TLV743P - 300mA Low-Noise LDO, 1.2uA Iq | Texas Instruments
MPN: TLV743P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.35 | $0.35 |
| 10 | $0.32 | $3.20 |
| 100 | $0.26 | $26.00 |
| 500 | $0.21 | $105.00 |
| 1,000 | $0.18 | $180.00 |
TLV743P Overview
An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable output voltage even when the input voltage is very close to the output voltage. Within the power management IC hierarchy (LDO -> linear regulator -> voltage regulator -> power management IC), the LDO serves as the final low-noise stage, filtering ripple from upstream switching converters before sensitive loads such as MCUs, RF circuits, and sensors.
Key features include 1% typical output accuracy, an active pulldown circuit that quickly discharges the output when the device is disabled, and foldback current control during power up and enabling that limits inrush current. Stability with a small 1 uF output capacitor reduces BOM count and board area, and the very low quiescent current (1.2 uA class) maximizes battery life in always-on designs.
Technically, the TLV743P uses a CMOS architecture that achieves low dropout voltage and extremely low supply current, making it highly efficient for battery-powered applications. The active output pulldown prevents undefined logic states during shutdown, while foldback current control protects both the load and the input supply during startup transients.
Typical applications include portable electronics, wearables, IoT sensor nodes, and battery-powered devices where board space and standby power are critical. The ultra-small X2SON-4 (0.8 x 0.8 mm) package suits densely populated mobile PCBs, while SOT-23-5 offers easy hand assembly.
When designing with the TLV743P, keep the input at least one dropout voltage above the output across all load and temperature conditions, and place the 1 uF output capacitor close to the OUT pin for stability.
Drop-in alternatives for TLV743P — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with TLV743P (same form factor and footprint) — differing in Line/Load Transient, Output Capacitor, Output Current, Output Voltage Options, Packages.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
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TLV74318PDBVR
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TLV713
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View Datasheet →NCP703
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AP2112K-3.3TRG1
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TLV743P Maximum Ratings & Electrical Characteristics
| Output Current | 300 mA |
| Output Accuracy | 1% (typical) |
| Regulator Type | Low-Dropout Linear Regulator (LDO) |
| Output Capacitor | 1 uF minimum (stable with ceramic) |
| Packages | DBV (SOT-23-5), DQN (X2SON-4) |
| Output Discharge | Active pulldown when disabled |
| Current Limit | Foldback current control at power up and enable |
| Output Voltage Options | Fixed options (e.g., TLV74310P, TLV74318P, TLV74333P) |
| Line/Load Transient | Good line and load transient performance |
| Mounting Type | Surface Mount |
TLV743P Pin Configuration
| Pin 1 | IN — Input supply voltage |
| Pin 2 | GND — Ground |
| Pin 3 | EN — Enable input (active high) |
| Pin 4 | NC — No connection (SOT-23-5) |
| Pin 5 | OUT — Regulated output voltage |
Typical Applications
TLV743P is suitable for 6 applications: Portable and Wearable Electronics, IoT Sensor Nodes, MCU and Processor I/O Rails, Post-Regulation After DC-DC Converters, Battery Management Auxiliary Rails, Consumer Audio Accessories.
Portable and Wearable Electronics
The TLV743P fits portable and wearable designs because its quiescent current is in the 1.2 uA class, preserving battery life in always-on duty cycles, while the 300 mA capability covers MCU and radio transmit bursts. The X2SON-4 (0.8 x 0.8 mm) package fits the tight PCB area of smart bands and earbuds. Place the device between the battery/boost rail and the load with a 1 uF ceramic output capacitor; the active pulldown ensures the rail fully discharges when the system sleeps, avoiding leakage into off-state peripherals.
Recommended
IoT Sensor Nodes
Battery-powered IoT sensor nodes spend most of their life in sleep, so regulator quiescent current dominates average draw. The TLV743P's very low Iq and foldback current control during enable limit inrush when the node wakes and powers radios or sensors, protecting small coin cells. Stability with just 1 uF of output capacitance minimizes BOM cost. Typical topology: Li-SOCl2 or LiMnO2 cell feeding the TLV743P, which generates a clean 1.8V-3.3V rail for the MCU and sensor; load transients from radio TX are handled by the 300 mA headroom.
Recommended
MCU and Processor I/O Rails
Microcontroller cores and I/O banks need rails that power down cleanly to avoid latch-up or back-powering. The TLV743P's active pulldown rapidly discharges the output when EN goes low, enforcing a defined off state between power cycles. The 300 mA rating covers typical MSP430, MSPM0, or SimpleLink loads. Place the LDO after a 3.3V or 5V system rail with 1 uF caps on both sides; the foldback current limit softens the startup edge so inrush into decoupling networks does not droop the upstream supply.
Recommended
Post-Regulation After DC-DC Converters
Switching converters introduce output ripple that degrades analog performance. The TLV743P works as a post-regulator stage after a buck converter: its good line transient performance rejects the switching ripple, delivering a quiet rail for ADC references, PLLs, or RF front ends. Pair a TPS62xxx or TPS54xxx buck with the TLV743P, set the LDO dropout headroom to 200-300 mV, and use 1 uF ceramics at both pins. The trade-off is added dropout power loss, acceptable at sub-300 mA loads.
Recommended
Battery Management Auxiliary Rails
In battery chargers and gauging systems, low-power auxiliary rails for the gauge IC, fuel gauge, or protection MCU can be supplied by the TLV743P. Its 1% typical accuracy keeps gauge supply rails within tolerance, and the very low shutdown current means the regulator itself does not drain the pack in storage. Use the EN pin driven by the pack-protection logic so the auxiliary rail discharges through the active pulldown when the pack is disabled, preventing leakage paths through the gauge.
Recommended
Consumer Audio Accessories
True wireless earbuds and small audio accessories require quiet, tiny power for codec and amplifier bias. The TLV743P's low noise CMOS LDO topology and good load transient response supply codec analog rails during dynamic audio playback without audible artifacts, while the X2SON-4 package fits inside earbud shells. Supply the LDO from a Li-ion cell via a small buck, keep dropout headroom around 300 mV, and use the enable pin to mute-power the codec during standby, with the pulldown fully discharging the analog rail.
Recommended
Recommended Products Summary
Engineering reference data for TLV743P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TLV74333PDBVR | TLV713 | NCP703 |
|---|---|---|---|---|
| Package | DBV (SOT-23-5) / DQN (X2SON-4) | SOT-23-5 - same | SOT-23-5 - same | SOT-23-5 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | onsemi |
| Output Current | 300 mA | 300 mA | 300 mA | 300 mA |
Key Differentiators
- Active output pulldown for defined shutdown (vs TLV713)
- Foldback current control at startup (vs AP2112K-3.3TRG1)
- Extremely low quiescent current (vs NCP703)
Design Notes
Place the 1 uF input and 1 uF output ceramic capacitors as close to the IN and OUT pins as possible. For the X2SON-4 package, TI recommends a thermal via pad pattern under the device; follow the datasheet layout example for reliable solder joints on this 0.8 mm package.
Ensure VIN exceeds VOUT by at least the dropout voltage at maximum load and minimum input (e.g., low battery). If VIN-VOUT is large, verify junction temperature: dissipation = (VIN-VOUT) x IOUT. Keep total dissipation within the SOT-23-5 theta_JA limits with standard copper pour.
Do not omit the output capacitor - the TLV743P requires a minimum 1 uF ceramic for stability. When substituting within the TLV743xx family, remember NC pins (e.g., pin 4 on TLV74310PDBVR) may be left floating per the TI E2E forum, but do not use them as tie points.
Compliance Information
Compliance data not present in provided web data. Verify on ti.com for the specific orderable part number (e.g., TLV74333PDBVR).
