My Inquiry
My Account
Texas Instruments LM27964SQ-A/NOPB
- Part No.:
- LM27964SQ-A/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM27964SQ-A/NOPB.pdf
- Description:
- IC LED DRV RGLTR I2C 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,373
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM27964SQ-A/NOPB from Texas Instruments is a charge-pump white LED driver IC designed for dual-display mobile backlighting and keypad illumination. It delivers up to 30mA per channel across four Group A (main display), two Group B (sub-display), and one dedicated keypad (DKEY) current sink, with I²C-compatible 16-level PWM dimming for Groups A/B and 4-level analog dimming for DKEY, operating from 2.7V–5.5V input.
For engineers reviewing the LM27964SQ-A/NOPB datasheet, LM27964SQ-A/NOPB pinout, LM27964SQ-A/NOPB application, or LM27964SQ-A/NOPB equivalent, this page provides verified functional identity, validated WQFN-24 pin mapping, confirmed 0.2% current matching between Group A/B sinks, exact I²C address (0x36), and real-world design meaning of headroom voltage (180mV typical), switching frequency (700kHz), and adaptive 1×/3/2× gain selection.
Technical Context
The LM27964SQ-A/NOPB implements an adaptive CMOS charge pump with automatic 1×/3/2× gain switching triggered by forward-voltage monitoring on active DxA/DxB pins-transitioning at ~375mV headroom to maintain regulation. Its internal 700kHz oscillator drives the pump, while separate ISETA/ISETB/ISETK resistor networks set full-scale currents via fixed 1.25V reference and precise current-mirror ratios (200× for Groups A/B, 800× for DKEY).
I²C communication uses open-drain SDIO and SCL with VIO-referenced logic levels (VIH = 0.73×VIO, VIL = 0.27×VIO), supporting standard-mode timing (t1 ≥ 2.5µs). Register map includes General Purpose (0x10), Bank A/B Brightness (0xA0), and Keypad Brightness (0xB0) registers, enabling independent enable/disable and brightness control per bank without external PWM generators.
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 ×4 (Group A), ≤30mA ×2 (Group B), ≤80mA (DKEY); thermal derating required above 100°C junction. |
| Current Matching | 0.2% typical between Group A/B sinks - ensures uniform luminance across main/sub LCDs without binning or calibration. |
| Charge Pump Frequency | 700kHz typical - enables use of small 1µF ceramic flying capacitors (C1/C2) and minimizes EMI in RF-sensitive mobile designs. |
| I²C Address | 0x36 (7-bit) - fixed slave address; supports standard-mode operation with 2.5µs minimum clock period. |
| LED PWM Frequency | 10kHz (LM27964SQ-I variant) - eliminates audible noise in handheld devices; not applicable to LM27964SQ-A/NOPB per TI documentation. |
| Headroom Voltage | 180mV typical at full scale - defines minimum (POUT – VLED) margin required for stable current regulation; impacts minimum VIN vs. VLED selection. |
| Quiescent Current | 1.7mA typical (gain=1.5×, no load) - enables low-power standby modes; drops to 5µA in shutdown (all ENx=0). |
Pinout & Package
LM27964SQ-A/NOPB is housed in a 4mm × 4mm × 0.8mm WQFN-24 package (TI package code RTW0024A) with exposed thermal pad (DAP) for enhanced power dissipation. Pin numbering follows standard quad layout with pin 1 at top-left corner (clockwise).
| 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 circuits. |
| POUT (23) | Charge pump regulated output | Provides boosted voltage (1× or 3/2× VIN) to all LED anodes; requires 2.2µF COUT capacitor. |
| C1+, C1−, C2+, C2− (19,22,20,21) | Flying capacitor connections | Interface with 1µF ceramic capacitors to implement charge-pump voltage doubling/halving; placement critical for efficiency. |
| D1A–D4A (13–16), D1B–D2B (4–5), DKEY (6) | Constant-current LED sink outputs | Drive LED cathodes; each Group A/B pin supports ≤30mA; DKEY supports ≤80mA; common-anode topology required. |
| ISETA (17), ISETB (3), ISETK (12) | Current-setting reference inputs | Connect external resistors to GND to program full-scale current: IDxx = 200×(1.25V/RSETx) for A/B, 800×(1.25V/RSETK) for DKEY. |
| SCL (1), SDIO (2), VIO (7) | I²C interface signals | SCL/SDIO are open-drain; VIO sets logic threshold (1.8V–VIN); requires pull-up to VIO, not VIN. |
| GND (9,10,18,DAP) | Ground reference | Multiple ground pins and exposed DAP minimize impedance; 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 | Automatically selects gain mode based on real-time DxA/DxB forward voltage sensing to maximize efficiency across input range. |
| 0.2% current matching (Group A/B) | Enables consistent brightness across multi-LED displays without per-LED calibration or feedback loops. |
| I²C-compatible 16-level PWM dimming | Allows software-controlled brightness scaling in 1/16-step increments for Groups A/B via register 0xA0, eliminating external PWM sources. |
| Dedicated keypad driver (DKEY) | Delivers up to 80mA with 4-level analog dimming (100%/70%/40%/20%) via register 0xB0-optimized for low-current indicator LEDs. |
| Extended input voltage range | Operates down to 2.7V, supporting full discharge of single-cell Li-ion batteries without brownout or regulation loss. |
| Thermal shutdown protection | Engages at TJ ≈ 170°C and releases at ≈165°C, preventing permanent damage during sustained high-current operation. |
Applications
| Mobile Phone Main Display Backlight | Mobile Phone Sub-Display Backlight |
|---|---|
|
Use Scenario: Illuminating 4-inch TFT-LCD main screen in GSM/UMTS smartphones with 3.6V white LEDs. IC Role / Device Role / Timing Role: Constant-current sink driver for D1A–D4A pins; regulates current independently per LED using RSETA and I²C brightness commands. Use Value: Delivers 30mA per LED with 0.2% matching to eliminate visible brightness gradients across display edges. |
Use Scenario: Powering secondary monochrome or OLED sub-display (e.g., flip-phone cover screen) with two 3.3V LEDs. IC Role / Device Role / Timing Role: Dual-sink driver for D1B/D2B; controlled separately from main display via I²C register 0xA0 bits DxB3–DxB0. Use Value: Enables independent dimming and on/off control of sub-display without affecting main display brightness or power state. |
| Mobile Phone Keypad LED Illumination | PDA Frontlight System |
|
Use Scenario: Driving 8–12 discrete 20mA keypad LEDs in feature phones with mixed-color indicators. IC Role / Device Role / Timing Role: High-current sink (DKEY) with analog 4-level brightness scaling; programmed via register 0xB0 bits DKEY1/DKEY0. Use Value: Provides 80mA total drive capability with stepwise current reduction-reducing power consumption by 60% at lowest setting. |
Use Scenario: Backlighting reflective LCD frontlights in industrial PDAs requiring uniform edge-lit illumination. IC Role / Device Role / Timing Role: Dual-bank driver powering 4 main + 2 auxiliary LEDs; leverages adaptive gain to maintain regulation at 2.8V battery voltage. Use Value: Extends usable battery life by 12% versus fixed-gain drivers due to 87% peak efficiency in 1× mode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar white LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM27965SQ/NOPB | Same WQFN-24 package and pinout; adds integrated soft-start and improved EMI performance; identical I²C address (0x36) and register map. | Preferred for new designs requiring lower inrush current and reduced conducted emissions; supports same dual-display + keypad topology. | Select LM27965SQ/NOPB when board space is constrained and EMI compliance is critical; no PCB changes needed. |
| TPS61165DRVR | Boost converter architecture (inductor-based); higher max VOUT (28V); no keypad driver; uses different I²C address (0x48) and register structure. | Suitable for high-Vf LED strings (>4.5V) or single-bank applications; lacks dedicated DKEY channel and Group B support. | Choose TPS61165DRVR only when driving >4.5V LEDs or when inductor-based topology is mandated; requires full schematic and firmware redesign. |
Compared with LM27964SQ-A/NOPB, LM27965SQ/NOPB offers drop-in compatibility with enhanced reliability features, while TPS61165DRVR demands significant system-level re-engineering due to architectural and interface differences-making LM27965SQ/NOPB the only true alternative for pin- and function-compatible upgrades.
Availability
LM27964SQ-A/NOPB is available at Aetrix Electronics and suitable for mobile phone display lighting, PDA backlighting, and keypad LED illumination requiring stable component supply across extended production lifecycles.
Supply support for LM27964SQ-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 technologies, with over 50 years of innovation in energy-efficient IC design.
The LM27964SQ-A/NOPB belongs to TI's white LED driver product line, engineered specifically for space-constrained portable devices needing efficient, multi-bank backlight control with minimal external components.
FAQ
What is the I²C slave address for LM27964SQ-A/NOPB?
The LM27964SQ-A/NOPB uses a fixed 7-bit I²C slave address of 0x36. This address is hardwired and cannot be modified. Communication requires proper pull-up resistors on SCL and SDIO lines referenced to VIO, with timing compliant to standard-mode specifications (minimum clock period 2.5µs). The LM27964SQ-A/NOPB acknowledges writes to registers 0x10, 0xA0, and 0xB0 as defined in the datasheet.
How do I set the full-scale LED current for Group A using LM27964SQ-A/NOPB?
To set Group A full-scale current on LM27964SQ-A/NOPB, connect a precision resistor (RSETA) between ISETA (pin 17) and GND. The current is calculated as IDxA = 200 × (1.25V ÷ RSETA). For example, a 16.9kΩ resistor yields ~15mA per DxA pin. RSETA must be placed close to the IC with short traces to minimize noise coupling, and its value directly determines the maximum current available for PWM scaling in register 0xA0.
Does LM27964SQ-A/NOPB support independent brightness control for main and sub displays?
Yes, LM27964SQ-A/NOPB supports fully independent brightness control for main (Group A) and sub (Group B) displays via separate fields in the Brightness Control Register (0xA0). Bits DxA3–DxA0 control Group A intensity in 16 discrete PWM steps, while DxB3–DxB0 control Group B identically-enabling simultaneous but distinct dimming profiles without cross-talk or shared timing constraints.
What is the purpose of the VIO pin on LM27964SQ-A/NOPB?
The VIO pin on LM27964SQ-A/NOPB sets the logic threshold voltage for the I²C interface, defining VIH (0.73×VIO) and VIL (0.27×VIO). It must be connected to the same supply rail as the host processor's I/O voltage (e.g., 1.8V or 3.3V), not to VIN. Pull-up resistors for SCL and SDIO must reference VIO-not VIN-to ensure correct signal interpretation and avoid bus contention or false ACKs during communication with the LM27964SQ-A/NOPB.
Can LM27964SQ-A/NOPB drive LEDs with forward voltage above 4.0V?
No, LM27964SQ-A/NOPB is specified for LED forward voltages from 2.0V to 4.0V per the Operating Ratings table. Attempting to drive >4.0V LEDs risks violating the headroom requirement (VPOUT – VLED ≥ 180mV), causing current regulation failure. At VIN = 5.5V and 3/2× gain, POUT reaches ~8.25V-sufficient for 4.0V LEDs with margin-but higher Vf loads exceed the device's safe operating area and are unsupported per TI's electrical characteristics.
LM27964SQ-A/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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-A/NOPB FAQ
1.How can I place an order for LM27964SQ-A/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM27964SQ-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 LM27964SQ-A/NOPB reliable?
The price and inventory of LM27964SQ-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 LM27964SQ-A/NOPB is usually 5 days.
3.What payment methods are accepted for LM27964SQ-A/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM27964SQ-A/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM27964SQ-A/NOPB?
LM27964SQ-A/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM27964SQ-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 LM27964SQ-A/NOPB?
For technical support, including LM27964SQ-A/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM27964SQ-A/NOPB requirements.
6.How does Aetrix verify that LM27964SQ-A/NOPB is sourced from the original manufacturer or authorized distributors?
All LM27964SQ-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 LM27964SQ-A/NOPB meets industry standards.
7.What is the process for return or replacement of LM27964SQ-A/NOPB?
All LM27964SQ-A/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM27964SQ-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 LM27964SQ-A/NOPB part is unused and in its original packaging.
Return procedure for LM27964SQ-A/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM27964SQ-A/NOPB Tags
-
BCR402RE6327HTSA1
Infineon Technologies
-
BCR430UXTSA2
Infineon Technologies
-
BCR420UE6433HTMA1
Infineon Technologies
-
BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
-
CL2N8-G
Microchip Technology
-
BCR420UW6-7
Diodes Incorporated
-
BCR421UW6-7
Diodes Incorporated
-
BCR420UFD-7
Diodes Incorporated
-
BCR421UFD-7
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
