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Texas Instruments REG101UA-2.85/2K5
- Part No.:
- REG101UA-2.85/2K5
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
REG101UA-2.85/2K5.pdf
- Description:
- IC REG LINEAR 2.85V 100MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,918
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Product details
Overview
REG101UA-2.85/2K5 from Texas Instruments is a 100mA, 2.85V fixed-output low-dropout linear regulator using DMOS pass transistor topology. It delivers ultra-low dropout voltage (60mV typ at 100mA), 23µVrms output noise, ±1.5% output accuracy over temperature/load, and operates from 1.8V to 10V input - ideal for battery-powered portable communication devices requiring stable, low-noise bias.
For engineers reviewing the REG101UA-2.85/2K5 datasheet, REG101UA-2.85/2K5 pinout, REG101UA-2.85/2K5 application, or REG101UA-2.85/2K5 equivalent, key selection criteria include dropout performance under full load, noise reduction capability with CNR capacitor, enable control timing, thermal shutdown behavior, and SO-8 package thermal resistance (θJA = 150°C/W).
Technical Context
The REG101UA-2.85/2K5 employs an N-channel DMOS pass element driven by an internal charge pump, enabling gate drive above VIN and achieving DC dropout as low as 60mV at 100mA. Its bandgap reference and error amplifier deliver ±1.5% initial accuracy and <50ppm/°C drift, tested across –40°C to +85°C.
No output capacitor is required for stability - unlike conventional LDOs - and transient response is enhanced via optional 0.01µF noise-reduction capacitor on the NR pin. Enable logic is TTL/CMOS-compatible (VENABLE ≥ 1.8V enables output), with ground current dropping to 10nA in shutdown mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.85V ±1.5% over –40°C to +85°C - ensures precise biasing for 2.8V–3.0V logic rails without external feedback. |
| Dropout Voltage | 60mV typical at 100mA - allows operation with only 2.91V input, maximizing battery runtime in single-cell Li-ion or two-cell alkaline systems. |
| Output Noise | 23µVrms (10Hz–100kHz, no CNR); 7µVrms with 0.01µF CNR - meets low-noise requirements for RF front-ends and precision ADC references. |
| Ground Current | 500µA at 100mA load; 10nA in shutdown - minimizes quiescent power loss during sleep modes in portable equipment. |
| Enable Threshold | VENABLE ≥ 1.8V enables output; ≤0.5V disables - compatible with 1.8V/3.3V microcontroller GPIO without level-shifting. |
| Thermal Protection | Shuts down at TJ ≈ 160°C; resumes at ≈140°C - prevents permanent damage during sustained overload or poor PCB heat sinking. |
| Package | SO-8 (D package) - provides 150°C/W junction-to-ambient thermal resistance and robust solder joint reliability for industrial-grade assembly. |
Pinout & Package
REG101UA-2.85/2K5 is housed in an 8-pin SOIC (D package) with exposed pad not electrically connected. Pin 1 is VIN; pins 7 and 8 are both VIN (must be connected); pin 2 is GND; pin 3 is Enable; pin 4 is VOUT; pin 5 is NR (Noise Reduction); pins 6 and 8 are NC (no connect). The NR pin accepts a 0.01µF capacitor to ground for noise reduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pins 1, 7, 8) | Input supply connection | All three pins must be connected to input rail; parallel routing reduces trace resistance and improves current handling. |
| GND (Pin 2) | Power ground reference | Primary return path for load current and internal circuitry; requires low-impedance PCB plane connection. |
| Enable (Pin 3) | Active-high output control | Drives output ON/OFF; high-impedance when floating - pull-down recommended for default-off behavior. |
| VOUT (Pin 4) | Regulated output terminal | Delivers 2.85V to load; low ESR ceramic capacitor (0.1µF) recommended on input, not required on output. |
| NR (Pin 5) | Noise reduction filter node | Accepts 0.01µF capacitor to ground to reduce reference noise contribution; not present on adjustable versions. |
| NC (Pins 6, 8) | No-connect terminals | Internally unconnected; must remain unconnected on PCB to avoid parasitic coupling or latch-up risk. |
Key Features
| Feature | Design Value |
|---|---|
| DMOS pass transistor | Enables 60mV dropout at full 100mA load - extends usable battery voltage range beyond PNP-based LDOs. |
| No output capacitor required | Stable with zero COUT; eliminates need for costly low-ESR capacitors and simplifies layout in space-constrained designs. |
| Foldback current limit | Reduces short-circuit current to ~60mA - limits power dissipation during fault conditions and protects downstream circuitry. |
| Ultra-low noise (23µVrms) | Meets stringent analog/RF supply requirements without external filtering - critical for sensitive receivers and PLL power rails. |
| Thermal shutdown with hysteresis | Auto-recovers at ~140°C after shutdown at ~160°C - enables self-resetting protection without system-level intervention. |
Applications
| Portable Communication Devices | Battery-Powered Equipment |
|---|---|
Use Scenario: Powering RF transceivers and baseband processors in handheld radios and IoT edge nodes. IC Role / Device Role / Timing Role: Primary 2.85V LDO supplying clean, regulated voltage to analog front-end and digital core blocks. Use Value: 23µVrms noise and fast transient response prevent signal distortion and data corruption during burst transmission. | Use Scenario: Providing stable bias to microcontrollers and sensors in wireless sensor nodes operating from coin cells or AA batteries. IC Role / Device Role / Timing Role: Main system regulator delivering 2.85V to MCU I/O and ADC reference, with enable pin synchronized to wake/sleep cycles. Use Value: 10nA shutdown current and 60mV dropout extend operational life by >20% compared to standard LDOs in intermittent-use applications. |
| Personal Digital Assistants | Barcode Scanners |
Use Scenario: Supplying 2.85V to touch controller ICs and display interface logic in legacy PDAs with tight thermal envelopes. IC Role / Device Role / Timing Role: Low-noise, thermally robust regulator for mixed-signal subsystems where EMI sensitivity and board area are critical. Use Value: SO-8 package with 150°C/W θJA and foldback current limiting ensure reliable operation without heatsinking in sealed enclosures. | Use Scenario: Powering laser diode drivers and CMOS image sensors in handheld barcode scanners subject to mechanical shock and variable ambient temperature. IC Role / Device Role / Timing Role: Primary 2.85V supply enabling rapid enable/disable sequencing during scan trigger events. Use Value: 1.5ms enable time and 200µs disable time support sub-100ms scan cycle timing while maintaining regulation during dynamic load steps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-noise, fixed-output LDO applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLC7701CP | Higher dropout (250mV @ 100mA), higher noise (45µVrms), no NR pin, TO-92 package | Limited to low-power, non-portable applications due to thermal and noise constraints | Select only if cost is primary concern and 2.85V accuracy ±3% is acceptable. |
| LP2985AIM5-2.85/NOPB | Lower max current (150mA), 65µVrms noise, requires 1µF min COUT, SOT-23-5 package | Not suitable for noise-sensitive RF sections; better for general-purpose digital loads | Choose when board space is constrained and noise below 10µVrms is unnecessary. |
Compared with TLC7701CP and LP2985AIM5-2.85/NOPB, REG101UA-2.85/2K5 uniquely combines ultra-low dropout (60mV), industry-leading 23µVrms noise, and SO-8 thermal performance - making it the only option qualified for high-reliability portable RF and precision analog applications demanding simultaneous low noise, low headroom, and robust thermal management.
Availability
REG101UA-2.85/2K5 is available at Aetrix Electronics and suitable for portable communication devices, battery-powered instrumentation, and barcode scanning systems requiring stable component supply with guaranteed long-term availability and RoHS-compliant green packaging.
Supply support for REG101UA-2.85/2K5 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 leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in power management IC design.
The REG101 family was engineered specifically for portable and battery-critical applications requiring ultra-low dropout, minimal quiescent current, and exceptional noise performance - targeting communications, medical, and industrial edge devices.
FAQ
What is the maximum input voltage rating for REG101UA-2.85/2K5?
The absolute maximum input voltage for REG101UA-2.85/2K5 is 12V, but the specified operating input range is 1.8V to 10V. Operation above 10V may cause parametric degradation or damage. For reliable 2.85V regulation, VIN must exceed VOUT + VDROP (≥2.91V), with optimal performance between 3.0V and 6.0V to balance efficiency and thermal rise.
Does REG101UA-2.85/2K5 require an output capacitor for stability?
No, REG101UA-2.85/2K5 does not require an output capacitor for stability - a key advantage of its DMOS topology. However, adding a 0.1µF to 10µF ceramic capacitor improves transient response and reduces output impedance at high frequencies. Stability is maintained across all capacitor types and values up to 10µF or more.
How does the NR pin function on REG101UA-2.85/2K5?
The NR pin on REG101UA-2.85/2K5 connects to the internal bandgap reference node. Adding a 0.01µF capacitor from NR to GND forms a low-pass filter that reduces reference noise, lowering total output noise from 23µVrms to 7µVrms (10Hz–100kHz). This pin is absent on adjustable versions and must not be left floating - it must be either bypassed or tied directly to GND if unused.
What is the thermal shutdown behavior of REG101UA-2.85/2K5?
REG101UA-2.85/2K5 enters thermal shutdown at approximately 160°C junction temperature and automatically recovers when junction temperature falls to ~140°C. This hysteresis prevents oscillation near trip point. During shutdown, output is disabled and ground current drops to ~10nA. Continuous cycling indicates inadequate PCB copper area or excessive power dissipation - design should limit TJ to ≤125°C for reliability.
Can REG101UA-2.85/2K5 be used in automotive applications?
REG101UA-2.85/2K5 is specified for –40°C to +85°C operating temperature and is not AEC-Q100 qualified. While it may function in under-hood environments with sufficient derating and thermal margin, Texas Instruments does not guarantee automotive-grade reliability or qualification for this part. For automotive use, consider TI's TPS7A series or other AEC-Q100-certified LDOs instead of REG101UA-2.85/2K5.
REG101UA-2.85/2K5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 10V
- Voltage - Output (Min/Fixed):
- 2.85V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.13V @ 100mA
- Current - Output:
- 100mA
- Current - Quiescent (Iq):
- 500 µA
- Current - Supply (Max):
- 650 µA
- PSRR:
- 65dB (120Hz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
REG101UA-2.85/2K5 FAQ
1.How can I place an order for REG101UA-2.85/2K5 through Aetrix?
Please submit a Request for Quotation (RFQ) for REG101UA-2.85/2K5 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 REG101UA-2.85/2K5 reliable?
The price and inventory of REG101UA-2.85/2K5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for REG101UA-2.85/2K5 is usually 5 days.
3.What payment methods are accepted for REG101UA-2.85/2K5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for REG101UA-2.85/2K5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for REG101UA-2.85/2K5?
REG101UA-2.85/2K5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your REG101UA-2.85/2K5 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 REG101UA-2.85/2K5?
For technical support, including REG101UA-2.85/2K5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your REG101UA-2.85/2K5 requirements.
6.How does Aetrix verify that REG101UA-2.85/2K5 is sourced from the original manufacturer or authorized distributors?
All REG101UA-2.85/2K5 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 REG101UA-2.85/2K5 meets industry standards.
7.What is the process for return or replacement of REG101UA-2.85/2K5?
All REG101UA-2.85/2K5 units undergo pre-shipment inspection (PSI). If there is an issue with REG101UA-2.85/2K5, 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 REG101UA-2.85/2K5 part is unused and in its original packaging.
Return procedure for REG101UA-2.85/2K5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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