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STMicroelectronics LD39020ATPU185R
- Part No.:
- LD39020ATPU185R
- Manufacturer:
- STMicroelectronics
- Package:
- 4-XDFN Exposed Pad
- Datasheet:
-
LD39020ATPU185R.pdf
- Description:
- IC REG LINEAR 1.85V 200MA 4DFN
- Quantity:
- Payment:
- Shipping:
Inventory:9,988
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Product details
Overview
LD39020ATPU185R from STMicroelectronics is a high-accuracy, 200 mA low-dropout linear regulator with 1.85 V fixed output voltage, ±0.5 % tolerance at 25 °C, 200 mV typical dropout at 200 mA, and ultra-low 20 µA quiescent current at no load - designed for power-sensitive battery-operated systems such as mobile phones and digital still cameras.
For engineers reviewing the LD39020ATPU185R datasheet, LD39020ATPU185R pinout, LD39020ATPU185R application, or LD39020ATPU185R equivalent, key selection criteria include output accuracy, thermal shutdown threshold (160 °C), enable logic compatibility (0.4 V low / 1 V high), soft-start timing (100 µs), and ceramic capacitor stability down to 0.47 µF.
Technical Context
The LD39020ATPU185R integrates a bandgap reference, error amplifier, and internal PMOS pass transistor in a feedback loop optimized for low-noise, high-PSRR regulation. Its architecture supports logic-controlled shutdown via the EN pin, delivering sub-0.1 µA standby current when disabled.
It features an internal soft-start circuit that limits inrush current without external components and - in variants with discharge functionality - an optional NMOS discharge switch between VOUT and GND. This specific part (LD39020ATPU185R) does not include the output discharge MOSFET.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output voltage | Fixed 1.85 V ±0.5 % at 25 °C - enables precise biasing of low-voltage logic cores and memory interfaces. |
| Max output current | 200 mA guaranteed - sufficient for powering single-core microcontrollers or sensor subsystems. |
| Dropout voltage | 200 mV typ. at 200 mA - allows operation from 2.05 V input, extending battery runtime in Li-ion or dual-cell alkaline systems. |
| Quiescent current | 20 µA typ. at no load - minimizes standby power loss in always-on sensor nodes or RTC circuits. |
| PSRR | 80 dB @ 1 kHz - suppresses switching noise from adjacent DC-DC converters feeding shared input rails. |
| Operating temperature | −40 °C to +125 °C junction - qualified for automotive cabin and industrial edge computing environments. |
| Enable threshold | VIL = 0.4 V, VIH = 1 V - compatible with 1.8 V and higher GPIO logic families without level-shifting. |
Pinout & Package
LD39020ATPU185R is available in DFN4 1×1 mm (0.37 mm height) and SOT23-5L packages. Both are RoHS-compliant, thermally enhanced surface-mount formats suitable for space-constrained portable designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN (Pin 1, SOT23-5L; Pin 4, DFN4) | Input voltage supply | Accepts 1.5–5.5 V; requires ≥1 µF ceramic decoupling placed adjacent to pin. |
| GND (Pin 2, SOT23-5L; Pin 2, DFN4) | Power ground reference | Common return path for input/output currents; thermal pad (DFN4) must be soldered to PCB ground plane. |
| EN (Pin 3, SOT23-5L; Pin 3, DFN4) | Logic enable control | Active-high; pulls device into <0.1 µA shutdown when driven ≤0.4 V. |
| OUT (Pin 5, SOT23-5L; Pin 1, DFN4) | Regulated output | Delivers stable 1.85 V; requires ≥0.47 µF ceramic capacitor with X5R/X7R dielectric for loop stability. |
| NC (Pin 4, SOT23-5L) | No connect | Not internally bonded - must be left floating or tied to GND per layout best practice. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low dropout | 200 mV typ. at full 200 mA load - enables use with depleting batteries down to ~2.05 V input. |
| Low-noise regulation | 45 µVRMS output noise (10 Hz–100 kHz) - preserves signal integrity in ADC reference or RF bias rails. |
| Internal soft-start | 100 µs controlled ramp-up - prevents input rail sag and avoids false resets during power-up. |
| Thermal & current protection | 160 °C shutdown with 20 °C hysteresis + internal current limiting - ensures robustness under overload or ambient extremes. |
| Ceramic capacitor compatible | Stable with COUT ≥0.47 µF, ESR <15 Ω - eliminates need for costly tantalum or electrolytic capacitors. |
Applications
| Mobile Phone Power Rail | Digital Still Camera Sensor Bias |
|---|---|
Use Scenario: Supplying 1.85 V to image sensor analog front-end and ISP core in compact smartphone modules. IC Role / Device Role / Timing Role: Primary LDO for noise-sensitive analog pixel array and low-jitter clock domain support. Use Value: 80 dB PSRR at 1 kHz rejects noise from baseband processor switching, preserving SNR in low-light capture. |
Use Scenario: Providing clean 1.85 V bias to CMOS image sensor I/O and PLL circuits during burst-mode capture. IC Role / Device Role / Timing Role: Low-noise, fast-response voltage source enabling rapid sensor wake-up and exposure synchronization. Use Value: 100 µs soft-start prevents frame corruption during camera activation; 20 µA quiescent current extends standby time between shots. |
| Tablet Application Processor Core | Cordless Phone Baseband IC |
Use Scenario: Delivering 1.85 V to ARM Cortex-A series CPU core voltage domain in ultra-thin tablets. IC Role / Device Role / Timing Role: Secondary LDO downstream of buck converter, filtering residual ripple before core logic. Use Value: 200 mV dropout allows sustained operation during battery voltage droop under peak CPU load. |
Use Scenario: Powering 1.85 V digital baseband ASIC in DECT cordless handsets operating on two AA cells. IC Role / Device Role / Timing Role: Main system regulator managing dynamic load transients during voice call handshaking and encryption bursts. Use Value: −40 °C to +125 °C rating ensures reliable startup and regulation across indoor/outdoor temperature swings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Torex XC6210B182MR-G | 1.8 V output, ±2 % tolerance, 150 mA max, SOT25 package - lacks thermal shutdown and soft-start. | Suitable only for non-critical, low-transient consumer accessories with relaxed accuracy requirements. | Select only if cost sensitivity outweighs accuracy, safety, and noise performance needs. |
| ROHM BD39020MUV-E2 | 1.85 V output, ±0.5 %, 200 mA, same DFN1006-4 package - includes output discharge MOSFET (not present in LD39020ATPU185R). | Required where rapid VOUT discharge is needed after shutdown (e.g., to meet USB PD reset timing). | Choose only if discharge functionality is mandatory; otherwise LD39020ATPU185R offers identical regulation specs with lower BOM count. |
Compared with XC6210B182MR-G, LD39020ATPU185R delivers tighter output accuracy, higher current capability, and integrated protections; versus BD39020MUV-E2, it omits discharge but reduces complexity and leakage in always-on systems.
Availability
LD39020ATPU185R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and cordless phone systems requiring stable component supply, long-lifecycle support, and automotive-grade thermal reliability.
Supply support for LD39020ATPU185R 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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.
The LD39020 series belongs to ST's high-accuracy, ultra-low-IQ LDO portfolio - engineered specifically for energy-constrained portable electronics demanding precision regulation, minimal standby loss, and small-footprint integration.
FAQ
What is the minimum input voltage required for stable 1.85 V output at 200 mA?
The LD39020ATPU185R requires VIN ≥ VOUT + VDROP = 1.85 V + 0.2 V = 2.05 V for full 200 mA load. At 200 mA and 25 °C, typical dropout is 200 mV; worst-case (−40 °C to +125 °C) is 350 mV, so design margin should assume VIN ≥ 2.2 V for robust operation across temperature.
Can LD39020ATPU185R be used with a 0.22 µF output capacitor?
No - the datasheet specifies a minimum stable output capacitance of 0.47 µF (X5R/X7R ceramic). Using 0.22 µF risks instability, overshoot, or oscillation under load transients, as confirmed by Figure 17's stability boundary. Always adhere to the 0.47–22 µF recommended range.
Does LD39020ATPU185R include the output discharge feature?
No. Per Table 10 in DS9956 Rev 6, LD39020ATPU185R has "No" in the Auto-discharge column. Only variants marked "AD" (e.g., LD39020ADTPU185R) integrate the discharge MOSFET. This part relies on external discharge paths or natural capacitor leakage.
Is the thermal pad on the DFN4 1×1 package electrically connected?
Yes - the thermal pad is internally connected to GND. It must be soldered to a PCB copper pour tied to the system ground plane to ensure proper thermal dissipation and electrical reference integrity. Omitting this connection degrades RthJA by >100 °C/W and risks thermal shutdown under load.
LD39020ATPU185R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 4-XDFN Exposed Pad
- 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):
- 1.85V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.35V @ 200mA
- Current - Output:
- 200mA
- Current - Quiescent (Iq):
- 40 µA
- Current - Supply (Max):
- -
- PSRR:
- 80dB ~ 55dB (1kHz ~ 100kHz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature, Soft Start
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 4-DFN (1x1)
LD39020ATPU185R FAQ
1.How can I place an order for LD39020ATPU185R through Aetrix?
Please submit a Request for Quotation (RFQ) for LD39020ATPU185R 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 LD39020ATPU185R reliable?
The price and inventory of LD39020ATPU185R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD39020ATPU185R is usually 5 days.
3.What payment methods are accepted for LD39020ATPU185R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD39020ATPU185R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LD39020ATPU185R?
LD39020ATPU185R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LD39020ATPU185R 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 LD39020ATPU185R?
For technical support, including LD39020ATPU185R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD39020ATPU185R requirements.
6.How does Aetrix verify that LD39020ATPU185R is sourced from the original manufacturer or authorized distributors?
All LD39020ATPU185R 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 LD39020ATPU185R meets industry standards.
7.What is the process for return or replacement of LD39020ATPU185R?
All LD39020ATPU185R units undergo pre-shipment inspection (PSI). If there is an issue with LD39020ATPU185R, 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 LD39020ATPU185R part is unused and in its original packaging.
Return procedure for LD39020ATPU185R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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