TPS7A7001DDAR

The TPS7A7001 is a high-performance positive-voltage LDO regulator from TI designed for applications requiring very low input voltage and very low dropout at up to 2 A. The device operates with input voltage as low as 1.425 V, making it suitable for low-voltage rails derived from single-cell Li-ion or point-of-load converters. The output voltage is adjustable from 0.5 V using an external resistor divider, with a 0.5-V internal reference.

The ultra-low dropout voltage (200 mV typical at 1 A, 380 mV max at 2 A) enables efficient regulation where VOUT is close to VIN, minimizing power dissipation. The enable (EN) pin provides on/off control with only 1-µA quiescent current in shutdown, suitable for power-sequencing and standby modes.

The HSOIC-8 PowerPAD package (DDA) provides a low thermal resistance of 46.4°C/W junction-to-ambient when soldered to a PCB with thermal vias. This allows the device to dissipate up to 2 W in typical PCB configurations without overheating, sufficient for 2-A loads with up to 1 V of input-to-output differential.

The internal current limit and thermal shutdown protect the device during fault conditions. The 2% output accuracy over line, load, and temperature ensures stable supply rails for sensitive loads such as FPGAs, DSPs, and RF sections. The minimum 4.7-µF output capacitor (ceramic) ensures stability with low ESR.

The TPS7A7001 complements TI’s lower-current LDO families (TPS736xx, TPS737xx) by providing higher output current while maintaining low dropout, filling the gap between 1-A LDOs and switching regulators for mid-power POL applications.

**Pass Transistor Regulation:** The TPS7A7001 uses a P-channel MOSFET pass transistor driven by an error amplifier. The error amplifier compares a fraction of the output voltage (via the external R1/R2 divider) with the internal 0.5-V bandgap reference. When VOUT drops below the target, the error amplifier drives the PMOS gate harder, reducing RDS(on) and increasing output current. When VOUT rises above the target, the gate drive reduces, increasing RDS(on) and decreasing output current.

**Dropout Operation:** In dropout, the PMOS pass transistor is fully enhanced (gate driven to near ground). The dropout voltage equals ID x RDS(on) of the fully-enhanced PMOS. The low 200-mV dropout at 1 A reflects the low channel resistance of the large PMOS device.

**Enable and Shutdown:** The EN pin controls an internal bias circuit. When EN is below the threshold (~1.2 V), all internal bias is disabled, and the output is high-impedance. Ground current drops to 1 µA maximum. When EN is above the threshold, the regulator operates normally.

**Protection Circuits:** The current limit circuit senses output current and clamps it to a safe level (typically 2.8 A) during overload. The thermal shutdown disables the output when junction temperature exceeds ~160°C, with ~20°C hysteresis to prevent oscillation.