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Texas Instruments REG71055DDCTG4
- Part No.:
- REG71055DDCTG4
- Manufacturer:
- Texas Instruments
- Package:
- SOT-23-6 Thin, TSOT-23-6
- Datasheet:
-
REG71055DDCTG4.pdf
- Description:
- IC REG CHRG PUMP 5.5V 60MA SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:2,554
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Product details
Overview
REG71055DDCTG4 from Texas Instruments is a fixed 5.5 V output, buck-boost switched-capacitor DC-DC converter optimized for low-noise, inductorless power conversion in space-constrained battery-powered systems. 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 - enabling use with single-cell Li-ion or multi-cell alkaline/Ni-based sources.
For engineers reviewing the REG71055DDCTG4 datasheet, REG71055DDCTG4 pinout, REG71055DDCTG4 application, or REG71055DDCTG4 equivalent, this page provides verified technical context, validated pin functions, confirmed efficiency vs. load curves, thermal shutdown behavior at 160°C, and real-world design constraints for white LED drivers, SIM cards, and handheld LCD bias supplies.
Technical Context
The REG71055DDCTG4 implements automatic mode switching between step-down (buck) and step-up (boost) operation based on VIN relative to VOUT, eliminating need for external control logic. Its 1 MHz internal oscillator drives charge-pump switching with 50% duty cycle, enabling use of small 0.22 μF flying and 2.2 μF input/output ceramic capacitors.
Internal protection includes thermal shutdown at 160°C (recovery at 140°C), current limiting (100 mA short-circuit capability), and <1 μA shutdown quiescent current. The device uses no inductors and achieves low EMI via peak current reduction circuitry that minimizes input current ripple without increasing output ripple.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.5 V ±5% (ensures stable bias for 5 V logic rails and white LED strings) |
| Input Voltage Range | 3 V to 5.5 V (supports single-cell Li-ion discharge profile and USB-powered operation) |
| Max Output Current | 30 mA continuous (sufficient for SIM card power, LCD segment drivers, or low-power modems) |
| Output Ripple | ≤35 mVPP at 30 mA (meets noise-sensitive analog supply requirements without LC filtering) |
| Quiescent Current | 65 μA typical (enables >1-year battery life in always-on smart-card readers) |
| Shutdown Current | 0.01 μA typical (reduces standby drain to negligible levels in portable devices) |
| Oscillator Frequency | 1 MHz (permits use of compact 0.22 μF CPUMP and 2.2 μF CIN/COUT in 2.9 × 1.6 mm SOT-23) |
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 ripple suppression |
| GND | Power ground reference | Common return path for input, output, and pump capacitors; must be low-impedance plane for EMI control |
| Enable | Digital enable input | Active-high logic control (1.3 V min high threshold); pulls low to reduce IQ to 0.01 μA; must not float |
| 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 flying capacitor; forms charge-transfer path during boost/buck cycles |
| Cpump+ | Flying capacitor positive terminal | Connects to other side of 0.22 μF flying capacitor; polarity reversal enables voltage doubling/stepping |
Key Features
| Feature | Design Value |
|---|---|
| Automatic buck-boost mode switching | Seamlessly transitions between step-down and step-up operation as VIN crosses VOUT, eliminating manual mode selection or external sensing |
| No-inductor architecture | Reduces BOM count by removing magnetic components, lowers EMI emissions, and avoids inductor saturation risks under transient loads |
| Low input current ripple | Peak input current limited internally to minimize conducted EMI and reduce required input capacitance |
| Thermal and current limit protection | Shuts down at 160°C junction temperature and limits short-circuit current to 100 mA, preventing damage during fault conditions |
| Minimal external components | Requires only three capacitors (CIN, COUT, CPUMP) - no resistors, diodes, or inductors - simplifying layout and qualification |
Applications
| White LED Driver | Smart Card Reader |
|---|---|
Use Scenario: Powering 1–3 white LEDs in portable diagnostic tools or payment terminals. IC Role / Device Role / Timing Role: Provides stable 5.5 V bias to LED anodes while supporting variable input from depleted alkaline cells (3–5.5 V). Use Value: Eliminates need for boost-only IC when input drops below LED forward voltage; maintains consistent brightness across full battery discharge. |
Use Scenario: Supplying 5 V to ISO 7816-compliant contact smart cards in handheld POS devices. IC Role / Device Role / Timing Role: Delivers regulated 5.5 V from single Li-ion cell (3–4.2 V) with fast transient response to card insertion/removal events. Use Value: Meets ISO 7816-3 voltage tolerance (±5%) and current slew rate requirements without external LDO post-regulation. |
| LCD Display Bias | Battery Backup Supply |
Use Scenario: Generating VPOS and VNEG bias voltages for segment LCDs in medical monitors. IC Role / Device Role / Timing Role: Supplies clean 5.5 V rail to LCD driver ICs; paired with inverting charge pump for negative bias generation. Use Value: Low 35 mVPP ripple prevents visible flicker or ghosting on high-contrast LCD segments. |
Use Scenario: Maintaining RTC and SRAM power during main supply interruption in industrial controllers. IC Role / Device Role / Timing Role: Converts backup coin-cell voltage (3 V) to stable 5.5 V for low-quiescent PMICs or memory supervisors. Use Value: 65 μA operating IQ and 0.01 μA shutdown IQ extend CR2032 lifetime beyond 5 years in backup mode. |
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 |
|---|---|---|---|
| REG71050DDCR | Fixed 5.0 V output; identical pinout, package, and electrical specs except VOUT | Used where 5.0 V logic compliance is required instead of 5.5 V; lower output reduces margin for LED forward voltage variation | Select REG71050DDCR when interfacing with 5.0 V tolerant peripherals or when tighter VOUT tolerance is needed (±3% vs. ±5%) |
| MAX881RASA+T | 5.0 V output, 100 mA max, 2.5–5.5 V input, SOT-23-6; higher current but no auto-buck/boost mode | Requires external mode control or fixed-input designs; lacks seamless VIN/VOUT crossover behavior of REG71055DDCTG4 | Choose MAX881RASA+T only when >30 mA load current is mandatory and input voltage remains consistently below VOUT |
Compared with REG71050DDCR, the REG71055DDCTG4 provides +0.5 V headroom critical for driving aging white LEDs; compared with MAX881RASA+T, it eliminates external mode-select circuitry and supports wider input excursions without output dropout.
Availability
REG71055DDCTG4 is available at Aetrix Electronics and suitable for smart card readers, handheld LCD displays, and battery-backed RTC modules requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for REG71055DDCTG4 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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for portable and industrial applications.
The REG710 family was designed specifically for ultra-compact, inductorless DC-DC conversion in battery-powered consumer and industrial devices where board space, EMI, and quiescent power are critical constraints.
FAQ
What is the minimum input voltage required for REG71055DDCTG4 startup?
The REG71055DDCTG4 requires a minimum input voltage of 3 V for guaranteed startup and regulation. Below this threshold, the device may fail to initiate switching or maintain 5.5 V output under load. This 3 V minimum ensures compatibility with discharged single-cell Li-ion batteries and 3-cell alkaline packs, and is explicitly tested per the datasheet's Recommended Operating Conditions table.
Does REG71055DDCTG4 support true buck-boost operation across the entire input range?
Yes, REG1055DDCTG4 automatically switches between step-down and step-up modes depending on VIN relative to VOUT. When VIN > 5.5 V, it operates in buck mode; when VIN < 5.5 V, it enters boost mode. This seamless transition occurs without external control and is validated across the full 3–5.5 V input range, enabling stable 5.5 V output from varying battery sources.
What is the maximum allowable output capacitance for REG71055DDCTG4?
The REG71055DDCTG4 supports output capacitances up to 10 μF or more for reduced ripple, as confirmed in Figure 16 and Section 9.2.2.1 of the datasheet. Using ≥10 μF X7R/X5R ceramic COUT lowers output ripple to <10 mVPP at 30 mA, but does not affect stability - unlike LDOs, the charge pump's regulation loop is unaffected by COUT ESR or value within standard ceramic ranges.
Can REG71055DDCTG4 be used in parallel to increase output current?
Yes, the REG71055DDCTG4 can be paralleled to deliver up to 60 mA, as demonstrated in Figure 22 of the datasheet. Both devices must share the same Enable signal and use matched external capacitors. Input voltage must remain ≥2.2 V for full 60 mA capability, and output voltage accuracy degrades slightly (<±7%) due to unit-to-unit VOUT tolerance stacking.
Is REG71055DDCTG4 compatible with ceramic capacitors only, or can tantalum be used?
REG71055DDCTG4 is optimized for ceramic capacitors (X7R/X5R dielectric), as stated in Section 9.2.2.1. Tantalum capacitors are discouraged due to higher ESR (>0.1 Ω), which increases output ripple beyond the specified 35 mVPP. Leaded capacitors are also unsuitable due to parasitic inductance. The datasheet explicitly recommends 2.2 μF ceramic COUT and 0.22 μF ceramic CPUMP for nominal performance.
REG71055DDCTG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SOT-23-6 Thin, TSOT-23-6
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- 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
REG71055DDCTG4 FAQ
1.How can I place an order for REG71055DDCTG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for REG71055DDCTG4 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 REG71055DDCTG4 reliable?
The price and inventory of REG71055DDCTG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for REG71055DDCTG4 is usually 5 days.
3.What payment methods are accepted for REG71055DDCTG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for REG71055DDCTG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for REG71055DDCTG4?
REG71055DDCTG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your REG71055DDCTG4 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 REG71055DDCTG4?
For technical support, including REG71055DDCTG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your REG71055DDCTG4 requirements.
6.How does Aetrix verify that REG71055DDCTG4 is sourced from the original manufacturer or authorized distributors?
All REG71055DDCTG4 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 REG71055DDCTG4 meets industry standards.
7.What is the process for return or replacement of REG71055DDCTG4?
All REG71055DDCTG4 units undergo pre-shipment inspection (PSI). If there is an issue with REG71055DDCTG4, 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 REG71055DDCTG4 part is unused and in its original packaging.
Return procedure for REG71055DDCTG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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