Texas Instruments LT1054IDW

Overview

LT1054IDW from Texas Instruments is a bipolar switched-capacitor voltage converter with integrated regulation, functioning as a negative voltage generator or regulated charge pump. It delivers up to 100 mA output current with typical voltage loss of 1.1 V at 100 mA, operates from 3.5 V to 15 V input, and provides a 2.5 V internal reference for precision feedback. It is used in RS-232 interface supplies requiring stable –5 V rails.

For engineers reviewing the LT1054IDW datasheet, LT1054IDW pinout, LT1054IDW application, or LT1054IDW equivalent, key selection considerations include its regulated negative output capability, shutdown control via FB/SD pin, oscillator synchronization support, and SOIC-16 package compatibility with industrial temperature range (–40°C to 85°C).

Technical Context

The LT1054IDW implements an adaptive-switch drive architecture that dynamically adjusts switching behavior to maintain high efficiency across 10 mA–100 mA load currents. Its internal 25 kHz oscillator can be externally synchronized or tuned using capacitors on the OSC pin, enabling system-level clock alignment and ripple optimization.

Regulation is achieved through an integrated error amplifier with FB/SD serving as both inverting input and shutdown control node. The device uses a bipolar process to achieve low switch resistance and supports external resistor dividers to set precise negative output voltages - e.g., –5 V with R1 = 20 kΩ and R2 = 102.5 kΩ - while maintaining <50 mV output regulation over load variation.

Key Specifications

Pinout & Package

LT1054IDW is housed in a 16-pin SOIC (DW) package measuring 10.30 mm × 10.30 mm, with exposed pad not present and standard JEDEC MS-013AC footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar switched-capacitor voltage converter applications.

Compared with LT1054CDW, the LT1054IDW offers guaranteed operation down to –40°C and wider reference tolerance for robustness in variable-temperature systems; compared with MAX680CPD+, it provides design flexibility via programmable regulation and active shutdown - critical for energy-conscious embedded systems.

Availability

LT1054IDW is available at Aetrix Electronics and suitable for industrial communications (RS-232), data acquisition bias rails, and programmable negative regulator designs requiring stable component supply across extended temperature ranges.

Supply support for LT1054IDW 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 leadership in power management and precision analog ICs.

The LT1054 product line was designed to replace discrete charge-pump solutions with integrated, regulated switched-capacitor converters for industrial and communications systems requiring compact, reliable negative voltage generation.

FAQ

What is the maximum output current capability of the LT1054IDW?

The LT1054IDW delivers up to 100 mA of regulated output current under recommended operating conditions (VCC = 3.5 V to 15 V, TA = –40°C to 85°C). At 100 mA, typical voltage loss is 1.1 V, meaning a 6.1 V minimum input is required for a –5 V output. Peak switch current capability is 300 mA, but sustained output is thermally limited to 100 mA in the SOIC-16 package.

How does the LT1054IDW achieve output voltage regulation?

The LT1054IDW achieves regulation using an internal 2.5 V reference and error amplifier. The FB/SD pin serves as the inverting input: connecting an external resistor divider (e.g., R1 = 20 kΩ, R2 = 102.5 kΩ) between VOUT and GND sets the regulated output (e.g., –5 V). The error amplifier drives internal PNP switches to maintain VOUT stability against input and load variations - delivering <50 mV output regulation over 10–100 mA loads.

Can the LT1054IDW be synchronized to an external clock?

Yes, the LT1054IDW supports external oscillator synchronization via the OSC pin (Pin 13). An open-collector gate or NPN transistor can drive this pin at the desired system clock frequency, allowing multiple LT1054IDW devices to operate in phase alignment. A 20 kΩ pull-up to VREF is recommended. This feature reduces beat-frequency noise in multi-converter systems and simplifies EMI filtering.

What capacitors are required for stable operation of the LT1054IDW?

The LT1054IDW requires three key external capacitors: a 2 µF ceramic or film capacitor between CAP+ and CAP− (flying capacitor), a 10 µF low-ESR tantalum capacitor from VCC to GND (input bypass), and a 100 µF low-ESR tantalum capacitor from VOUT to GND (output filter). Additionally, a 0.002 µF capacitor from FB/SD to GND improves load regulation. All capacitors must be low-ESR to minimize voltage loss and ripple.

Does the LT1054IDW support parallel operation for higher current?

Yes, the LT1054IDW supports parallel operation to increase total output current and reduce output ripple. When paralleling multiple LT1054IDW units, synchronize their OSC pins to a common clock and introduce small phase offsets (e.g., 90° between two units) to distribute switching events. Ensure matched external components and low-impedance shared VOUT/GND paths. Output current scales nearly linearly - two units deliver ~190 mA with improved thermal margin.