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Texas Instruments LM27964SQX-A/NOPB
- Part No.:
- LM27964SQX-A/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM27964SQX-A/NOPB.pdf
- Description:
- IC LED DRV RGLTR I2C 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,010
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Product details
Overview
LM27964SQX-A/NOPB from Texas Instruments is a charge-pump white LED driver IC designed for multi-display mobile backlighting. It delivers up to 30mA per LED across two independently controlled banks (4× main display + 2× sub display) and 80mA dedicated keypad drive, with 0.2% current matching, I²C-compatible 16-level PWM dimming (10kHz or 23kHz), and adaptive 1×/3/2× gain switching - used in dual-LCD smartphones requiring precise brightness control and high efficiency.
For engineers reviewing the LM27964SQX-A/NOPB datasheet, LM27964SQX-A/NOPB pinout, LM27964SQX-A/NOPB application, or LM27964SQX-A/NOPB equivalent, this page provides verified package mapping (WQFN-24), confirmed current-setting resistor equations (ILED = 200 × 1.25V/RSET for Banks A/B; 800 × 1.25V/RSETK for keypad), validated thermal headroom (180mV at full scale), and real-world I²C register addressing (0x36, A0h/B0h).
Technical Context
The LM27964SQX-A/NOPB integrates an adaptive CMOS charge pump operating in 1× pass-through or 3/2× boost mode, automatically selected based on forward voltage monitoring of active Dxx pins (excluding DKEY). Its closed-loop regulation maintains POUT at ~4.6V in 3/2× mode while minimizing power loss by maximizing 1× operation across 2.7V–5.5V input range.
Three independent current-sink banks are digitally controlled via I²C: BankA (D1A–D4A) and BankB (D1B–D2B) support 16-step PWM dimming at fixed 10kHz (SQ-I) or 23kHz (SQ-C), while DKEY uses 4-level analog scaling (100%/70%/40%/20%). Each bank's full-scale current is set externally via RSET resistors tied to ISETA/ISETB/ISETK, with guaranteed 0.2% matching within banks.
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 ≤30mA per DxA/DxB pin (max 4×30mA + 2×30mA) and ≤80mA on DKEY. |
| Current Matching | 0.2% typical between sinks in same bank - ensures uniform luminance across multi-LED displays. |
| Charge Pump Efficiency | 87% peak - achieved via adaptive gain selection and low ROUT (2.75Ω typical) minimizing POUT droop. |
| I²C Address & Registers | 7-bit address 0x36; brightness control at A0h (BankA/B) and B0h (DKEY); general-purpose register at 10h. |
| Headroom Voltage | 180mV at full-scale current - defines minimum VPOUT–VLED required for regulation integrity. |
| Thermal Resistance | θJA = 41.3°C/W (RTW0024A package) - enables 100°C junction operation under 180mA load with proper PCB copper. |
Pinout & Package
LM27964SQX-A/NOPB is housed in a 4mm × 4mm × 0.8mm WQFN-24 package (TI package code RTW0024A) with exposed thermal pad (DAP) for enhanced heat dissipation. Pin numbering follows standard quad layout with pins 1–12 on top row and 13–24 on bottom row (viewed from top).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (24) | Main power input | Accepts 2.7V–5.5V Li-ion supply; feeds charge pump input and internal bias circuitry. |
| POUT (23) | Charge pump regulated output | Delivers boosted voltage (~4.6V in 3/2× mode) to all LED anodes; monitored for gain control. |
| D1A–D4A (13–16), D1B–D2B (4–5), DKEY (6) | Constant-current LED sink outputs | Each drives one LED cathode; current set by RSETA/RSETB/RSETK; forward voltage sensed for gain transition. |
| ISETA (17), ISETB (3), ISETK (12) | Current reference inputs | Resistor-to-GND sets full-scale current: ILED = 200×1.25V/RSET (A/B), 800×1.25V/RSETK (DKEY). |
| SCL (1), SDIO (2), VIO (7) | I²C interface signals | Support 100kHz–400kHz bus; VIO sets logic level (1.8V–VIN); SCL/SDIO tolerate VIN+0.3V max. |
| GND (9,10,18,DAP) | Ground reference | Multiple GND pins and exposed DAP minimize impedance; critical for stable current regulation and EMI control. |
| NC (8,11) | No-connect | Not internally bonded; must be left floating or tied to GND per layout best practice. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive 1×/3/2× charge pump | Automatically selects gain mode based on real-time LED forward voltage sensing - maximizes efficiency across battery voltage range. |
| 0.2% current matching within banks | Ensures consistent brightness across 4 main-display LEDs or 2 sub-display LEDs without manual calibration. |
| Independent triple-bank control | Enables simultaneous but separate brightness tuning of main LCD, sub LCD, and keypad - no shared registers or timing conflicts. |
| I²C-compatible 16-level PWM (BankA/B) | Provides flicker-free dimming at 10kHz (SQ-I) or 23kHz (SQ-C) - avoids audible noise and meets human-eye persistence requirements. |
| Dedicated keypad driver with analog scaling | 4 fixed brightness levels (100%/70%/40%/20%) reduce MCU processing overhead vs. PWM generation for low-current indicators. |
Applications
| Mobile Phone Main Display Backlight | Mobile Phone Sub Display Backlight |
|---|---|
Use Scenario: Dual-screen feature phone with primary 3.5" TFT and secondary 1.2" OLED display. IC Role / Device Role / Timing Role: LM27964SQX-A/NOPB acts as the sole LED driver, powering 4×30mA main-display LEDs and 2×30mA sub-display LEDs using shared POUT rail and independent I²C brightness registers. Use Value: Eliminates need for two discrete drivers; 0.2% current matching prevents visible luminance gradients across main display segments. |
Use Scenario: Flip phone with clamshell design where sub-display shows time/caller ID when closed. IC Role / Device Role / Timing Role: LM27964SQX-A/NOPB supplies regulated current to sub-display LEDs only when enabled via ENB bit in General Purpose Register (10h), reducing standby power. Use Value: Adaptive gain switching maintains sub-display brightness down to 2.7V battery voltage without efficiency penalty. |
| Mobile Keypad LED Illumination | PDA Backlight System |
Use Scenario: Feature phone keypad with 12 tactile keys requiring uniform indicator illumination. IC Role / Device Role / Timing Role: LM27964SQX-A/NOPB drives all 12 keys in parallel from DKEY pin using ballast resistors, controlled via B0h register for 4-level analog dimming. Use Value: 80mA DKEY capability supports multiple parallel LEDs; analog scaling avoids PWM-induced EMI in RF-sensitive keypad area. |
Use Scenario: Handheld PDA with QVGA main display and status LED bar requiring synchronized dimming. IC Role / Device Role / Timing Role: LM27964SQX-A/NOPB configures BankA for display backlight and DKEY for status LEDs, both controlled over same I²C bus with independent brightness commands. Use Value: Single-chip solution reduces BOM count and PCB area vs. discrete LED drivers; thermal resistance (41.3°C/W) sustains 180mA total load in compact enclosure. |
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 | Single-bank 16-channel driver (no sub-display or keypad grouping); requires external I²C expander for multi-bank control. | Lacks native dual-display partitioning and dedicated keypad current path - unsuitable for phones needing independent main/sub/keypad dimming. | Select LM27964SQX-A/NOPB when hardware-level bank separation and 80mA keypad drive are required. |
| TPS61165DRVR | Single-output boost converter LED driver; 30mA max per channel; no integrated I²C interface - requires external MCU GPIO/PWM. | Cannot natively support three independent brightness domains; lacks current-matching spec and adaptive gain logic. | Choose LM27964SQX-A/NOPB for integrated I²C control, guaranteed matching, and multi-rail efficiency optimization. |
Compared with LM3530UMX/NOPB and TPS61165DRVR, the LM27964SQX-A/NOPB uniquely combines triple-bank architecture, 0.2% matching, adaptive charge pump gain, and native I²C register mapping - enabling single-chip dual-display + keypad lighting without firmware complexity or external components.
Availability
LM27964SQX-A/NOPB is available at Aetrix Electronics and suitable for mobile phone backlighting, PDA display systems, and keypad illumination requiring stable component supply, long-term lifecycle support, and traceable sourcing for production programs.
Supply support for LM27964SQX-A/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 leader specializing in analog, embedded processing, and power management ICs, with decades of expertise in portable power and display solutions.
The LM27964SQX-A/NOPB belongs to TI's white LED driver product line, engineered specifically for space-constrained mobile devices needing high-efficiency, multi-bank backlight control with minimal external components.
FAQ
What is the I²C address of the LM27964SQX-A/NOPB and how are its brightness registers mapped?
The LM27964SQX-A/NOPB uses a fixed 7-bit I²C slave address of 0x36. Brightness is controlled via three internal registers: General Purpose Register at 0x10h (controls ENA/ENB/ENK enables), Bank A/B Brightness Control at 0xA0h (4-bit per bank, 16 levels), and Keypad Brightness Control at 0xB0h (2-bit, 4 analog levels). All registers are accessible using standard I²C write sequences with chip address, register address, and data byte.
How do I calculate the RSET resistor values for desired LED currents on the LM27964SQX-A/NOPB?
For BankA and BankB (D1A–D4A, D1B–D2B), use RSETA = 200 × 1.25V / ILED and RSETB = 200 × 1.25V / ILED; for example, 20mA per LED requires RSETA = 12.5kΩ. For DKEY, use RSETK = 800 × 1.25V / IKEY; e.g., 60mA total requires RSETK = 16.7kΩ. The LM27964SQX-A/NOPB holds ISET pin voltage at 1.25V (typ), making these calculations deterministic and stable across temperature.
Does the LM27964SQX-A/NOPB support PWM dimming on the keypad driver (DKEY)?
No - the LM27964SQX-A/NOPB applies analog current scaling to the DKEY output, offering only four fixed brightness levels: 100%, 70%, 40%, and 20%. This differs from BankA and BankB, which support 16-step PWM dimming at either 10kHz (LM27964SQ-I variant) or 23kHz (LM27964SQ-C variant). The LM27964SQX-A/NOPB datasheet confirms DKEY uses analog scaling exclusively, simplifying keypad control and reducing EMI.
What is the maximum allowable LED forward voltage for reliable operation of the LM27964SQX-A/NOPB at 2.7V input?
At VIN = 2.7V, the LM27964SQX-A/NOPB operates in 3/2× gain mode, delivering up to ~4.05V at POUT. Accounting for 180mV headroom requirement and typical 2.75Ω output resistance, the maximum sustainable VLED is approximately 3.6V for full-scale current. Exceeding this risks current regulation loss - verified in Electrical Characteristics Table (VDxTH = 375mV transition threshold) and Application Information section of the LM27964SQX-A/NOPB datasheet.
Can multiple Dxx outputs be paralleled on the LM27964SQX-A/NOPB to drive a single high-current LED?
Yes - D1A–D4A or D1B–D2B outputs may be wired in parallel to increase per-LED current. For example, connecting all four BankA outputs drives one LED at 4× the per-pin current (e.g., 120mA with 30mA/pin setting). RSETA must be recalculated so each sink contributes 25% of target current. The LM27964SQX-A/NOPB's electrical specs (ROUT, kHR, matching) remain valid in this configuration, as confirmed in the "Parallel Connected Outputs" subsection of the official datasheet.
LM27964SQX-A/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-A/NOPB FAQ
1.How can I place an order for LM27964SQX-A/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM27964SQX-A/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-A/NOPB reliable?
The price and inventory of LM27964SQX-A/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-A/NOPB is usually 5 days.
3.What payment methods are accepted for LM27964SQX-A/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM27964SQX-A/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM27964SQX-A/NOPB?
LM27964SQX-A/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM27964SQX-A/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-A/NOPB?
For technical support, including LM27964SQX-A/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM27964SQX-A/NOPB requirements.
6.How does Aetrix verify that LM27964SQX-A/NOPB is sourced from the original manufacturer or authorized distributors?
All LM27964SQX-A/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-A/NOPB meets industry standards.
7.What is the process for return or replacement of LM27964SQX-A/NOPB?
All LM27964SQX-A/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM27964SQX-A/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-A/NOPB part is unused and in its original packaging.
Return procedure for LM27964SQX-A/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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