Texas Instruments LT1009CLP

Overview

LT1009CLP from Texas Instruments is a precision 2.5-V shunt voltage reference in TO-92 (LP) package, featuring ±5 mV initial tolerance (0.2% max), 15 ppm/°C typical temperature coefficient over 0°C to 70°C, and 0.6 Ω max dynamic impedance at 1 mA. It operates as a three-terminal adjustable reference with ANODE, CATHODE, and ADJ pins, enabling ±5% output trimming for system-level calibration in analog measurement circuits.

For engineers reviewing the LT1009CLP datasheet, LT1009CLP pinout, LT1009CLP application, or LT1009CLP equivalent, this device serves as a direct replacement for LM136-2.5 in low-power, cost-sensitive 2.5-V reference designs requiring stable output under varying load and temperature conditions without external trim components.

Technical Context

The LT1009CLP implements a bandgap-based shunt regulator architecture with on-chip laser trimming to achieve tight initial voltage accuracy and minimized αVZ. Its ADJ terminal allows fine-tuning of VZ by injecting current into the internal reference node, enabling ±5% adjustment while preserving low temperature drift.

It functions within a 400 µA–10 mA operating current range, delivers <15 mV full-range ΔVZ across 0°C–70°C, and maintains ≤1.4 Ω reference impedance up to 10 mA. The device draws no quiescent current when unpowered and exhibits 20 ppm/khr long-term stability at 25°C.

Key Specifications

Pinout & Package

LT1009CLP uses TO-92 (LP) package - 3-pin through-hole plastic case with straight or formed leads, 5.34 mm max height, and JEDEC TO-226 compliance. Pin 1 = ANODE, Pin 2 = CATHODE, Pin 3 = ADJ (adjust terminal). Pins 4–8 are NC (no internal connection).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt reference applications.

Compared with LM136-2.5, LT1009CLP offers tighter tolerance and built-in adjustability; compared with TL431ACLP, it achieves lower minimum operating current and eliminates external resistor dependency for basic 2.5-V use cases.

Availability

LT1009CLP is available at Aetrix Electronics and suitable for industrial data acquisition, portable instrumentation, and current-loop transmitter designs requiring stable component supply with consistent parametric performance across production lots.

Supply support for LT1009CLP 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 company specializing in analog and embedded processing technologies, with decades of leadership in precision reference design.

The LT1009 product line was developed to deliver high-accuracy, low-drift shunt references for cost-sensitive industrial and test equipment where LM136 limitations in tolerance and adjustability constrained system performance.

FAQ

What is the maximum operating current for LT1009CLP?

The LT1009CLP supports a maximum operating current of 10 mA per the Absolute Maximum Ratings table. At this current, its dynamic impedance remains ≤1.4 Ω, and thermal dissipation stays within safe limits for the TO-92 package at ambient temperatures up to 70°C. Exceeding 10 mA risks exceeding the 150°C junction temperature limit.

Can LT1009CLP replace LM136-2.5 without PCB changes?

Yes, LT1009CLP is specified as directly interchangeable with LM136-2.5 in the datasheet and shares identical TO-92 pinout (ANODE–CATHODE–ADJ vs LM136's ANODE–CATHODE–NC). No PCB modifications are needed, though the ADJ pin may be left open or grounded depending on whether adjustment is used in the target design.

What is the purpose of the ADJ pin on LT1009CLP?

The ADJ pin on LT1009CLP allows ±5% adjustment of the 2.5-V reference voltage by injecting current into the internal reference node. This enables system-level calibration to compensate for PCB trace resistance, op-amp input offset, or sensor nonlinearity-without requiring external trim pots or resistor networks.

Does LT1009CLP require external capacitors for stability?

No, LT1009CLP does not require external capacitors for stability in standard shunt configurations. Its internal design ensures unconditional stability with purely resistive loads. However, a 0.1 µF ceramic bypass capacitor is recommended at the CATHODE pin to suppress high-frequency noise in noisy power environments.

What is the long-term stability specification for LT1009CLP?

LT1009CLP exhibits a long-term drift of 20 ppm per kilohour at 25°C, equivalent to approximately 0.175% change over 10 years of continuous operation. This value is measured under controlled conditions with 1 mA bias current and reflects typical aging behavior for the device's bandgap structure and packaging.