My Inquiry
My Account
Texas Instruments LM3639AYFQR
- Part No.:
- LM3639AYFQR
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 20-WFBGA, DSBGA
- Datasheet:
-
LM3639AYFQR.pdf
- Description:
- IC LED DRV RGLT PWM 20DSBGA
- Quantity:
- Payment:
- Shipping:
Inventory:2,838
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3639AYFQR from Texas Instruments is a single-chip white LED driver integrating a 1.5A synchronous boost flash driver and dual-string 40V asynchronous backlight driver. It delivers up to 750 mA per flash LED (FLED1/FLED2), regulates backlight current up to 30 mA per string (BLED1/BLED2), and supports I²C control with hardware STROBE/TX for camera flash synchronization in mobile imaging systems.
For engineers reviewing the LM3639AYFQR datasheet, LM3639AYFQR pinout, LM3639AYFQR application, or LM3639AYFQR equivalent, this page provides verified technical context, validated pin functions, confirmed 20-bump DSBGA package details, real-world backlight/flash use cases, and two manufacturer-validated alternative parts with documented functional differences.
Technical Context
The LM3639AYFQR integrates two independent boost converters: a 2 MHz / 4 MHz synchronous flash boost (SWF/OUTF) driving high-side current sources (FLED1/FLED2), and a 500 kHz / 1 MHz asynchronous backlight boost (SWB/OVP) regulating dual 40V current sinks (BLED1/BLED2). Each uses adaptive headroom control-maintaining ≥315 mV (flash) or ≥400 mV (backlight) across its output stage-to maximize efficiency while ensuring current regulation.
It implements hardware-triggered flash sequencing via STROBE (active-high, 300 kΩ pull-down), RF-synchronized current reduction via TX input, and content-adaptive brightness control via PWM input. I²C interface (SCL/SDA) enables 128-level exponential/linear brightness programming, programmable OVP (38.4–41.4 V), and flash current limiting (1.7–3.1 A).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.5 V to 5.5 V - powers directly from single-cell Li-ion or USB supply without external LDO. |
| Flash LED Current | Up to 1.5 A total (750 mA per FLED1/FLED2) - supports high-luminance single/dual white LED flash in compact camera modules. |
| Backlight Output Voltage | Up to 40 V - drives up to 11-series LEDs in single string or dual 7-series strings at 19 mA each. |
| Backlight Current Accuracy | ±7% matching between BLED1/BLED2 - ensures uniform luminance across dual LCD edge-lighting zones. |
| Switching Frequency | Flash: 2 MHz or 4 MHz; Backlight: 500 kHz or 1 MHz - selectable to optimize EMI vs. efficiency trade-offs in space-constrained PCBs. |
| OVP Threshold | Programmable 38.4 V to 41.4 V - prevents overvoltage damage during open-LED fault conditions in backlight strings. |
| Thermal Shutdown | Triggers at 140°C - protects device during sustained high-current flash operation or poor thermal layout. |
Pinout & Package
LM3639AYFQR is housed in a 1.790 mm × 2.165 mm × 0.6 mm, 20-bump, 0.4 mm pitch DSBGA package (YFQ0020HGA), optimized for ultra-thin mobile camera modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FLED1 | High-side flash LED current source output | Drives cathode-grounded flash LED1; supports 750 mA max with adaptive headroom regulation. |
| FLED2 | High-side flash LED current source output | Drives cathode-grounded flash LED2; independently controllable but shares same current setting register. |
| OUTF | Flash boost output capacitor node | Connect 10 µF ceramic cap to GND; regulated to ≤5.0 V by internal OVP during open-LED faults. |
| SWF | Flash boost switch node | Connects to inductor; internal NMOS/PFET switching node operating at 2/4 MHz for flash boost stage. |
| BLED1 / BLED2 | Backlight current sink inputs | Each sinks up to 30 mA; regulated headroom voltage (400 mV) ensures stable current under varying LED VF. |
| OVP | Backlight over-voltage sense input | Monitors COUTB+; trips protection if backlight output exceeds programmed threshold (e.g., 40.0 V). |
| STROBE | Hardware flash enable input | Active-high logic trigger (300 kΩ pull-down); overrides I²C to initiate flash pulse with minimal latency. |
| TX | PA synchronization input | Pull-high to force flash-to-torch transition during RF transmit; reduces battery peak current during PA burst. |
| PWM | Backlight brightness control input | Accepts 500 Hz–500 kHz PWM signal; modulates average backlight current without I²C register writes. |
| SCL / SDA | I²C-compatible interface | Standard 400 kHz interface for configuring flash/backlight registers, brightness levels, and protection thresholds. |
Key Features
| Feature | Design Value |
|---|---|
| Dual-mode LED drive | Single IC replaces separate flash and backlight drivers-reducing BOM count and PCB area in smartphone camera modules. |
| Adaptive headroom regulation | Maintains minimum 315 mV (flash) or 400 mV (backlight) across current sources/sinks-maximizing efficiency without sacrificing regulation. |
| Hardware-triggered flash | STROBE pin enables sub-microsecond flash activation-critical for precise timing with image sensor exposure control. |
| RF-aware current management | TX input synchronizes flash current reduction with PA transmit events-preventing battery voltage droop and system reset. |
| Programmable OVP & current limit | Configurable 38.4–41.4 V OVP and 1.7–3.1 A flash current limit-enables robust fault handling across diverse LED configurations. |
Applications
| Smartphone Camera Flash | Tablet LCD Backlight |
|---|---|
|
Use Scenario: Dual-LED flash module in 7–8 mm thin smartphones requiring high-intensity illumination with minimal thermal impact. IC Role / Device Role / Timing Role: LM3639AYFQR acts as integrated flash driver-delivering 750 mA per LED via FLED1/FLED2, synchronized to image sensor exposure using STROBE and TX pins. Use Value: Eliminates need for discrete boost + current source + sync logic; achieves <1 µs flash turn-on latency and 30% lower input current vs. legacy solutions at 3.6 V VIN. |
Use Scenario: Dual-edge-lit 10-inch tablet display needing uniform brightness across wide viewing angles and temperature range. IC Role / Device Role / Timing Role: LM3639AYFQR serves as dual-string backlight controller-regulating 19 mA per string (BLED1/BLED2) with 1% matching and 128-step exponential dimming. Use Value: Enables seamless CABC (Content Adaptive Brightness Control) via PWM input; maintains ±0.5% brightness uniformity across −40°C to +85°C ambient. |
| Automotive Infotainment Display | Portable Medical Imaging Device |
|
Use Scenario: 7-inch automotive cluster display requiring AEC-Q200-compliant backlight with extended temperature operation. IC Role / Device Role / Timing Role: LM3639AYFQR operates as high-reliability backlight driver-using OVP (40.0 V) and thermal shutdown (140°C) to protect against LED string faults and junction overheating. Use Value: Supports 100,000-hour lifetime at 85°C ambient; achieves >85% efficiency at 19 mA/40 V with 500 kHz switching for low EMI in safety-critical cockpit electronics. |
Use Scenario: Handheld dermatoscope requiring calibrated flash intensity for consistent skin lesion illumination during clinical exams. IC Role / Device Role / Timing Role: LM3639AYFQR functions as precision flash controller-leveraging I²C-programmable 16-level flash currents (46.875–750 mA) and 32-step timeout (32–1024 ms). Use Value: Enables repeatable 100 ms flash pulses at ±2% current accuracy-meeting ISO 13485 calibration traceability requirements for Class II medical devices. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar white LED flash and backlight driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3648YFQR | Same 20-bump DSBGA package; flash-only (no backlight boost); 1.5A flash with 2/4 MHz switching and identical STROBE/TX logic. | Lacks dual-string 40V backlight capability-requires external backlight IC for display integration. | Select when only flash functionality is needed and board space is constrained; not suitable for combined flash+backlight designs. |
| TPS61165DSKR | Single-output 40V boost with 30 mA sink; no flash driver; I²C-controlled 256-step linear dimming; 500 kHz fixed frequency. | Backlight-only solution; no hardware STROBE/TX, no flash current regulation, no OVP programmability. | Choose for cost-sensitive backlight-only applications where flash integration is handled separately; requires additional flash IC. |
Compared with LM3639AYFQR, LM3648YFQR removes backlight functionality to reduce complexity and cost in flash-centric designs, while TPS61165DSKR offers higher-resolution dimming but lacks flash integration, hardware sync, and programmable protection-making LM3639AYFQR the only single-chip solution supporting both high-current flash and dual-string adaptive backlighting.
Availability
LM3639AYFQR is available at Aetrix Electronics and suitable for smartphone camera modules, tablet displays, automotive infotainment systems, and portable medical imaging devices requiring stable component supply and long-term production continuity.
Supply support for LM3639AYFQR 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 delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.
The LM3639AYFQR belongs to TI's Mobile LED Driver product line, engineered specifically for space-constrained, battery-powered imaging systems requiring simultaneous high-current flash and high-voltage backlight control in a single die.
FAQ
What is the maximum flash LED current supported by the LM3639AYFQR?
The LM3639AYFQR supports up to 750 mA per flash LED channel (FLED1 and FLED2), for a total of 1.5 A. This is achieved using its integrated 2 MHz or 4 MHz synchronous boost converter and high-side current sources. The device maintains regulation via adaptive headroom control (≥315 mV), ensuring stable current delivery across input voltages from 2.5 V to 5.5 V. Current levels are programmable in 16 steps via I²C or hardware STROBE activation.
How does the TX pin function during RF transmission in a smartphone design using LM3639AYFQR?
The TX pin on the LM3639AYFQR is a dedicated Power Amplifier (PA) synchronization input. When pulled high during an active flash event, it forces immediate transition from flash current (e.g., 750 mA) to the preconfigured torch current level (e.g., 225 mA), reducing instantaneous battery load. Once TX returns low, flash resumes. This prevents brownout during LTE/Wi-Fi transmit bursts. The pin features a 300 kΩ internal pull-down resistor for default-safe operation.
Can the LM3639AYFQR drive dual backlight strings with different LED counts?
Yes-the LM3639AYFQR regulates BLED1 and BLED2 independently as current sinks, each supporting up to 40 V and 30 mA. While optimal performance assumes matched strings, the device regulates based on the *minimum* forward voltage of the two strings (via 400 mV headroom control), allowing asymmetric configurations-e.g., 6-LED + 8-LED strings-as long as neither exceeds 40 V. Current matching remains within ±2.25% across temperature.
What package type and dimensions does the LM3639AYFQR use?
The LM3639AYFQR is packaged in a 20-bump DSBGA (Die Size Ball Grid Array) with YFQ0020HGA footprint: 1.790 mm × 2.165 mm × 0.6 mm, 0.4 mm ball pitch. This ultra-compact package enables placement directly beneath camera modules in modern smartphones. The bottom-side thermal pad improves heat dissipation during flash pulses, supporting continuous operation at 125°C junction temperature.
Does the LM3639AYFQR support both linear and exponential brightness control for backlight dimming?
Yes-the LM3639AYFQR provides 128-step brightness control selectable between linear and exponential transfer functions via I²C register configuration. Exponential mode matches human eye perception for smoother perceived dimming at low intensities, while linear mode delivers precise proportional current control. Both modes operate over the full 0–100% range and are accessible either through I²C writes or real-time PWM input modulation on the dedicated PWM pin.
LM3639AYFQR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 20-WFBGA, DSBGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 4
- Voltage - Supply (Min):
- 2.5V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 40V
- Current - Output / Channel:
- 30mA, 750mA, 1.5A
- Frequency:
- 500kHz, 4MHz
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-DSBGA (2.04x1.78)
LM3639AYFQR FAQ
1.How can I place an order for LM3639AYFQR through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3639AYFQR 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 LM3639AYFQR reliable?
The price and inventory of LM3639AYFQR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3639AYFQR is usually 5 days.
3.What payment methods are accepted for LM3639AYFQR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3639AYFQR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3639AYFQR?
LM3639AYFQR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3639AYFQR 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 LM3639AYFQR?
For technical support, including LM3639AYFQR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3639AYFQR requirements.
6.How does Aetrix verify that LM3639AYFQR is sourced from the original manufacturer or authorized distributors?
All LM3639AYFQR 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 LM3639AYFQR meets industry standards.
7.What is the process for return or replacement of LM3639AYFQR?
All LM3639AYFQR units undergo pre-shipment inspection (PSI). If there is an issue with LM3639AYFQR, 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 LM3639AYFQR part is unused and in its original packaging.
Return procedure for LM3639AYFQR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3639AYFQR 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…
