Texas Instruments UA748CP

Overview

UA748CP from Texas Instruments is a general-purpose operational amplifier with external frequency compensation, wide common-mode input range (±12 V), input offset voltage null capability, and short-circuit protected output. It delivers 0.5 V/µs slew rate, 20–200 V/mV large-signal gain, and operates from ±15 V supplies in industrial temperature range (0°C to 70°C) - used in precision analog signal conditioning, active filters, and instrumentation front-ends.

For engineers reviewing the UA748CP datasheet, UA748CP pinout, UA748CP application, or UA748CP equivalent, key selection considerations include its uncompensated architecture requiring external 30-pF capacitor for unity-gain stability, offset-null terminal configuration, and compatibility with legacy uA709-based designs where bandwidth or slew rate optimization is needed.

Technical Context

The UA748CP implements a classic bipolar-input op-amp topology with high-input impedance (0.3–2 MΩ), differential pair input stage, and Class-A output stage with short-circuit protection. Its open-loop gain rolls off at –20 dB/decade only after external compensation sets dominant pole location.

Unlike internally compensated op-amps (e.g., UA741), the UA748CP's frequency response and transient behavior are fully configurable via external components connected between COMP, N1, and N2 pins - enabling tailored trade-offs between bandwidth, phase margin, and slew rate across closed-loop gains >1.

Key Specifications

Pinout & Package

UA748CP is housed in an 8-pin plastic dual-in-line package (PDIP-P), compliant with JEDEC MS-001, with 0.300-inch body width and 0.100-inch lead pitch. The package features through-hole mounting and standard DIP footprint compatibility.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar operational amplifier applications.

Compared with LM741CP and TL081CP, the UA748CP uniquely supports external compensation and offset nulling in a legacy-compatible 8-pin DIP footprint - making it suitable for upgrading existing uA709/uA741 designs where gain-bandwidth or DC accuracy must be improved without full schematic revision.

Availability

UA748CP is available at Aetrix Electronics and suitable for industrial instrumentation, analog filter design, and legacy system repair requiring stable component supply and long-term obsolescence mitigation.

Supply support for UA748CP 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 founded in 1930, specializing in analog, embedded processing, and logic technologies with broad industrial and automotive portfolio coverage.

The UA748CP belongs to TI's legacy general-purpose op-amp family designed for flexibility in analog signal conditioning - emphasizing configurability, ruggedness, and backward compatibility with early discrete and IC-based instrumentation systems.

FAQ

What is the primary functional distinction between UA748CP and UA741CP?

The UA748CP lacks internal frequency compensation and instead provides dedicated COMP, N1, and N2 pins for external capacitor and offset-null configuration - allowing engineers to optimize bandwidth, slew rate, and stability per closed-loop gain. In contrast, UA748CP requires a 30-pF capacitor for unity-gain stability, whereas UA741CP is internally compensated and ready for immediate use. This makes UA748CP more adaptable but also demands careful compensation design.

Does UA748CP support rail-to-rail input or output operation?

No, UA748CP does not support rail-to-rail operation. Its common-mode input range is specified as ±12 V with ±15 V supplies, and output swing is ±10 V into 2-kΩ loads. Input signals must remain within ±12 V of ground, and outputs cannot reach within ~2 V of either supply rail. This limitation is inherent to its bipolar transistor architecture and distinguishes UA748CP from modern rail-to-rail op-amps.

Can UA748CP be used as a comparator?

Yes, UA748CP can operate open-loop as a comparator due to its high open-loop gain (>20 V/mV) and lack of internal clamping or phase-reversal issues. However, it lacks dedicated comparator features like fast propagation delay or built-in hysteresis - so external positive feedback is required for noise immunity. For high-speed or precision threshold detection, purpose-built comparators (e.g., LM311) are preferred, but UA748CP remains viable in low-frequency, cost-sensitive applications.

What is the recommended compensation capacitor value for UA748CP in a unity-gain inverter configuration?

For unity-gain stable operation, TI specifies a 30-pF capacitor connected between the COMP pin (Pin 5) and VCC– (Pin 4). This value ensures adequate phase margin (>45°) and prevents oscillation when driving moderate capacitive loads. If closed-loop gain exceeds 1, the capacitor may be reduced (e.g., to 10–15 pF) to increase bandwidth - but stability must be verified experimentally or via SPICE simulation for each specific layout and load condition.

Is UA748CP RoHS-compliant and lead-free?

No - according to TI's packaging documentation, UA748CP (PDIP-P package) was manufactured prior to RoHS enforcement and is classified as non-RoHS, containing lead in solder and terminations. TI lists its status as OBSOLETE with no Pb-Free (RoHS) conversion plan defined. For new designs requiring compliance, alternatives such as TL081CP (RoHS-compliant SOIC variant) or modern rail-to-rail op-amps should be evaluated, though they require layout and schematic adaptation.