Backlight | Mobile Phone Sub Display Backlight |
|---|---|
Use Scenario: Driving four parallel white LEDs behind a 3.5-inch TFT LCD panel in a dual-screen smartphone. IC Role / Device Role / Timing Role: Constant-current sink providing regulated 30mA per LED with synchronized 10kHz PWM dimming via I²C register A0h. Use Value: Eliminates need for discrete current-setting resistors and external PWM controllers, reducing BOM count by 5+ components. | Use Scenario: Powering two white LEDs for secondary status display (e.g., clock, notifications) on clamshell or slider phones. IC Role / Device Role / Timing Role: Independent current sink group (BankB) with separate brightness register enabling asynchronous dimming vs. main display. Use Value: Enables always-on low-power sub-display operation while main screen is off, extending standby time. |
| Mobile Keypad LED Illumination | PDA Frontlight System |
Use Scenario: Supplying uniform 5mA to 16 individual keypad LEDs with analog brightness scaling. IC Role / Device Role / Timing Role: Dedicated DKEY sink with 4-level analog dimming (B0h register) and no PWM-induced EMI. Use Value: Reduces conducted emissions compared to PWM-driven keypad solutions, easing EMC compliance. | Use Scenario: Providing adjustable frontlight for monochrome or color e-ink displays in portable data terminals. IC Role / Device Role / Timing Role: Dual-bank driver powering both frontlight LEDs and auxiliary indicator LEDs from single IC. Use Value: Consolidates lighting functions into one WQFN-24 footprint, freeing PCB area for larger battery or RF modules. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar white LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3530UMX/NOPB | Supports 6-channel PWM dimming (up to 30mA/channel) with 8-bit resolution; lacks dedicated keypad sink; uses same WQFN-24 package. | Requires external current-setting for keypad LEDs; better suited for single-display systems needing higher dimming granularity. | Select when >16 brightness steps are required for main display and keypad drive is handled separately. |
| TPS61165DRVR | Boost-based architecture (not charge-pump); 40V output capability; single 30mA sink; smaller 6-pin SOT-23 package. | Designed for single high-Vf LED strings (e.g., RGB); incompatible with multi-sink dual-display topology. | Select only for cost-sensitive single-LED applications where inductor size is acceptable and dual-bank control is unnecessary. |
Compared with LM3530UMX/NOPB, LM27964SQ-I/NOPB provides integrated keypad drive and tighter current matching; versus TPS61165DRVR, it offers multi-sink architecture and inductorless operation critical for space-constrained mobile designs.
Availability
LM27964SQ-I/NOPB is available at Aetrix Electronics and suitable for mobile phone display backlighting, keypad LED illumination, and PDA frontlight systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM27964SQ-I/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 and interface solutions for portable electronics.
The LM27964SQ-I/NOPB belongs to TI's white LED driver product line, designed specifically for space-constrained mobile platforms requiring efficient, multi-bank, I²C-controlled backlighting with minimal external components.
FAQ
What is the maximum LED forward voltage supported by LM27964SQ-I/NOPB in 1× mode?
The LM27964SQ-I/NOPB supports up to ~3.6V LED forward voltage in 1× mode when VIN ≥ 3.6V. Below that threshold, the device automatically switches to 3/2× gain to maintain current regulation. This transition occurs when any active Dxx pin voltage drops to ~375mV, ensuring headroom remains sufficient for the 12mV/mA current sink requirement.
How do I configure LM27964SQ-I/NOPB to drive a single high-current LED using parallel outputs?
To drive one LED at 60mA using BankA, connect D1A–D4A together and set RSETA so each sink delivers 15mA (i.e., RSETA = 200 × 1.25V / 15mA ≈ 16.7kΩ). The LM27964SQ-I/NOPB treats parallel-connected outputs as a single load - no firmware changes needed beyond enabling ENA in register 10h and setting full-scale brightness in A0h.
Does LM27964SQ-I/NOPB require external capacitors, and what are the recommended values?
Yes, LM27964SQ-I/NOPB requires four external MLCCs: CIN and COUT (2.2µF each, X5R/X7R, 6.3V rating), and flying capacitors C1/C2 (1.0µF each, X5R/X7R, 6.3V rating). These values are validated in TI's SNOSAL6D datasheet for stable 10kHz PWM operation and <1% output ripple under full load.
Can LM27964SQ-I/NOPB operate with a 1.8V I²C bus voltage?
Yes, LM27964SQ-I/NOPB supports VIO from 1.8V to VIN. When VIO = 1.8V, logic thresholds become VIH = 1.31V and VIL = 0.49V per datasheet section "I²C Compatible Interface Voltage Specifications". Ensure external pull-ups connect to VIO (not VIN) and meet VOL ≤ 400mV at 2mA sink current.
What thermal design guidance applies to LM27964SQ-I/NOPB at 180mA total output?
At 180mA total output, LM27964SQ-I/NOPB dissipates ~0.5W (based on 87% efficiency at 3.6V input). With θJA = 41.3°C/W, junction temperature rise is ~21°C above ambient. To stay within 100°C TJ limit at 85°C ambient, use ≥200mm² copper pour under the DAP pad and minimize trace resistance to GND - TI AN-1187 provides verified layout examples.
LM27964SQ-I/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)
LM27964SQ-I/NOPB FAQ
1.How can I place an order for LM27964SQ-I/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM27964SQ-I/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 LM27964SQ-I/NOPB reliable?
The price and inventory of LM27964SQ-I/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM27964SQ-I/NOPB is usually 5 days.
3.What payment methods are accepted for LM27964SQ-I/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM27964SQ-I/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM27964SQ-I/NOPB?
LM27964SQ-I/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM27964SQ-I/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 LM27964SQ-I/NOPB?
For technical support, including LM27964SQ-I/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM27964SQ-I/NOPB requirements.
6.How does Aetrix verify that LM27964SQ-I/NOPB is sourced from the original manufacturer or authorized distributors?
All LM27964SQ-I/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 LM27964SQ-I/NOPB meets industry standards.
7.What is the process for return or replacement of LM27964SQ-I/NOPB?
All LM27964SQ-I/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM27964SQ-I/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 LM27964SQ-I/NOPB part is unused and in its original packaging.
Return procedure for LM27964SQ-I/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM27964SQ-I/NOPB Tags
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