UA7908CKCS Equivalent & Substitute Parts

Part Overview

The UA7908CKCS is a linear voltage regulator IC manufactured by Texas Instruments, designed to provide a fixed negative 8V output at 1.5A in a TO-220-3 through-hole package. This device is classified as Last Time Buy, indicating limited future availability. Finding equivalent and substitute parts is necessary to ensure design continuity and long-term supply chain reliability for applications requiring negative voltage regulation in this performance class.

Substiute Parts

UA7908CKCS

Texas InstrumentsIn Stock: 1426UA7908CKCS Datasheet

Current PartRFQ

TPS7A3301RGWR

Texas InstrumentsIn Stock: 1514TPS7A3301RGWR Datasheet

MFR RecommendedRFQ

L7908CV

STMicroelectronicsIn Stock: 88990L7908CV Datasheet

DirectRFQ

UA7908CKCSE3

Texas InstrumentsIn Stock: 1390UA7908CKCSE3 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the UA7908CKCS are grouped based on the following critical parameters that determine functional compatibility:

• Output Configuration & Voltage: Negative polarity with fixed -8V output
• Output Current Capability: Minimum 1.5A continuous output
• Package Type: TO-220-3 through-hole mounting for direct PCB compatibility
• Input Voltage Range: Support for -25V maximum input
• Protection Features: Over current, over temperature, and short circuit protection
• Compliance: ROHS3 compliance and EAR99 classification

Substitutes are classified into two categories:

Parametric Equivalent: UA7908CKCSE3 — Identical electrical specifications and package, direct pin-compatible replacement.

Direct Manufacturer Equivalent: L7908CV (STMicroelectronics) — Functionally equivalent with identical output specifications, same TO-220-3 package, and compatible protection features, though product status is Obsolete.

Advanced Substitute (Adjustable Alternative): TPS7A3301RGWR — Higher performance adjustable regulator with superior specifications but different package (20-VQFN surface mount), requiring circuit redesign.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (No Circuit Modification Required):

UA7908CKCSE3 is the primary substitute. It provides identical electrical performance, package compatibility, and protection features. Both devices share Last Time Buy status, so long-term availability planning remains necessary for both options.

L7908CV (STMicroelectronics) is a functional equivalent with identical output specifications and TO-220-3 package. However, its Obsolete product status makes it unsuitable for new designs or long-term production. Existing inventory may be available but future sourcing is not guaranteed.

For Enhanced Performance (Circuit Redesign Required):

TPS7A3301RGWR offers superior specifications including adjustable output voltage, lower dropout voltage (0.8V vs 1.1V), higher PSRR (72dB vs 60dB), and Active product status. This device requires surface-mount assembly and circuit redesign to accommodate the adjustable output topology. It is suitable for new designs prioritizing performance and long-term availability.

All substitute options maintain ROHS3 compliance and EAR99 classification, ensuring regulatory consistency.

Frequently Asked Questions (FAQ)

Q: Can UA7908CKCSE3 be used as a direct drop-in replacement for UA7908CKCS?

A: Yes. UA7908CKCSE3 is pin-compatible with identical electrical specifications, output voltage (-8V), output current (1.5A), package (TO-220-3), and protection features. No circuit modification is required.

Q: Why is L7908CV listed as a substitute if it is Obsolete?

A: L7908CV provides functional equivalence with identical output specifications and package. It is included for reference in applications where existing inventory is available. For new designs or long-term production, UA7908CKCSE3 or TPS7A3301RGWR are preferred.

Q: What are the key differences between the fixed-output substitutes and TPS7A3301RGWR?

A: TPS7A3301RGWR is an adjustable regulator (-1.18V to -33V output range) versus fixed -8V output. It uses a 20-VQFN surface-mount package instead of TO-220-3 through-hole, requiring PCB redesign and assembly process changes. Output current is 1A versus 1.5A. Dropout voltage is lower (0.8V vs 1.1V), and PSRR is higher (72dB vs 60dB).

Q: Can TPS7A3301RGWR be configured to output -8V?

A: Yes, the adjustable output range of TPS7A3301RGWR (-1.18V to -33V) includes -8V. However, this requires external resistor network configuration and circuit redesign. The fixed-output alternatives (UA7908CKCSE3 or L7908CV) are simpler for applications requiring fixed -8V output.

Q: Are all substitutes ROHS3 compliant?

A: Yes. UA7908CKCSE3, L7908CV, and TPS7A3301RGWR are all ROHS3 compliant, maintaining regulatory consistency with the original UA7908CKCS.

Q: What is the impact of Last Time Buy status on UA7908CKCS and UA7908CKCSE3?

A: Last Time Buy status indicates limited future manufacturing. Current inventory is available (1350 Pcs for UA7908CKCS, 1370 Pcs for UA7908CKCSE3), but production will not continue. For applications requiring long-term supply, TPS7A3301RGWR with Active status is recommended for new designs.

Q: Can the TO-220-3 package be replaced with the 20-VQFN package in existing designs?

A: No. The 20-VQFN package requires surface-mount assembly and different PCB layout. Through-hole TO-220-3 designs cannot directly accommodate surface-mount components without significant PCB redesign and assembly process changes.