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Texas Instruments REG71055DDCT
- Part No.:
- REG71055DDCT
- Manufacturer:
- Texas Instruments
- Package:
- SOT-23-6 Thin, TSOT-23-6
- Datasheet:
-
REG71055DDCT.pdf
- Description:
- IC REG CHRG PUMP 5.5V 60MA SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:3,346
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Product details
Overview
REG71055DDCT from Texas Instruments is a fixed 5.5 V output, buck-boost switched-capacitor DC/DC converter in SOT-23-6 package. It operates across 3 V to 5.5 V input, delivers up to 30 mA regulated output, achieves ≤35 mVPP ripple at 30 mA, and maintains regulation whether input is above or below output voltage-ideal for single-cell Li-ion or multi-cell alkaline/nickel-based battery-powered SIM cards and smart card readers.
For engineers reviewing the REG71055DDCT datasheet, REG71055DDCT pinout, REG71055DDCT application, or REG71055DDCT equivalent, key selection criteria include its automatic step-up/step-down operation without inductors, 1 MHz internal oscillator enabling 0.22 µF pump capacitor use, thermal/current protection, and compatibility with low-ESR ceramic capacitors for minimal board space.
Technical Context
The REG71055DDCT uses charge-pump topology with integrated FETs to switch between buck (VIN > VOUT) and boost (VIN < VOUT) modes automatically-no external mode control required. Its 1 MHz oscillator drives flying capacitor CPUMP to generate regulated 5.5 V output while maintaining low input current ripple and high efficiency across wide VIN/VOUT differentials.
Internal protection includes thermal shutdown at 160°C with 140°C hysteresis and current limiting to 100 mA short-circuit output. Quiescent current is 65 µA typical under load and drops to 0.01 µA in shutdown mode, enabled via logic-compatible EN pin with 1.3 V threshold.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.5 V ±5% (5.2–5.8 V), stable over 3 V ≤ VIN ≤ 5.5 V and 0–30 mA load |
| Input Voltage Range | 3 V to 5.5 V (tested startup), supports single-cell Li-ion and 2–3 cell alkaline/nickel chemistries |
| Max Output Current | 30 mA continuous (60 mA peak), sufficient for SIM card power rails and white LED biasing |
| Output Ripple | ≤35 mVPP at 30 mA, achieved with 2.2 µF ceramic COUT and 0.22 µF CPUMP |
| Quiescent Current | 65 µA typical at no load, enabling long battery life in always-on portable devices |
| Shutdown Current | 0.01 µA typical, reducing system standby power to near-zero when EN = low |
| Oscillator Frequency | 1 MHz fixed, allowing compact 0.22 µF flying capacitor and minimizing EMI |
Pinout & Package
SOT-23-6 (DDC) package, 2.90 mm × 1.60 mm body size, exposed thermal pad not present in DDC variant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VOUT | Regulated output supply | Delivers fixed 5.5 V to load; requires 2.2 µF ceramic capacitor to GND for stability and low ripple |
| GND | Power ground reference | Common return path for input, output, and pump circuits; must be low-impedance for noise control |
| Enable | Digital enable/disable control | Active-high logic input (1.3 V threshold); pulls low to enter 0.01 µA shutdown mode |
| VIN | Unregulated input supply | Accepts 3–5.5 V source; connects to 2.2 µF input capacitor to suppress peak current transients |
| Cpump− | Flying capacitor negative terminal | Connects to one side of 0.22 µF ceramic flying capacitor used in charge-transfer cycle |
| Cpump+ | Flying capacitor positive terminal | Connects to other side of 0.22 µF flying capacitor; alternates polarity during switching phases |
Key Features
| Feature | Design Value |
|---|---|
| Automatic buck-boost operation | Switches seamlessly between step-down and step-up modes without external control-maintains 5.5 V regulation even as battery discharges from 5.5 V to 3 V |
| No inductor required | Uses only three external ceramic capacitors (CIN, COUT, CPUMP), eliminating magnetic components, EMI filters, and PCB area typically needed for inductive DC/DC converters |
| Low input current ripple | Peak input current limited internally, reducing stress on battery and input capacitance requirements-enables use of smaller CIN |
| Thermal and current protection | Shuts down at 160°C junction temperature and limits short-circuit current to ~100 mA, preventing damage during fault conditions |
| 1 MHz fixed-frequency operation | Enables use of tiny 0.22 µF flying capacitor and 2.2 µF input/output ceramics-reduces BOM cost and footprint vs lower-frequency charge pumps |
Applications
| Smart Card Readers | SIM Card Power Supply |
|---|---|
Use Scenario: Powering ISO 7816-compliant contact smart cards in handheld POS terminals or secure authentication devices. IC Role / Device Role / Timing Role: Provides stable 5.5 V supply independent of varying battery voltage (3–5.5 V), meeting card interface voltage tolerance and timing requirements. Use Value: Eliminates need for separate LDO or inductor-based regulator; enables direct battery-to-card power with <35 mVPP ripple and <100 µA quiescent draw in sleep mode. |
Use Scenario: Delivering regulated 5.5 V to GSM/UMTS/LTE SIM modules in mobile handsets and IoT trackers. IC Role / Device Role / Timing Role: Acts as primary SIM supply rail generator, supporting hot-swap insertion and dynamic voltage scaling during RF transmission bursts. Use Value: Maintains regulation during rapid battery sag (e.g., 4.2 V → 3.3 V under load), ensuring SIM reset immunity and data integrity without external supervision. |
| White LED Backlight Driver | Handheld Device Core Logic Supply |
Use Scenario: Biasing parallel white LEDs (3.3–4.2 V forward) in small displays for barcode scanners or medical handhelds. IC Role / Device Role / Timing Role: Supplies constant 5.5 V to LED current-source ICs or resistor-limited strings, compensating for battery voltage decay during discharge. Use Value: Delivers consistent LED brightness across full battery range (3–5.5 V input) with no visible flicker due to ≤35 mVPP output ripple. |
Use Scenario: Powering low-power microcontrollers (e.g., MSP430, nRF52) and sensors in battery-operated portable instruments. IC Role / Device Role / Timing Role: Generates clean 5.5 V rail for analog front-ends and digital I/O, coexisting with ultra-low-power sleep states. Use Value: Achieves 0.01 µA shutdown current when MCU enters deep sleep-extending battery life beyond 1 year in intermittent-use applications. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck-boost charge pump applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| REG71050DDCT | Fixed 5.0 V output (vs 5.5 V); identical pinout, package, and electrical specs otherwise | Suitable where 5.0 V is required by downstream logic or legacy interface standards | Select REG71050DDCT only if system-level voltage margin allows 0.5 V lower output; same layout and BOM except for output capacitor rating |
| MAX680ESA+ | Fixed ±5 V dual-output charge pump; requires two external 10 µF capacitors; no shutdown pin; 100 kHz oscillator | Used in dual-rail analog systems (e.g., op-amp biasing), not single-rail digital loads | Choose MAX680ESA+ only for bipolar supply needs; incompatible pinout and higher ripple (>100 mVPP) makes it unsuitable as drop-in replacement |
Compared with REG71055DDCT, REG71050DDCT offers identical form-factor and protection features but targets 5.0 V systems, while MAX680ESA+ serves dual-rail analog applications with fundamentally different architecture, layout, and performance trade-offs-neither is pin-compatible nor functionally interchangeable without redesign.
Availability
REG71055DDCT is available at Aetrix Electronics and suitable for smart card readers, SIM card power supplies, and handheld device core logic requiring stable component supply, RoHS-compliant packaging, and long-term industrial lifecycle support.
Supply support for REG71055DDCT 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 power management technologies, with decades of expertise in precision power conversion and low-power design.
The REG710 family was engineered specifically for battery-powered portable electronics needing compact, inductorless voltage regulation-targeting applications like SIM cards, smart cards, and LCD backlighting where board space and EMI are critical constraints.
FAQ
What is the minimum input voltage required for REG71055DDCT to start up and regulate?
The REG71055DDCT requires a minimum input voltage of 3 V to initiate startup and maintain regulation at its nominal 5.5 V output. This is specified in the Recommended Operating Conditions table under "Tested Startup" for the REG71055 variant. Below 3 V, the device may not achieve or sustain regulation, though it remains functional in shutdown mode if EN is low.
Can REG71055DDCT operate with input voltage equal to output voltage (VIN = VOUT = 5.5 V)?
Yes, the REG71055DDCT supports VIN = VOUT operation. Its automatic buck-boost architecture transitions smoothly between modes: when VIN ≥ VOUT, it operates in step-down (buck) mode using Q4 conduction and Q2 switching; when VIN < VOUT, it switches to step-up (boost) mode. At VIN = 5.5 V, it regulates stably in buck mode with high efficiency.
What external capacitors are mandatory for stable operation of REG71055DDCT?
Three ceramic capacitors are mandatory: 2.2 µF input capacitor (CIN) between VIN and GND, 2.2 µF output capacitor (COUT) between VOUT and GND, and 0.22 µF flying capacitor (CPUMP) between Cpump+ and Cpump−. All must be X7R/X5R dielectric, surface-mount types; tantalum or leaded capacitors increase ripple and degrade performance.
Does REG71055DDCT require a specific PCB layout to meet ripple and thermal specifications?
Yes. To achieve ≤35 mVPP ripple and safe thermal operation, CIN, COUT, and CPUMP must be placed within 2 mm of their respective pins with short, wide traces. The GND connection must be a low-impedance plane; thermal dissipation relies on copper area under the SOT-23-6 body-not an exposed pad, as DDC package lacks one.
How does the Enable pin behavior affect REG71055DDCT's output during shutdown?
When the Enable pin is pulled low (<0.4 V), REG71055DDCT enters shutdown mode: output is actively disconnected from input, quiescent current drops to 0.01 µA typical, and VOUT decays passively through the load. The output does not remain regulated or latched-it floats downward unless externally held. Re-enabling restores regulation within microseconds.
REG71055DDCT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SOT-23-6 Thin, TSOT-23-6
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Charge Pump
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 5.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 60mA
- Frequency - Switching:
- 1MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-THIN
REG71055DDCT FAQ
1.How can I place an order for REG71055DDCT through Aetrix?
Please submit a Request for Quotation (RFQ) for REG71055DDCT 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 REG71055DDCT reliable?
The price and inventory of REG71055DDCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for REG71055DDCT is usually 5 days.
3.What payment methods are accepted for REG71055DDCT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for REG71055DDCT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for REG71055DDCT?
REG71055DDCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your REG71055DDCT 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 REG71055DDCT?
For technical support, including REG71055DDCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your REG71055DDCT requirements.
6.How does Aetrix verify that REG71055DDCT is sourced from the original manufacturer or authorized distributors?
All REG71055DDCT 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 REG71055DDCT meets industry standards.
7.What is the process for return or replacement of REG71055DDCT?
All REG71055DDCT units undergo pre-shipment inspection (PSI). If there is an issue with REG71055DDCT, 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 REG71055DDCT part is unused and in its original packaging.
Return procedure for REG71055DDCT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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