A6277EA-T LED Driver IC Equivalent & Substitute Parts

Part Overview

The A6277EA-T is a linear LED driver IC manufactured by Allegro MicroSystems, designed for 8-output shift register applications with 120mA per-channel output capability. This component is classified as obsolete, making equivalent and substitute parts necessary for new designs and production continuity. The part operates within a 4.5V to 5.5V supply range and is packaged in a 20-DIP through-hole configuration. Substitute parts must maintain functional compatibility through equivalent shift register topology, internal switching capability, and 8-output architecture while accommodating variations in electrical specifications and packaging formats.

Substiute Parts

A6277EA-T

Allegro MicroSystemsIn Stock: 1135A6277EA-T Datasheet

Current PartRFQ

MAX6970AUE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 736MAX6970AUE+T Datasheet

MFR RecommendedRFQ

MAX6978AUE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 756MAX6978AUE+T Datasheet

MFR RecommendedRFQ

TB62785NG

Toshiba Semiconductor and StorageIn Stock: 826TB62785NG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the A6277EA-T is determined by the following critical parameters: linear topology with shift register configuration, 8-output architecture, internal switching capability, and ROHS3 compliance. All substitute parts maintain these core functional requirements. However, substitutes vary in three key areas:

1. Supply Voltage Range: The A6277EA-T operates at 4.5V–5.5V. Substitute parts may support extended ranges (3V–5.5V), allowing operation in broader application contexts.

2. Output Current per Channel: The A6277EA-T delivers 120mA per channel. Substitute parts provide reduced current ratings (50mA–55mA), requiring circuit redesign for applications demanding the original 120mA specification.

3. Package and Mounting: The A6277EA-T uses 20-DIP through-hole packaging. Substitute parts employ surface-mount packages (16-TSSOP or 24-SDIP), necessitating PCB layout modifications and assembly process changes.

4. Output Voltage Rating: Substitute parts specify maximum output voltages (5.5V–36V), whereas the A6277EA-T specifies 4V. This parameter affects load-driving capability in specific applications.

Parameter Comparison

Engineering Selection Recommendations

For Through-Hole Mounting Requirement: The TB62785NG is the only substitute maintaining through-hole packaging (24-SDIP). It preserves the mounting compatibility of the A6277EA-T while offering active product status and ROHS3 compliance. However, output current is reduced to 50mA per channel, and output voltage is specified at 17V compared to the original 4V.

For Surface-Mount Applications: Both MAX6970AUE+T and MAX6978AUE+T provide active product status with extended operating temperature range (-40°C to 125°C versus -40°C to 85°C). The MAX6970AUE+T supports higher output voltage (36V), while MAX6978AUE+T is rated for 5.5V output. Both reduce output current to 55mA per channel and require PCB redesign for surface-mount assembly.

For Supply Voltage Flexibility: MAX6970AUE+T and MAX6978AUE+T support 3V minimum supply voltage, enabling operation in lower-voltage systems compared to the A6277EA-T's 4.5V minimum.

All substitute parts maintain ROHS3 compliance and shift register topology with 8 outputs and internal switching, satisfying core functional requirements for LED driver applications.

Frequently Asked Questions (FAQ)

Q: Can MAX6970AUE+T or MAX6978AUE+T directly replace A6277EA-T in existing PCB designs?

A: No. Both parts use 16-TSSOP surface-mount packaging versus the A6277EA-T's 20-DIP through-hole package. PCB layout and assembly process modifications are required. Pin configuration and signal routing differ between packages.

Q: What is the primary limitation when substituting with TB62785NG?

A: Output current per channel is reduced from 120mA to 50mA. Applications requiring the full 120mA specification must be redesigned or use alternative components. The 24-SDIP through-hole package maintains mounting compatibility.

Q: Are the MAX6970AUE+T and MAX6978AUE+T interchangeable?

A: Both parts share identical package, topology, output current (55mA), and supply voltage specifications. The primary difference is output voltage rating: MAX6970AUE+T is rated for 36V output, while MAX6978AUE+T is rated for 5.5V output. Selection depends on load voltage requirements.

Q: Do substitute parts support the same operating temperature range as A6277EA-T?

A: TB62785NG matches the A6277EA-T at -40°C to 85°C. MAX6970AUE+T and MAX6978AUE+T extend the range to -40°C to 125°C, providing broader thermal operating capability.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. A6277EA-T, MAX6970AUE+T, MAX6978AUE+T, and TB62785NG are all ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating.

Q: What supply voltage range is supported by each substitute?

A: TB62785NG and A6277EA-T both require 4.5V–5.5V supply. MAX6970AUE+T and MAX6978AUE+T support extended range of 3V–5.5V, allowing operation in lower-voltage applications.