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STMicroelectronics LDK120C18R
- Part No.:
- LDK120C18R
- Manufacturer:
- STMicroelectronics
- Package:
- 5-TSSOP, SC-70-5, SOT-353
- Datasheet:
-
LDK120C18R.pdf
- Description:
- IC REG LIN 1.8V 200MA SOT323-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,300
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Product details
Overview
LDK120C18R from STMicroelectronics is a 200 mA, 1.8 V fixed-output low-dropout (LDO) regulator with 100 mV typical dropout at 100 mA, 100 µA max quiescent current, ±2.0% output voltage tolerance at 25 °C, and operation from 1.9 V to 5.5 V input. It delivers ultra-low noise (51 µVRMS, 10 Hz–100 kHz with 10 nF bypass) and logic-controlled shutdown (<1 µA OFF-mode current), targeting power rails in portable battery-powered systems.
For engineers reviewing the LDK120C18R datasheet, LDK120C18R pinout, LDK120C18R application, or LDK120C18R equivalent, key selection criteria include dropout performance under 200 mA load, ceramic-capacitor stability (1 µF COUT), thermal shutdown threshold (160 °C), enable logic thresholds (0.4 V low / 1.2 V high), and SOT323-5L package footprint compatibility.
Technical Context
The LDK120C18R employs a PMOS pass transistor architecture enabling ultra-low dropout and near-zero gate-drive current, eliminating external compensation requirements. Its internal bandgap reference and error amplifier maintain tight DC accuracy across –40 °C to 125 °C junction temperature.
It integrates logic-controlled enable with hysteresis-free TTL/CMOS-compatible thresholds, short-circuit constant-current limiting (400 mA typ.), and thermal foldback protection activating at 160 °C with 20 °C hysteresis - all without external components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8 V ±2.0% at 25 °C; ensures stable core voltage for 1.8 V I/O or low-power microcontrollers. |
| Max Output Current | 200 mA guaranteed; supports moderate-current peripherals like sensors, RF front-ends, or display drivers. |
| Dropout Voltage | 100 mV typ. at 100 mA; enables regulation from 1.9 V input down to 1.8 V output, maximizing battery runtime. |
| Quiescent Current | 60 µA typ. at no load; minimizes standby power loss in always-on subsystems. |
| Output Noise | 51 µVRMS (10 Hz–100 kHz, 10 nF bypass); meets stringent analog/RF supply noise requirements. |
| PSRR | 55 dB (120 Hz–10 kHz); suppresses ripple from noisy switching supplies feeding the LDO input. |
| Operating Temp | –40 °C to 125 °C junction; qualified for industrial and extended-temperature embedded applications. |
Pinout & Package
LDK120C18R is packaged in SOT323-5L - a 1.8 mm × 2.0 mm, 0.95 mm height surface-mount package with 0.65 mm lead pitch, optimized for space-constrained portable designs.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | IN | Main input voltage supply rail (1.9–5.5 V); requires local 1 µF ceramic decoupling capacitor. |
| 2 | GND | Power ground reference for regulator feedback and internal circuitry; must be low-impedance connection. |
| 3 | EN | Active-high enable control: <0.4 V = shutdown (<1 µA), >1.2 V = active; compatible with 1.8 V logic. |
| 4 | BYP/NC | Bypass pin for noise reduction on fixed versions; left floating if unused - no board routing required. |
| 5 | OUT | Regulated 1.8 V output; stable with 1 µF ceramic capacitor; supports up to 200 mA load current. |
Key Features
| Feature | Design Value |
|---|---|
| Ceramic capacitor stability | Stable with ≥1 µF X5R/X7R ceramic output capacitor - eliminates need for tantalum or electrolytic types. |
| Ultra-low noise architecture | 51 µVRMS output noise with optional 10 nF bypass capacitor - suitable for ADC references and RF ICs. |
| Logic-compatible enable | EN pin accepts standard 1.8 V/3.3 V logic levels with defined 0.4 V low / 1.2 V high thresholds - no level-shifting needed. |
| Integrated protection | Thermal shutdown (160 °C) + hysteresis (20 °C) and short-circuit current limiting (400 mA) - prevents damage during fault conditions. |
| Wide input range | 1.9 V to 5.5 V operation - supports single-cell Li-ion, Li-poly, or dual-cell alkaline/NiMH battery inputs. |
Applications
| Mobile Phone Baseband Power | Digital Still Camera Sensor Rail |
|---|---|
|
Use Scenario: Powering baseband processor I/O banks requiring clean, regulated 1.8 V from a shared battery rail. IC Role / Device Role / Timing Role: Primary low-noise, low-quiescent LDO delivering stable 1.8 V to interface logic and memory controllers. Use Value: 51 µVRMS noise and 55 dB PSRR prevent digital switching noise from corrupting signal integrity in high-speed data paths. |
Use Scenario: Supplying image sensor analog front-end (AFE) and column ADC circuitry in compact DSC modules. IC Role / Device Role / Timing Role: Dedicated low-noise bias rail isolating sensitive analog circuitry from digital supply transients. Use Value: 100 mV dropout extends usable battery life by maintaining regulation until battery voltage drops to 1.9 V. |
| PDA Application Processor Core | Cordless Phone RF Transceiver |
|
Use Scenario: Providing always-on 1.8 V supply to real-time clock (RTC) and wake-up controller in deep-sleep mode. IC Role / Device Role / Timing Role: Low-quiescent (60 µA typ.) LDO maintaining critical subsystem power while main SoC is powered down. Use Value: <1 µA shutdown current eliminates parasitic drain during extended storage or transport. |
Use Scenario: Biasing RF power amplifier and mixer stages in 2.4 GHz DECT handsets operating from single-cell Li-ion. IC Role / Device Role / Timing Role: Local LDO generating clean 1.8 V from noisy switched-mode charger output or battery with ripple. Use Value: Ceramic-capacitor compatibility (1 µF) enables ultra-compact layout adjacent to RF IC, minimizing loop inductance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Torex XC6219B182MR-G | 180 mA max output; 120 mV dropout at 100 mA; 25 µA IQ; SOT23-5 package only. | Limited to lower current and higher dropout; lacks thermal shutdown hysteresis specification. | Prefer when ultra-low IQ dominates over thermal robustness and full 200 mA capability. |
| Richtek RT9193-18GB | 300 mA max output; 250 mV dropout at 100 mA; 65 µA IQ; includes soft-start; SOT23-5 package. | Higher dropout reduces usable battery range; soft-start adds startup delay not present in LDK120C18R. | Choose only if higher current headroom is required and 100 mV dropout advantage is acceptable to sacrifice. |
Compared with XC6219B182MR-G and RT9193-18GB, LDK120C18R uniquely balances 200 mA delivery, 100 mV dropout, 51 µVRMS noise, and integrated thermal hysteresis - making it optimal for space- and noise-constrained battery-powered systems where runtime and signal integrity are co-prioritized.
Availability
LDK120C18R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and cordless phone systems requiring stable component supply with long-term production continuity through July 2026.
Supply support for LDK120C18R 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, Switzerland, designing and manufacturing analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.
The LDK120 series belongs to ST's precision low-noise LDO portfolio, engineered specifically for battery-powered portable electronics demanding ultra-low IQ, minimal dropout, and ceramic-capacitor compatibility.
FAQ
What is the minimum input voltage required for LDK120C18R to maintain regulation at full 200 mA load?
The minimum input voltage is calculated as VOUT + VDROP = 1.8 V + 300 mV (max dropout at 200 mA, 40–125 °C) = 2.1 V. At 25 °C, typical dropout is 150 mV, so 1.95 V suffices. Operation below 1.9 V input is outside absolute maximum ratings and not functional.
Can LDK120C18R be used with a 1 µF output capacitor without stability issues?
Yes - the datasheet explicitly states compatibility with 1 µF ceramic capacitors (X5R/X7R) and provides stability region plots confirming unconditional stability across 1–22 µF COUT values and ESR <10 Ω. No series resistor or additional compensation is required.
Is the BYP pin mandatory to connect for the LDK120C18R fixed version?
No - the BYP pin is optional for noise reduction. If unused, it must be left floating with no PCB trace or pad connection. Connecting it to GND or VOUT will impair regulation accuracy and noise performance per Table 1 and Figure 23.
Does LDK120C18R support reverse-voltage protection on the IN or OUT pins?
No - the device lacks intrinsic reverse-voltage protection. Absolute maximum ratings specify VIN and VOUT must remain ≥ –0.3 V relative to GND. External protection diodes or MOSFET-based circuits are required if system-level reverse polarity exposure is possible.
LDK120C18R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 5-TSSOP, SC-70-5, SOT-353
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.3V @ 200mA
- Current - Output:
- 200mA
- Current - Quiescent (Iq):
- 60 µA
- Current - Supply (Max):
- 100 µA
- PSRR:
- 55dB (120Hz ~ 10kHz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323-5
LDK120C18R FAQ
1.How can I place an order for LDK120C18R through Aetrix?
Please submit a Request for Quotation (RFQ) for LDK120C18R 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 LDK120C18R reliable?
The price and inventory of LDK120C18R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDK120C18R is usually 5 days.
3.What payment methods are accepted for LDK120C18R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDK120C18R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LDK120C18R?
LDK120C18R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LDK120C18R 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 LDK120C18R?
For technical support, including LDK120C18R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDK120C18R requirements.
6.How does Aetrix verify that LDK120C18R is sourced from the original manufacturer or authorized distributors?
All LDK120C18R 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 LDK120C18R meets industry standards.
7.What is the process for return or replacement of LDK120C18R?
All LDK120C18R units undergo pre-shipment inspection (PSI). If there is an issue with LDK120C18R, 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 LDK120C18R part is unused and in its original packaging.
Return procedure for LDK120C18R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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