My Inquiry
My Account
STMicroelectronics LF90CDT-TR
__2.jpg)
- Part No.:
- LF90CDT-TR
- Manufacturer:
- STMicroelectronics
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
LF90CDT-TR.pdf
- Description:
- IC REG LINEAR 9V 500MA DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:3,563
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LF90CDT-TR from STMicroelectronics is a 9 V fixed-output, very low dropout (LDO) linear regulator in DPAK package with logic-controlled shutdown, 500 mA output current capability, ±2% output voltage accuracy at 25°C, and operation over –40 to 125°C junction temperature. It serves as a local power supply for microcontroller cores, sensor interfaces, and battery-powered industrial modules requiring stable low-noise voltage under tight input headroom.
For engineers reviewing the LF90CDT-TR datasheet, LF90CDT-TR pinout, LF90CDT-TR application, or LF90CDT-TR equivalent, key selection criteria include dropout voltage at 500 mA load, quiescent current in ON/OFF modes, shutdown logic compatibility (TTL), thermal resistance (RthJA = 100°C/W), and minimum 2.2 µF ceramic output capacitance for stability.
Technical Context
The LF90CDT-TR implements a PNP pass transistor architecture enabling ultra-low dropout voltage (0.45 V typical at 200 mA, ≤0.7 V at 500 mA), internal current and thermal limiting, and TTL-compatible enable control on Pin 2. Its design targets systems where input-to-output differential is constrained-e.g., single-cell Li-ion or multi-cell alkaline supplies powering 9 V rail-sensitive analog circuitry.
It operates without external compensation, requiring only a 2.2 µF ±20% ceramic output capacitor with ESR between 0.1 Ω and 10 Ω. Supply voltage rejection remains ≥76 dB up to 1 kHz, and output noise is specified at 50 µVRMS (10 Hz–100 kHz), supporting noise-sensitive ADCs and RF front-ends.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 9.0 V ±2% at 25°C; maintains regulation across –40 to 125°C junction range |
| Max Output Current | 500 mA continuous; internally current-limited to 1 A peak |
| Dropout Voltage | 0.45 V typ. at 200 mA; ≤0.7 V max at 500 mA - enables operation from 9.7 V input |
| Quiescent Current | 500 µA typ. in ON mode; 50 µA typ. in OFF (shutdown) mode - extends battery life |
| Input Voltage Range | 2.5 V to 16 V DC - supports wide-input battery and adapter-fed systems |
| Supply Rejection | 76 dB min. at 120 Hz; 71 dB at 1 kHz - suppresses ripple from switching pre-regulators |
| Thermal Resistance | RthJA = 100°C/W (DPAK); RthJC = 8°C/W - requires minimal PCB copper for thermal management |
| Operating Temp | –40°C to +125°C junction - qualified for automotive under-hood and industrial control environments |
Pinout & Package
DPAK (TO-252) thermally enhanced surface-mount package with exposed thermal pad (pin 2 is tab/thermal pad, electrically connected to Pin 2 - GND).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (IN) | Input voltage supply | Accepts 2.5–16 V DC; connects to bulk input capacitor (≥1 µF) |
| 2 (GND) | Ground reference & thermal pad | Primary return path; soldered thermal pad lowers junction-to-ambient resistance |
| 3 (EN) | Enable/shutdown control | TTL-compatible input: <0.8 V = OFF (50 µA IQ), >2.0 V = ON (500 µA IQ) |
| 4 (OUT) | Regulated output | Delivers stable 9.0 V ±2%; requires ≥2.2 µF ceramic capacitor with 0.1–10 Ω ESR |
| 5 (NC) | No connect | Internally unconnected; left floating or tied to GND per layout best practice |
Key Features
| Feature | Design Value |
|---|---|
| Very low dropout | 0.45 V typical at 200 mA - allows use with marginal input margins (e.g., 9.5 V → 9 V) |
| Logic-controlled shutdown | Pin 3 accepts TTL-level signals; reduces IQ to 50 µA - enables system-level power gating |
| Low-noise regulation | 50 µVRMS output noise (10 Hz–100 kHz) - suitable for precision analog and RF bias rails |
| Minimal external components | Stable with only 2.2 µF ceramic CO - eliminates tantalum, saves board space and cost |
| Robust protection | Integrated current limit and thermal shutdown - prevents damage during overload or poor heatsinking |
| Wide temperature range | Specified from –40°C to +125°C - meets AEC-Q100 Grade 1 requirements for automotive applications |
Applications
| Industrial PLC I/O Module | Automotive Body Control Unit |
|---|---|
Use Scenario: Powers isolated analog sensor signal conditioning circuitry in DIN-rail mounted controllers. IC Role / Device Role / Timing Role: Local 9 V LDO supplying op-amps and ADC references; enabled only during active measurement cycles. Use Value: 50 µA shutdown current minimizes standby power; 0.45 V dropout permits operation from aging 12 V bus (down to 9.5 V). |
Use Scenario: Supplies 9 V rail to LIN transceiver and window motor driver logic in door module. IC Role / Device Role / Timing Role: Primary 9 V regulator with EN controlled by MCU GPIO to disable subsystems during sleep mode. Use Value: RthJA = 100°C/W and –40°C to 125°C rating ensure reliability in sealed, high-temp cabin environments. |
| Portable Medical Monitor | Smart Energy Meter |
Use Scenario: Provides clean 9 V supply to ECG front-end amplifiers and display backlight drivers. IC Role / Device Role / Timing Role: Low-noise LDO decoupling switching DC/DC converter output; EN synchronized with acquisition bursts. Use Value: 50 µV RMS noise avoids interference with µV-level biopotential signals; ±2% accuracy ensures consistent gain calibration. |
Use Scenario: Regulates 9 V for metrology ADC, RTC, and PLC communication interface in utility-grade meter. IC Role / Device Role / Timing Role: Always-on LDO with thermal protection during extended surge events on AC mains input stage. Use Value: Internal thermal shutdown prevents latch-up during 150°C ambient exposure; 16 V max input withstands transient surges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LDL112PU33R | 3.3 V output, 200 mA, 170 mV dropout, DFN package | Lower current, lower voltage, no shutdown pin - unsuitable for 9 V/500 mA use | Select only if system requires 3.3 V and footprint constraints favor DFN |
| ST715M90R | 9 V output, 150 mA, 600 mV dropout, SOT-23 package | Lower current, higher dropout, same EN logic - insufficient for 500 mA loads | Use only in space-constrained, low-power subcircuits where 150 mA suffices |
Compared with LF90CDT-TR, LDL112PU33R and ST715M90R offer smaller footprints but sacrifice output current and dropout performance; LF90CDT-TR remains optimal for 500 mA, 9 V, thermally demanding applications requiring shutdown control and DPAK thermal robustness.
Availability
LF90CDT-TR is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, portable medical monitors, and smart energy meters requiring stable component supply with long-term lifecycle assurance.
Supply support for LF90CDT-TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, power, microcontroller, and sensor solutions for automotive, industrial, and consumer markets.
The LF00 series was developed specifically for low-dropout, low-quiescent-current regulation in battery-powered and thermally constrained systems - emphasizing simplicity, reliability, and wide operating temperature coverage.
FAQ
What is the minimum input voltage required for regulation at full 500 mA load?
The LF90CDT-TR maintains regulation down to an input voltage of 9.7 V at 500 mA load, based on its maximum dropout voltage of 0.7 V. Below this, output voltage drops linearly with input; operation below 2.5 V input is prohibited per absolute maximum ratings.
Can the NC pin (Pin 5) be connected to ground for improved thermal performance?
Pin 5 is internally unconnected and must remain floating per STMicroelectronics design. Connecting it to ground provides no thermal benefit and risks unintended electrical coupling; thermal performance relies solely on proper soldering of the exposed tab (Pin 2/GND) to a large copper pour.
Is the 2.2 µF output capacitor mandatory, or can larger values be used?
A 2.2 µF ceramic capacitor is the minimum required for stability with ESR between 0.1 Ω and 10 Ω. Larger values (e.g., 4.7–10 µF) are acceptable and improve transient response, but avoid electrolytics or high-ESR capacitors which may cause oscillation or startup issues.
Does the LF90CDT-TR support reverse polarity protection on the input?
No. The LF90CDT-TR lacks integrated reverse-voltage protection. Applying negative voltage to Pin 1 (IN) relative to Pin 2 (GND) exceeds absolute maximum rating (–0.5 V) and may cause permanent damage. External protection diode or MOSFET-based reverse-polarity circuitry is required in such systems.
LF90CDT-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 16V
- Voltage - Output (Min/Fixed):
- 9V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.7V @ 500mA
- Current - Output:
- 500mA
- Current - Quiescent (Iq):
- 1.5 mA
- Current - Supply (Max):
- 12 mA
- PSRR:
- 71dB ~ 56dB (120Hz ~ 10kHz)
- Control Features:
- -
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
LF90CDT-TR FAQ
1.How can I place an order for LF90CDT-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for LF90CDT-TR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LF90CDT-TR reliable?
The price and inventory of LF90CDT-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LF90CDT-TR is usually 5 days.
3.What payment methods are accepted for LF90CDT-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LF90CDT-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LF90CDT-TR?
LF90CDT-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LF90CDT-TR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LF90CDT-TR?
For technical support, including LF90CDT-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LF90CDT-TR requirements.
6.How does Aetrix verify that LF90CDT-TR is sourced from the original manufacturer or authorized distributors?
All LF90CDT-TR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LF90CDT-TR meets industry standards.
7.What is the process for return or replacement of LF90CDT-TR?
All LF90CDT-TR units undergo pre-shipment inspection (PSI). If there is an issue with LF90CDT-TR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LF90CDT-TR part is unused and in its original packaging.
Return procedure for LF90CDT-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LF90CDT-TR Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
