LM2794TL LED Driver IC Equivalent & Substitute Parts

Part Overview

The LM2794TL is a 4-output LED driver IC manufactured by Texas Instruments, featuring a switched capacitor (charge pump) topology with integrated PWM and analog dimming capabilities. Designed for backlight applications, this component operates across a 2.7V to 5.5V supply range with 20mA per-channel output current and 515kHz switching frequency.

The LM2794TL is classified as obsolete. Identifying equivalent and substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and support long-term product availability for applications currently using this component.

Substiute Parts

LM2794TL

Texas InstrumentsIn Stock: 1601LM2794TL Datasheet

Current PartRFQ

LM2794TL/NOPB

Texas InstrumentsIn Stock: 3104LM2794TL/NOPB Datasheet

DirectRFQ

AL3157F-7

Diodes IncorporatedIn Stock: 1843AL3157F-7 Datasheet

MFR RecommendedRFQ

MAX8822ETE+

Analog Devices Inc./Maxim IntegratedIn Stock: 822MAX8822ETE+ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM2794TL is determined by the following critical parameters:

Primary Compatibility Criteria:

• Topology: Switched Capacitor (Charge Pump)
• Number of Outputs: 4
• Supply Voltage Range: 2.7V to 5.5V (minimum overlap required)
• Dimming Control: PWM capability (required for backlight applications)
• Internal Switching: Yes (integrated switch requirement)
• Applications: Backlight

Secondary Considerations:

• Current per Channel: 20mA baseline; higher ratings acceptable for design margin
• Switching Frequency: 515kHz reference; alternative frequencies acceptable within thermal and EMI constraints
• Package Type: Surface mount variants acceptable with PCB layout adaptation
• Product Status: Active status preferred for long-term availability; obsolete alternatives acceptable if other parameters align

Substitute parts are grouped into two categories: direct equivalents (identical electrical specifications with packaging variations) and functional alternatives (compatible topology and electrical range with parameter variations).

Parameter Comparison

Engineering Selection Recommendations

LM2794TL/NOPB (Direct Equivalent - Recommended Primary Substitute)

The LM2794TL/NOPB is the direct functional equivalent of the LM2794TL, manufactured by Texas Instruments with identical electrical specifications. This part maintains the same 14-DSBGA package, 4-output configuration, 2.7V to 5.5V supply range, 20mA per-channel current, and dual dimming control (Analog/PWM). The primary advantage is active product status, ensuring ongoing availability. The LM2794TL/NOPB carries ROHS3 compliance and MSL-1 rating, providing superior environmental and moisture handling compared to the obsolete original. Packaging is Tape & Reel (TR), suitable for automated assembly. This substitute requires no design modification.

AL3157F-7 (Functional Alternative - Topology Compatible)

The AL3157F-7 from Diodes Incorporated maintains the switched capacitor topology and 4-output configuration required for backlight applications. Supply voltage range (2.7V to 5.5V) and operating temperature range (-40°C to 85°C) are compatible. Current per channel is rated at 30mA and 210mA, providing higher output capability than the LM2794TL's 20mA. Switching frequency is 1.2MHz, higher than the original 515kHz. Dimming control is PWM only (analog dimming not available). Package is 12-UFDFN, requiring PCB layout redesign. Product status is obsolete. ROHS3 compliance and MSL-1 rating are provided. This substitute is suitable when higher output current is required and analog dimming is not essential.

MAX8822ETE+ (Functional Alternative - Topology Compatible)

The MAX8822ETE+ from Analog Devices Inc./Maxim Integrated provides switched capacitor topology with 4-output configuration and full supply voltage compatibility (2.7V to 5.5V). Current per channel is 24mA, exceeding the LM2794TL's 20mA specification. Switching frequency is 1MHz. Dimming control is PWM only. Output voltage is specified at 5V, differing from the LM2794TL's 3.8V. Package is 16-TQFN (3x3), requiring PCB layout redesign. Product status is active, ensuring long-term availability. ROHS3 compliance and MSL-1 rating are provided. This substitute is suitable for designs where 5V output and higher current capacity are acceptable and analog dimming is not required.

Frequently Asked Questions (FAQ)

Q: Can LM2794TL/NOPB be used as a direct replacement for LM2794TL?

A: Yes. The LM2794TL/NOPB is electrically and functionally identical to the LM2794TL. Both share the same 14-DSBGA package, 4-output configuration, 2.7V to 5.5V supply range, 20mA per-channel current, 515kHz switching frequency, and dual dimming control (Analog/PWM). No design modification is required. The primary difference is product status (active vs. obsolete) and improved compliance ratings (ROHS3, MSL-1).

Q: What are the key differences between LM2794TL and AL3157F-7?

A: Both use switched capacitor topology and support 4-output backlight applications with 2.7V to 5.5V supply compatibility. Key differences include: AL3157F-7 provides higher current per channel (30mA, 210mA vs. 20mA), operates at higher switching frequency (1.2MHz vs. 515kHz), supports PWM dimming only (no analog control), uses a different package (12-UFDFN vs. 14-DSBGA), and has a wider operating temperature range (-40°C to 85°C vs. -30°C to 85°C). PCB layout redesign is required.

Q: What are the key differences between LM2794TL and MAX8822ETE+?

A: Both use switched capacitor topology and support 4-output backlight applications with 2.7V to 5.5V supply compatibility. Key differences include: MAX8822ETE+ provides higher current per channel (24mA vs. 20mA), operates at higher switching frequency (1MHz vs. 515kHz), supports PWM dimming only (no analog control), specifies 5V output voltage (vs. 3.8V), uses a different package (16-TQFN vs. 14-DSBGA), and has a wider operating temperature range (-40°C to 85°C vs. -30°C to 85°C). PCB layout redesign is required.

Q: Is analog dimming control available in substitute parts?

A: Analog dimming control is available only in the LM2794TL/NOPB, which maintains the original dual dimming capability (Analog/PWM). Both AL3157F-7 and MAX8822ETE+ support PWM dimming only. If analog dimming is required for your application, LM2794TL/NOPB is the only suitable substitute among these options.

Q: What packaging considerations apply when selecting a substitute?

A: The LM2794TL/NOPB uses the same 14-DSBGA package as the original, requiring no PCB layout modification. AL3157F-7 uses 12-UFDFN packaging, and MAX8822ETE+ uses 16-TQFN (3x3) packaging. Both alternatives require PCB redesign, including footprint changes, trace routing adjustments, and thermal management evaluation. Verify PCB space availability and thermal requirements before selecting an alternative package.

Q: Which substitute offers the best long-term availability?

A: LM2794TL/NOPB and MAX8822ETE+ both carry active product status, ensuring ongoing manufacturer support and supply chain availability. AL3157F-7 is classified as obsolete. For long-term design continuity, LM2794TL/NOPB is the preferred choice due to identical specifications and active status.

Q: Are all substitutes RoHS and REACH compliant?

A: The original LM2794TL is RoHS non-compliant. All three substitutes (LM2794TL/NOPB, AL3157F-7, MAX8822ETE+) are ROHS3 compliant and REACH unaffected. If RoHS compliance is a design requirement, any of the three substitutes meets this criterion.