Texas Instruments TPS75533KC

Overview

TPS75533KC from Texas Instruments is a 5-A, 3.3-V fixed-output low-dropout (LDO) voltage regulator in TO-220 (KC) package with integrated open-drain power-good (PG) output, 250 mV typical dropout at 5 A, and 125 µA typical quiescent current. It delivers stable 3.3-V rail for high-current digital loads such as DSPs, FPGAs, and microcontrollers in industrial power management systems.

For engineers reviewing the TPS75533KC datasheet, TPS75533KC pinout, TPS75533KC application, or TPS75533KC equivalent, key selection criteria include dropout performance under full 5-A load, thermal behavior in TO-220 mounting, PG timing thresholds (91% VO trip), and compatibility with 100-µF ceramic+bulk output capacitance for fast transient response.

Technical Context

The TPS75533KC uses a PMOS pass element enabling ultra-low dropout (250 mV @ 5 A) and load-independent quiescent current (125 µA). Its internal bandgap reference (1.22 V) feeds an error amplifier controlling the pass device to maintain ±3% output accuracy over line, load, and temperature (−40°C to 125°C).

It integrates UVLO (2.2–2.75 V), thermal shutdown (150°C), and current limiting (~10 A). The EN pin enables active-low logic control with <1 µA standby current; FB/PG serves dual role-feedback input for adjustable variants, open-drain PG output (active-low, 0.15–0.4 V low-level) for fixed versions like TPS75533KC.

Key Specifications

Pinout & Package

TPS75533KC is housed in a 5-pin TO-220 (KC) package with exposed tab electrically connected to GND. Thermal resistance is R_θJC = 2°C/W and R_θJA = 58.7°C/W (free-standing, no heatsink). Mounting requires mechanical attachment to heatsink via tab for >2 W dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPS75533KTT, the TPS75533KC offers identical regulation performance but higher R_θJA, requiring mechanical heatsinking above ~2 W; versus TPS75733KC, it trades 2-A extra current capacity and integrated PG for slightly higher dropout and quiescent current - making it the sole choice for 5-A, PG-enabled, through-hole 3.3-V LDO applications.

Availability

TPS75533KC is available at Aetrix Electronics and suitable for industrial PLCs, FPGA power delivery, medical sensor interfaces, and automotive infotainment head units requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TPS75533KC 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 ICs, with decades of expertise in high-reliability linear regulators and automotive-grade power solutions.

The TPS755xx family was designed specifically for high-current, low-noise, fixed-output LDO applications in industrial automation, medical instrumentation, and communications infrastructure - emphasizing thermal robustness, fast transient response, and integrated power monitoring.

FAQ

What is the maximum continuous output current of the TPS75533KC?

The TPS75533KC delivers up to 5 A of continuous output current under specified thermal conditions (T_J ≤ 125°C). Internal current limiting activates at approximately 10 A to protect the device during overload or short-circuit events. Sustained operation at 5 A requires adequate heatsinking - for example, a TO-220-mounted TPS75533KC dissipating 2.4 W (e.g., 4.3 V_IN → 3.3 V_OUT) needs R_θJA ≤ 29°C/W, achievable with a 22°C/W heatsink at 55°C ambient.

How does the power-good (PG) function work on the TPS75533KC?

The TPS75533KC's PG pin is an open-drain, active-low output that signals valid regulation: it pulls low when V_OUT reaches ≥91% of 3.3 V (≈3.003 V) and releases high-impedance when V_OUT drops ≤89% (≈2.937 V). An external pullup resistor (e.g., 10 kΩ to 3.3 V) is mandatory. This hysteresis prevents chatter during marginal conditions and enables reliable power-on reset for MCUs or FPGAs interfacing with the TPS75533KC.

Can the TPS75533KC be used with ceramic output capacitors only?

Yes, the TPS75533KC is stable with ceramic output capacitors ≥100 µF, provided their effective series resistance (ESR) is <10 mΩ. TI recommends using parallel combinations (e.g., 47 µF + 47 µF X7R) to meet both capacitance and ESR targets. Avoid low-ESR tantalum or polymer caps without verifying stability - Figure 19/20 in the datasheet defines the safe ESR region (0.01–0.1 Ω) for 5-A loads, which ceramics readily satisfy.

What is the minimum input voltage required for the TPS75533KC to regulate properly?

The minimum input voltage for regulation is V_OUT + V_DO(max). For the TPS75533KC, V_DO is 500 mV max at 5 A and 125°C, so V_IN(min) = 3.3 V + 0.5 V = 3.8 V. However, the recommended operating condition specifies 4.3 V ≤ V_IN ≤ 5.5 V for full 5-A performance and 3% tolerance. At lighter loads or lower temperatures, regulation begins as low as 3.55 V (3.3 V + 250 mV typical dropout), but margin shrinks with junction temperature rise.

Does the TPS75533KC support reverse current protection?

The TPS75533KC's PMOS pass transistor includes an intrinsic body diode that conducts reverse current (from OUTPUT to IN) if V_IN falls below V_OUT - for example, during power-down sequencing. This is not protected; reverse current is uncontrolled and can damage upstream sources. To prevent this, add an external Schottky diode in series with the input or use a dedicated reverse-current protection IC upstream of the TPS75533KC.