LT3094IMSE -20V 500mA Ultralow Noise Ultrahigh PSRR Negative LDO | ADI
N.º da peça: LT3094IMSE ✓ AtivoLT3094IMSE Visão geral
A low-dropout (LDO) linear regulator maintains a regulated output voltage using a pass element that operates in its linear region; the LT3094 is a NEGATIVE-output LDO, meaning its output sits below ground (e.g. -5V, -12V) rather than above ground like a conventional LDO. Within the broader taxonomy it belongs to linear regulators, then voltage regulators, then power management ICs, then semiconductors. Negative LDOs are commonly used to bias RF power amplifiers, op-amp negative rails, and high-speed ADC front-ends where a quiet negative supply is mandatory.
Key features include a bipolar architecture achieving 0.8 uVrms noise, 90 dB PSRR at 1 kHz, programmable current limit, fast start-up capability, programmable power-good output, and a tracking function that controls an upstream supply to minimize the LT3094's power dissipation and optimize PSRR. A bipolar enable pin and exposed thermal pad complete the integration story for compact, high-performance designs.
The architecture uses an internal reference, error amplifier, and pass transistor optimized for ultralow-noise and ultrahigh-PSRR operation; the tracking function uniquely minimizes VIN-to-VOUT drop, reducing on-chip dissipation while preserving PSRR across frequency. This combination enables the part to follow a noisy upstream supply while presenting a clean rail to the load.
Typical applications include RF power amplifier biasing, high-speed data converter negative supplies, op-amp negative rails, low-noise instrumentation, and precision test equipment where both ultralow noise and high PSRR are mandatory for system SNR. Industrial temperature grades (-40C to +125C) make the part suitable for factory and outdoor deployments.
Designers should size the SET-pin resistor to program output voltage, ensure sufficient input/output capacitance for stability per datasheet curves, and leverage the tracking input to minimize the input-to-output differential in high-current rails. Thermal design must account for the exposed pad soldered to a sufficient copper pour.
This page synthesizes distributor pricing, drop-in alternatives and ADI/MSOP-EP application notes not consolidated on a single manufacturer page, giving engineers a faster path from spec to PCB.
Alternativas drop-in para LT3094IMSE — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
LT3094EMSE#PBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LT3094IMSE#TRPBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LT3094EMSE#TRPBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LT3094IMSE Classificações máximas e características elétricas
| Manufacturer | Analog Devices |
| MPN | LT3094IMSE |
| Topologia | Negative-Output LDO Linear Regulator |
| Faixa de tensão de entrada | -20 V to 0 V |
| Faixa de tensão de saída | 0 V to -19.5 V (programmable via SET pin) |
| Output Current | 500 mA |
| Ruído de saída | 0.8 uVrms (10 Hz to 100 kHz) |
| PSRR | 90 dB at 1 kHz |
| Pino de habilitação | Yes (bipolar, active logic) |
| Programmable Current Limit | Yes |
| Power Good | Yes (programmable) |
| Tracking Function | Yes (drives upstream supply to minimize drop and optimize PSRR) |
| Temperatura de operação | -40C to +125C (Industrial, 'I' grade) |
| Encapsulamento | 12-MSOP-EP (MSE), exposed thermal pad |
| Tipo de montagem | Surface Mount |
| RoHS / Lead-Free | Yes (#PBF suffix) |
| Datasheet Revision | Rev B |
Configuração de pinos do LT3094IMSE
| Pino 1 | OUT — Regulated negative output voltage |
| Pino 2 | SENSE — Kelvin sense connection to load |
| Pino 3 | IN — Negative input supply voltage (-20V max) |
| Pino 4 | GND — Ground reference for SET pin |
| Pino 5 | SET — Output voltage programming pin (50uA reference current) |
| Pino 6 | TRACK — Tracking input - drives upstream supply to minimize drop and optimize PSRR |
| Pino 7 | EN — Bipolar enable pin (active) |
| Pino 8 | PWRGD — Power-good indicator output |
| Pino 9 | ILIM — Programmable current-limit setting |
| Pino 10 | BYP — Noise bypass capacitor pin |
| Pino 11 | NC — Not connected (per datasheet) |
| Pino 12 | NC — Not connected (per datasheet) |
Aplicações típicas
LT3094IMSE é adequado para 6 aplicaçãos: RF Power Amplifier Bias Supply, High-Speed ADC Negative Supply, Low-Noise Op-Amp Negative Rail, Test and Measurement Instrumentation, Industrial Process Control and Factory Automation, Medical Imaging and Diagnostic Front-End.
RF Power Amplifier Bias Supply
The LT3094IMSE is well suited as the negative bias rail for RF power amplifiers in macro base stations, small-cell radios and GaN/Si-LNA front-ends. Its 0.8 uVrms integrated noise (10 Hz to 100 kHz) and 90 dB PSRR at 1 kHz ensure that regulator noise does not degrade amplifier gain or EVM. The 500 mA output supports multi-PA bias chains, while the tracking function dynamically minimizes dropout to optimize PSRR and reduce dissipation across load steps and temperature.
Recomendado
High-Speed ADC Negative Supply
Precision SAR and pipeline ADCs often require a low-noise negative supply (typically -5V or -12V) for input common-mode biasing or front-end analog stages. The LT3094IMSE delivers up to 500 mA from a -20V (max) input with 0.8 uVrms noise and 90 dB PSRR at 1 kHz, ensuring that converter SNR and SFDR are not degraded by regulator noise. Industrial temperature grade and exposed-pad MSOP-EP support dense, multi-ADC signal-acquisition boards.
Recomendado
Low-Noise Op-Amp Negative Rail
High-precision op-amps (e.g. zero-drift, precision instrumentation) need a quiet negative supply to avoid coupling ripple into the signal path. The LT3094IMSE provides 500 mA at 0.8 uVrms noise and 90 dB PSRR at 1 kHz - sufficient for the most demanding precision front-ends. The bipolar enable pin and programmable power-good output simplify multi-rail sequencing in instrumentation and process-control hardware operating from -40C to +125C.
Recomendado
Test and Measurement Instrumentation
Bench-top and ATE instruments require clean negative rails for analog signal conditioning, DAC reference circuits, and sensor excitation. The LT3094IMSE's 0.8 uVrms noise floor and tracking function enable low-distortion signal chains, while the 500 mA rating supports multi-channel conditioning blocks. The exposed-pad MSOP-EP package allows compact PCB layouts behind connector panels where board area is limited.
Recomendado
Industrial Process Control and Factory Automation
Industrial 4-20 mA loops, isolated sensor front-ends, and PLC analog modules demand reliable negative supplies with high PSRR to reject noisy 24V industrial bus transients. The LT3094IMSE operates from -40C to +125C (industrial grade) and delivers 500 mA with 90 dB PSRR, making it well suited for factory-floor equipment. The bipolar enable and tracking function support modular system power-up sequencing.
Recomendado
Medical Imaging and Diagnostic Front-End
Ultrasound beamformers, patient monitoring analog front-ends and electrochemical analyzers all require ultra-clean negative rails for low-level signal acquisition. The LT3094IMSE's 0.8 uVrms noise and 90 dB PSRR at 1 kHz preserve the integrity of microvolt-level biosignals. The 12-MSOP-EP footprint supports the dense PCB layouts of portable diagnostic carts and handheld analyzers with 500 mA of usable output current.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para LT3094IMSE — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | LT3094EMSE#PBF | LT3094IMSE#TRPBF | LT3094EMSE#TRPBF |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 12-MSOP-EP (MSE) | 12-MSOP-EP (MSE) - same | 12-MSOP-EP (MSE) - same | 12-MSOP-EP (MSE) - same |
| Output Current | 500 mA | 500 mA | 500 mA | 500 mA |
| Output Noise (10 Hz to 100 kHz) | 0.8 uVrms | 0.8 uVrms | 0.8 uVrms | 0.8 uVrms |
| PSRR at 1 kHz | 90 dB | 90 dB | 90 dB | 90 dB |
| Temperature Grade | Industrial (-40C to +125C) | Extended (E grade) | Industrial | Extended (E grade) |
| Output Polarity | Negative | Negative | Negative | Negative |
| RoHS / Lead-Free | Yes (#PBF) | Yes (#PBF) | Yes (#PBF) | Yes (#PBF) |
Principais diferenciais
- Highest-PSRR negative LDO with integrated tracking function (vs LT3094EMSE#PBF)
- 0.8 uVrms integrated noise floor (vs Standard negative LDOs (typical 20-50 uVrms))
- Pin-compatible scaling across temperature grades (vs LT3090MPMSE (non-pin-compatible))
Notas de projeto
Estimated: at VIN=-15V, VOUT=-5V, and IOUT=500 mA, the LT3094IMSE dissipates approximately (15V-5V) x 0.5A = 5 W. With the 12-MSOP-EP thermal pad soldered to at least 1 square inch of 1 oz copper, theta_JA drops to roughly 30 C/W and junction temperature rise stays below 150C above ambient. The exposed pad MUST be soldered for thermal performance - omitting it can cause thermal shutdown well below rated current.
Place input and output capacitors as close to the IN and OUT pins as possible. Use low-ESR ceramic capacitors meeting the datasheet minimums for stability; the BYP capacitor (typically 10 nF) sets the noise bandwidth and must be a low-leakage ceramic. A small RC filter at SET can further reduce output noise at low frequencies; verify stability on the bench with a network analyzer when deviating from datasheet-recommended values.
Do not exceed -20V at the IN pin or apply reverse polarity - the LT3094 is a negative-rail LDO and will be damaged by positive input. The tracking pin must remain within its allowed common-mode range or PSRR will degrade. Program ILIM with a resistor to set current limit slightly above the maximum expected load to avoid nuisance trips. Always respect the datasheet's current-limit foldback curve - at VIN-VOUT > 7V the current limit derates.
Route the SENSE pin directly to the load for Kelvin sensing, eliminating IR-drop errors across PCB traces. Keep the SET-pin trace short and guarded from switching signals to avoid coupling that would appear as additional output noise. The exposed thermal pad should be stitched with thermal vias to an internal ground plane for optimal heat spreading to datasheets.
Informações de conformidade
Lead-free (#PBF) finish per ADI ordering nomenclature. RoHS compliant per manufacturer product page. AEC-Q100 not applicable for industrial-grade linear regulator; choose automotive-grade ADI parts for vehicular applications. Halogen-free status not stated in provided data - marked unknown.
