AL3157F-7 LED Driver IC Equivalent & Substitute Parts

Part Overview

The AL3157F-7 is a 4-output LED driver IC manufactured by Diodes Incorporated, featuring a switched capacitor (charge pump) topology with PWM dimming capability. Designed for backlight applications, this device operates across a 2.7V to 5.5V supply range with 30mA and 210mA output channel capability. The part is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity.

Substiute Parts

AL3157F-7

Diodes IncorporatedIn Stock: 1843AL3157F-7 Datasheet

Current PartRFQ

AL3157F-7

Diodes IncorporatedIn Stock: 1843AL3157F-7 Datasheet

Parametric EquivalentRFQ

A8514KLPTR-T

Allegro MicroSystemsIn Stock: 25598A8514KLPTR-T Datasheet

MFR RecommendedRFQ

LM27952SD/NOPB

National SemiconductorIn Stock: 8348LM27952SD/NOPB Datasheet

MFR RecommendedRFQ

LTC3217EUD#PBF

Analog Devices Inc.In Stock: 4217LTC3217EUD#PBF Datasheet

MFR RecommendedRFQ

MAX1573ETE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1210MAX1573ETE+ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AL3157F-7 is determined by the following critical parameters:

• Topology Match: Switched Capacitor (Charge Pump) topology maintains functional equivalence
• Output Configuration: 4-output LED driver architecture
• Supply Voltage Compatibility: Operating range must encompass or overlap with 2.7V to 5.5V
• Current Capability: Output current per channel must meet or exceed 30mA minimum requirement
• Dimming Method: PWM dimming control
• Package Compatibility: Surface mount packages with exposed pad design
• Thermal Range: Operating temperature -40°C to 85°C minimum

Substitute parts are grouped into two categories: parametric equivalents (matching all critical parameters) and manufacturer-recommended alternatives (functionally compatible with topology or application differences).

Parameter Comparison

Engineering Selection Recommendations

MAX1573ETE+ (Parametric Equivalent) This part provides the closest functional match to the AL3157F-7. Both devices employ switched capacitor topology, support identical supply voltage range (2.7V to 5.5V), feature 4-output configuration with PWM dimming, and operate across the same temperature range. Current output per channel (28mA) is within 2mA of the AL3157F-7 specification. The device is active in production with ROHS3 compliance and unlimited moisture sensitivity rating. Package change from 12-UFDFN to 16-WQFN requires PCB layout modification.

LTC3217EUD#PBF (High Current Alternative) This Analog Devices part maintains switched capacitor topology and 4-output LED driver architecture with PWM dimming. Supply voltage range (2.9V to 4.5V) overlaps the AL3157F-7 operating window. Current capability per channel (150mA) significantly exceeds the original specification, providing design margin for higher brightness applications. Operating temperature range matches the original part. Active production status with ROHS3 compliance. Package transition from 12-UFDFN to 16-WFQFN requires layout redesign.

LM27952SD/NOPB (Functional Equivalent) National Semiconductor part maintains switched capacitor topology with 4-output configuration and PWM dimming. Supply voltage range (3V to 5.5V) encompasses the upper portion of AL3157F-7 operating range. Current output per channel (30mA) matches the minimum specification of the original device. Operating temperature and compliance specifications align with the original part. Active production status. Package change from 12-UFDFN to 14-WFDFN requires PCB modification.

A8514KLPTR-T (Topology Variant) This Allegro MicroSystems part represents a topology departure, employing step-up (boost) converter architecture instead of switched capacitor topology. Supply voltage range (5V to 40V) is incompatible with the lower end of AL3157F-7 specifications. Current capability per channel (80mA) exceeds original requirements. Extended operating temperature range (-40°C to 125°C) and automotive qualification (AEC-Q100) provide enhanced reliability for demanding applications. Suitable only for designs where boost topology and higher supply voltage are acceptable. Package change to 20-TSSOP-EP requires significant layout modification.

Frequently Asked Questions (FAQ)

Q: Can MAX1573ETE+ directly replace AL3157F-7 without circuit modification? A: MAX1573ETE+ provides functional equivalence in topology, output configuration, and electrical specifications. However, package change from 12-UFDFN to 16-WQFN requires PCB layout redesign. Pin-to-pin compatibility cannot be assumed; schematic review and layout validation are necessary.

Q: What is the primary reason for substituting AL3157F-7? A: The AL3157F-7 is classified as obsolete. Active production alternatives ensure long-term component availability and supply chain continuity for new designs and production support.

Q: Which substitute part maintains the smallest package footprint? A: LM27952SD/NOPB uses 14-WFDFN package, which is smaller than the 16-pin packages of MAX1573ETE+ and LTC3217EUD#PBF, but larger than the original 12-UFDFN. A8514KLPTR-T uses 20-TSSOP-EP, the largest package option.

Q: Is LTC3217EUD#PBF suitable for designs requiring exactly 30mA output current? A: LTC3217EUD#PBF provides 150mA per channel, significantly exceeding the 30mA requirement. This higher capability introduces design margin but may increase power dissipation and component cost compared to lower-current alternatives.

Q: Can A8514KLPTR-T be used in applications designed for AL3157F-7? A: A8514KLPTR-T employs step-up (boost) topology rather than switched capacitor topology and requires minimum 5V supply input. These differences make it unsuitable as a direct replacement unless circuit topology and power supply architecture are redesigned.

Q: What compliance certifications are common across all substitute parts? A: ROHS3 compliance is specified for AL3157F-7, MAX1573ETE+, LTC3217EUD#PBF, and A8514KLPTR-T. LM27952SD/NOPB compliance status is not specified in available documentation.

Q: Which substitute part offers the widest operating temperature range? A: A8514KLPTR-T operates from -40°C to 125°C, extending 40°C above the AL3157F-7 and other substitute parts. This extended range is supported by automotive qualification (AEC-Q100).